diff --git a/src/access.c b/src/access.c
index 0e075512dc3a..a2a5e607f1e6 100644
--- a/src/access.c
+++ b/src/access.c
@@ -85,7 +85,7 @@ enum PROT ClassDeclaration::getAccess(Dsymbol *smember)
         }
 
         for (i = 0; i < baseclasses->dim; i++)
-        {   BaseClass *b = (BaseClass *)baseclasses->data[i];
+        {   BaseClass *b = baseclasses->tdata()[i];
 
             access = b->base->getAccess(smember);
             switch (access)
@@ -154,7 +154,7 @@ static int accessCheckX(
             if (cdthis)
             {
                 for (int i = 0; i < cdthis->baseclasses->dim; i++)
-                {   BaseClass *b = (BaseClass *)cdthis->baseclasses->data[i];
+                {   BaseClass *b = cdthis->baseclasses->tdata()[i];
                     enum PROT access;
 
                     access = b->base->getAccess(smember);
@@ -175,7 +175,7 @@ static int accessCheckX(
             if (cdthis)
             {
                 for (int i = 0; i < cdthis->baseclasses->dim; i++)
-                {   BaseClass *b = (BaseClass *)cdthis->baseclasses->data[i];
+                {   BaseClass *b = cdthis->baseclasses->tdata()[i];
 
                     if (accessCheckX(smember, sfunc, b->base, cdscope))
                         return 1;
diff --git a/src/aggregate.h b/src/aggregate.h
index c30c787e63f8..504e2637b9f3 100644
--- a/src/aggregate.h
+++ b/src/aggregate.h
@@ -210,8 +210,8 @@ struct ClassDeclaration : AggregateDeclaration
 #endif
     FuncDeclaration *staticCtor;
     FuncDeclaration *staticDtor;
-    FuncDeclarations vtbl;              // Array of FuncDeclaration's making up the vtbl[]
-    FuncDeclarations vtblFinal;         // More FuncDeclaration's that aren't in vtbl[]
+    Dsymbols vtbl;                      // Array of FuncDeclaration's making up the vtbl[]
+    Dsymbols vtblFinal;                 // More FuncDeclaration's that aren't in vtbl[]
 
     BaseClasses *baseclasses;           // Array of BaseClass's; first is super,
                                         // rest are Interface's
diff --git a/src/arrayop.c b/src/arrayop.c
index fb89523c5c00..6cbe7ffbb9ca 100644
--- a/src/arrayop.c
+++ b/src/arrayop.c
@@ -319,7 +319,7 @@ Expression *BinExp::arrayOp(Scope *sc)
 
             Parameters *fparams = new Parameters();
             Expression *loopbody = buildArrayLoop(fparams);
-            Parameter *p = (Parameter *)fparams->data[0 /*fparams->dim - 1*/];
+            Parameter *p = fparams->tdata()[0 /*fparams->dim - 1*/];
 #if DMDV1
             // for (size_t i = 0; i < p.length; i++)
             Initializer *init = new ExpInitializer(0, new IntegerExp(0, 0, Type::tsize_t));
@@ -522,7 +522,7 @@ Expression *AssignExp::buildArrayLoop(Parameters *fparams)
     ex2 = new CastExp(0, ex2, e1->type->nextOf());
 #endif
     Expression *ex1 = e1->buildArrayLoop(fparams);
-    Parameter *param = (Parameter *)fparams->data[0];
+    Parameter *param = fparams->tdata()[0];
     param->storageClass = 0;
     Expression *e = new AssignExp(0, ex1, ex2);
     return e;
@@ -535,7 +535,7 @@ Expression *Str##AssignExp::buildArrayLoop(Parameters *fparams) \
      */                                                         \
     Expression *ex2 = e2->buildArrayLoop(fparams);              \
     Expression *ex1 = e1->buildArrayLoop(fparams);              \
-    Parameter *param = (Parameter *)fparams->data[0];           \
+    Parameter *param = fparams->tdata()[0];           \
     param->storageClass = 0;                                    \
     Expression *e = new Str##AssignExp(0, ex1, ex2);            \
     return e;                                                   \
diff --git a/src/arraytypes.h b/src/arraytypes.h
index e4440085fd27..717b47b0bc33 100644
--- a/src/arraytypes.h
+++ b/src/arraytypes.h
@@ -54,6 +54,7 @@ struct Symbol;
     void insert(unsigned index, TYPE *v) { ArrayBase::insert(index, (void *)v); } \
     void insert(unsigned index, ArrayOf_##TYPE *a) { ArrayBase::insert(index, (ArrayBase *)a); } \
     void append(ArrayOf_##TYPE *a) { ArrayBase::append((ArrayBase *)a); } \
+    void push(TYPE *a) { ArrayBase::push((void *)a); } \
     ArrayOf_##TYPE *copy() { return (ArrayOf_##TYPE *)ArrayBase::copy(); } \
 }
 
diff --git a/src/attrib.c b/src/attrib.c
index dd0d1afe003d..1eeb462690b0 100644
--- a/src/attrib.c
+++ b/src/attrib.c
@@ -55,7 +55,7 @@ int AttribDeclaration::addMember(Scope *sc, ScopeDsymbol *sd, int memnum)
     if (d)
     {
         for (unsigned i = 0; i < d->dim; i++)
-        {   Dsymbol *s = (Dsymbol *)d->data[i];
+        {   Dsymbol *s = d->tdata()[i];
             //printf("\taddMember %s to %s\n", s->toChars(), sd->toChars());
             m |= s->addMember(sc, sd, m | memnum);
         }
@@ -86,7 +86,7 @@ void AttribDeclaration::setScopeNewSc(Scope *sc,
             newsc->structalign = structalign;
         }
         for (unsigned i = 0; i < decl->dim; i++)
-        {   Dsymbol *s = (Dsymbol *)decl->data[i];
+        {   Dsymbol *s = decl->tdata()[i];
 
             s->setScope(newsc); // yes, the only difference from semanticNewSc()
         }
@@ -121,7 +121,7 @@ void AttribDeclaration::semanticNewSc(Scope *sc,
             newsc->structalign = structalign;
         }
         for (unsigned i = 0; i < decl->dim; i++)
-        {   Dsymbol *s = (Dsymbol *)decl->data[i];
+        {   Dsymbol *s = decl->tdata()[i];
 
             s->semantic(newsc);
         }
@@ -142,7 +142,7 @@ void AttribDeclaration::semantic(Scope *sc)
     {
         for (unsigned i = 0; i < d->dim; i++)
         {
-            Dsymbol *s = (Dsymbol *)d->data[i];
+            Dsymbol *s = d->tdata()[i];
 
             s->semantic(sc);
         }
@@ -156,7 +156,7 @@ void AttribDeclaration::semantic2(Scope *sc)
     if (d)
     {
         for (unsigned i = 0; i < d->dim; i++)
-        {   Dsymbol *s = (Dsymbol *)d->data[i];
+        {   Dsymbol *s = d->tdata()[i];
             s->semantic2(sc);
         }
     }
@@ -169,7 +169,7 @@ void AttribDeclaration::semantic3(Scope *sc)
     if (d)
     {
         for (unsigned i = 0; i < d->dim; i++)
-        {   Dsymbol *s = (Dsymbol *)d->data[i];
+        {   Dsymbol *s = d->tdata()[i];
             s->semantic3(sc);
         }
     }
@@ -182,7 +182,7 @@ void AttribDeclaration::inlineScan()
     if (d)
     {
         for (unsigned i = 0; i < d->dim; i++)
-        {   Dsymbol *s = (Dsymbol *)d->data[i];
+        {   Dsymbol *s = d->tdata()[i];
             //printf("AttribDeclaration::inlineScan %s\n", s->toChars());
             s->inlineScan();
         }
@@ -199,7 +199,7 @@ void AttribDeclaration::addComment(unsigned char *comment)
         if (d)
         {
             for (unsigned i = 0; i < d->dim; i++)
-            {   Dsymbol *s = (Dsymbol *)d->data[i];
+            {   Dsymbol *s = d->tdata()[i];
                 //printf("AttribDeclaration::addComment %s\n", s->toChars());
                 s->addComment(comment);
             }
@@ -224,7 +224,7 @@ void AttribDeclaration::emitComment(Scope *sc)
     if (d)
     {
         for (unsigned i = 0; i < d->dim; i++)
-        {   Dsymbol *s = (Dsymbol *)d->data[i];
+        {   Dsymbol *s = d->tdata()[i];
             //printf("AttribDeclaration::emitComment %s\n", s->toChars());
             s->emitComment(sc);
         }
@@ -238,7 +238,7 @@ void AttribDeclaration::toObjFile(int multiobj)
     if (d)
     {
         for (unsigned i = 0; i < d->dim; i++)
-        {   Dsymbol *s = (Dsymbol *)d->data[i];
+        {   Dsymbol *s = d->tdata()[i];
             s->toObjFile(multiobj);
         }
     }
@@ -253,7 +253,7 @@ int AttribDeclaration::cvMember(unsigned char *p)
     if (d)
     {
         for (unsigned i = 0; i < d->dim; i++)
-        {   Dsymbol *s = (Dsymbol *)d->data[i];
+        {   Dsymbol *s = d->tdata()[i];
             n = s->cvMember(p);
             if (p)
                 p += n;
@@ -271,7 +271,7 @@ int AttribDeclaration::hasPointers()
     {
         for (size_t i = 0; i < d->dim; i++)
         {
-            Dsymbol *s = (Dsymbol *)d->data[i];
+            Dsymbol *s = d->tdata()[i];
             if (s->hasPointers())
                 return 1;
         }
@@ -298,7 +298,7 @@ void AttribDeclaration::checkCtorConstInit()
     if (d)
     {
         for (unsigned i = 0; i < d->dim; i++)
-        {   Dsymbol *s = (Dsymbol *)d->data[i];
+        {   Dsymbol *s = d->tdata()[i];
             s->checkCtorConstInit();
         }
     }
@@ -314,7 +314,7 @@ void AttribDeclaration::addLocalClass(ClassDeclarations *aclasses)
     if (d)
     {
         for (unsigned i = 0; i < d->dim; i++)
-        {   Dsymbol *s = (Dsymbol *)d->data[i];
+        {   Dsymbol *s = d->tdata()[i];
             s->addLocalClass(aclasses);
         }
     }
@@ -328,7 +328,7 @@ void AttribDeclaration::toCBuffer(OutBuffer *buf, HdrGenState *hgs)
         if (decl->dim == 0)
             buf->writestring("{}");
         else if (decl->dim == 1)
-            ((Dsymbol *)decl->data[0])->toCBuffer(buf, hgs);
+            (decl->tdata()[0])->toCBuffer(buf, hgs);
         else
         {
             buf->writenl();
@@ -336,7 +336,7 @@ void AttribDeclaration::toCBuffer(OutBuffer *buf, HdrGenState *hgs)
             buf->writenl();
             for (unsigned i = 0; i < decl->dim; i++)
             {
-                Dsymbol *s = (Dsymbol *)decl->data[i];
+                Dsymbol *s = decl->tdata()[i];
 
                 buf->writestring("    ");
                 s->toCBuffer(buf, hgs);
@@ -528,7 +528,7 @@ void LinkDeclaration::semantic3(Scope *sc)
         sc->linkage = linkage;
         for (unsigned i = 0; i < decl->dim; i++)
         {
-            Dsymbol *s = (Dsymbol *)decl->data[i];
+            Dsymbol *s = decl->tdata()[i];
 
             s->semantic3(sc);
         }
@@ -606,7 +606,7 @@ void ProtDeclaration::importAll(Scope *sc)
 
     for (int i = 0; i < decl->dim; i++)
     {
-       Dsymbol *s = (Dsymbol *)decl->data[i];
+       Dsymbol *s = decl->tdata()[i];
        s->importAll(newsc);
     }
 
@@ -765,7 +765,7 @@ void AnonDeclaration::semantic(Scope *sc)
 
         for (unsigned i = 0; i < decl->dim; i++)
         {
-            Dsymbol *s = (Dsymbol *)decl->data[i];
+            Dsymbol *s = decl->tdata()[i];
 
             s->semantic(sc);
             if (isunion)
@@ -817,7 +817,7 @@ void AnonDeclaration::semantic(Scope *sc)
         //printf("\tadding members of aad to '%s'\n", ad->toChars());
         for (unsigned i = 0; i < aad.fields.dim; i++)
         {
-            VarDeclaration *v = (VarDeclaration *)aad.fields.data[i];
+            VarDeclaration *v = aad.fields.tdata()[i];
 
             v->offset += sc->offset;
             ad->fields.push(v);
@@ -850,7 +850,7 @@ void AnonDeclaration::toCBuffer(OutBuffer *buf, HdrGenState *hgs)
     {
         for (unsigned i = 0; i < decl->dim; i++)
         {
-            Dsymbol *s = (Dsymbol *)decl->data[i];
+            Dsymbol *s = decl->tdata()[i];
 
             //buf->writestring("    ");
             s->toCBuffer(buf, hgs);
@@ -896,10 +896,10 @@ void PragmaDeclaration::setScope(Scope *sc)
         }
         else
         {
-            Expression *e = (Expression *)args->data[0];
+            Expression *e = args->tdata()[0];
             e = e->semantic(sc);
             e = e->optimize(WANTvalue | WANTinterpret);
-            args->data[0] = (void *)e;
+            args->tdata()[0] = e;
             if (e->op != TOKstring)
             {
                 error("string expected, not '%s'", e->toChars());
@@ -928,7 +928,7 @@ void PragmaDeclaration::semantic(Scope *sc)
         {
             for (size_t i = 0; i < args->dim; i++)
             {
-                Expression *e = (Expression *)args->data[i];
+                Expression *e = args->tdata()[i];
 
                 e = e->semantic(sc);
                 e = e->optimize(WANTvalue | WANTinterpret);
@@ -950,11 +950,11 @@ void PragmaDeclaration::semantic(Scope *sc)
             error("string expected for library name");
         else
         {
-            Expression *e = (Expression *)args->data[0];
+            Expression *e = args->tdata()[0];
 
             e = e->semantic(sc);
             e = e->optimize(WANTvalue | WANTinterpret);
-            args->data[0] = (void *)e;
+            args->tdata()[0] = e;
             if (e->op == TOKerror)
                 goto Lnodecl;
             if (e->op != TOKstring)
@@ -982,7 +982,7 @@ void PragmaDeclaration::semantic(Scope *sc)
             Declaration *d = NULL;
             StringExp *s = NULL;
 
-            e = (Expression *)args->data[0];
+            e = args->tdata()[0];
             e = e->semantic(sc);
             if (e->op == TOKvar)
             {
@@ -993,7 +993,7 @@ void PragmaDeclaration::semantic(Scope *sc)
             if (!d)
                 error("first argument of GNU_asm must be a function or variable declaration");
 
-            e = (Expression *)args->data[1];
+            e = args->tdata()[1];
             e = e->semantic(sc);
             e = e->optimize(WANTvalue);
             if (e->op == TOKstring && ((StringExp *)e)->sz == 1)
@@ -1014,10 +1014,10 @@ void PragmaDeclaration::semantic(Scope *sc)
             error("function name expected for start address");
         else
         {
-            Expression *e = (Expression *)args->data[0];
+            Expression *e = args->tdata()[0];
             e = e->semantic(sc);
             e = e->optimize(WANTvalue | WANTinterpret);
-            args->data[0] = (void *)e;
+            args->tdata()[0] = e;
             Dsymbol *sa = getDsymbol(e);
             if (!sa || !sa->isFuncDeclaration())
                 error("function name expected for start address, not '%s'", e->toChars());
@@ -1041,7 +1041,7 @@ void PragmaDeclaration::semantic(Scope *sc)
             {
                 for (size_t i = 0; i < args->dim; i++)
                 {
-                    Expression *e = (Expression *)args->data[i];
+                    Expression *e = args->tdata()[i];
                     e = e->semantic(sc);
                     e = e->optimize(WANTvalue | WANTinterpret);
                     if (i == 0)
@@ -1064,7 +1064,7 @@ void PragmaDeclaration::semantic(Scope *sc)
     {
         for (unsigned i = 0; i < decl->dim; i++)
         {
-            Dsymbol *s = (Dsymbol *)decl->data[i];
+            Dsymbol *s = decl->tdata()[i];
 
             s->semantic(sc);
         }
@@ -1093,7 +1093,7 @@ void PragmaDeclaration::toObjFile(int multiobj)
     {
         assert(args && args->dim == 1);
 
-        Expression *e = (Expression *)args->data[0];
+        Expression *e = args->tdata()[0];
 
         assert(e->op == TOKstring);
 
@@ -1112,7 +1112,7 @@ void PragmaDeclaration::toObjFile(int multiobj)
          * so instead append the library name to the list to be passed
          * to the linker.
          */
-        global.params.libfiles->push((void *) name);
+        global.params.libfiles->push(name);
 #else
         error("pragma lib not supported");
 #endif
@@ -1121,7 +1121,7 @@ void PragmaDeclaration::toObjFile(int multiobj)
     else if (ident == Id::startaddress)
     {
         assert(args && args->dim == 1);
-        Expression *e = (Expression *)args->data[0];
+        Expression *e = args->tdata()[0];
         Dsymbol *sa = getDsymbol(e);
         FuncDeclaration *f = sa->isFuncDeclaration();
         assert(f);
@@ -1193,7 +1193,7 @@ void ConditionalDeclaration::emitComment(Scope *sc)
          */
         Dsymbols *d = decl ? decl : elsedecl;
         for (unsigned i = 0; i < d->dim; i++)
-        {   Dsymbol *s = (Dsymbol *)d->data[i];
+        {   Dsymbol *s = d->tdata()[i];
             s->emitComment(sc);
         }
     }
@@ -1217,7 +1217,7 @@ void ConditionalDeclaration::setScope(Scope *sc)
     {
        for (unsigned i = 0; i < d->dim; i++)
        {
-           Dsymbol *s = (Dsymbol *)d->data[i];
+           Dsymbol *s = d->tdata()[i];
 
            s->setScope(sc);
        }
@@ -1233,7 +1233,7 @@ void ConditionalDeclaration::importAll(Scope *sc)
     {
        for (unsigned i = 0; i < d->dim; i++)
        {
-           Dsymbol *s = (Dsymbol *)d->data[i];
+           Dsymbol *s = d->tdata()[i];
 
            s->importAll(sc);
        }
@@ -1259,7 +1259,7 @@ void ConditionalDeclaration::addComment(unsigned char *comment)
                 for (unsigned i = 0; i < d->dim; i++)
                 {   Dsymbol *s;
 
-                    s = (Dsymbol *)d->data[i];
+                    s = d->tdata()[i];
                     //printf("ConditionalDeclaration::addComment %s\n", s->toChars());
                     s->addComment(comment);
                 }
@@ -1281,7 +1281,7 @@ void ConditionalDeclaration::toCBuffer(OutBuffer *buf, HdrGenState *hgs)
         {
             for (unsigned i = 0; i < decl->dim; i++)
             {
-                Dsymbol *s = (Dsymbol *)decl->data[i];
+                Dsymbol *s = decl->tdata()[i];
 
                 buf->writestring("    ");
                 s->toCBuffer(buf, hgs);
@@ -1297,7 +1297,7 @@ void ConditionalDeclaration::toCBuffer(OutBuffer *buf, HdrGenState *hgs)
             buf->writenl();
             for (unsigned i = 0; i < elsedecl->dim; i++)
             {
-                Dsymbol *s = (Dsymbol *)elsedecl->data[i];
+                Dsymbol *s = elsedecl->tdata()[i];
 
                 buf->writestring("    ");
                 s->toCBuffer(buf, hgs);
@@ -1383,7 +1383,7 @@ void StaticIfDeclaration::semantic(Scope *sc)
 
         for (unsigned i = 0; i < d->dim; i++)
         {
-            Dsymbol *s = (Dsymbol *)d->data[i];
+            Dsymbol *s = d->tdata()[i];
 
             s->semantic(sc);
         }
diff --git a/src/backend/cgcv.c b/src/backend/cgcv.c
index 68ab29454519..cbc6a0cbba6f 100644
--- a/src/backend/cgcv.c
+++ b/src/backend/cgcv.c
@@ -238,7 +238,7 @@ void debtyp_check(debtyp_t *d,int linnum)
     //printf("linnum = %d\n",linnum);
     //printf(" length = %d\n",d->length);
     for (i = 0; i < d->length; i++)
-        c = d->data[i];
+        c = d->tdata()[i];
 }
 
 #define debtyp_check(d) debtyp_check(d,__LINE__);
@@ -890,7 +890,7 @@ idx_t cv4_struct(Classsym *s,int flags)
                         descriptor |= 5;
                     if (tyfarfunc(ty))
                         descriptor++;
-                    vshape->data[4 + n / 2] = descriptor;
+                    vshape->tdata()[4 + n / 2] = descriptor;
                     descriptor <<= 4;
                     n++;
                 }
@@ -930,7 +930,7 @@ printf("fwd struct ref\n");
 {int i;
  printf("len = %d, length = %d\n",len,d->length);
  for (i=0;i<d->length;i++)
- printf("%02x ",d->data[i]);
+ printf("%02x ",d->tdata()[i]);
  printf("\n");
 }
 #endif
@@ -1250,15 +1250,15 @@ printf("fwd struct ref\n");
                 if (config.fulltypes == CV4)
                 {   db = debtyp_alloc(6);
                     TOWORD(db->data,LF_BITFIELD);
-                    db->data[2] = sf->Swidth;
-                    db->data[3] = sf->Sbit;
+                    db->tdata()[2] = sf->Swidth;
+                    db->tdata()[3] = sf->Sbit;
                     TOWORD(db->data + 4,cv4_symtypidx(sf));
                 }
                 else
                 {   db = debtyp_alloc(8);
                     TOWORD(db->data,LF_BITFIELD);
-                    db->data[6] = sf->Swidth;
-                    db->data[7] = sf->Sbit;
+                    db->tdata()[6] = sf->Swidth;
+                    db->tdata()[7] = sf->Sbit;
                     TOLONG(db->data + 2,cv4_symtypidx(sf));
                 }
                 typidx = cv_debtyp(db);
@@ -1861,7 +1861,7 @@ unsigned cv4_typidx(type *t)
                 TOWORD(d->data,LF_ARRAY);
                 TOWORD(d->data + 2,next);
                 TOWORD(d->data + 4,I32 ? 0x12 : 0x11);  // T_LONG : T_SHORT
-                d->data[6 + u] = 0;             // no name
+                d->tdata()[6 + u] = 0;             // no name
                 cv4_storenumeric(d->data + 6,size);
             }
             else
@@ -1870,7 +1870,7 @@ unsigned cv4_typidx(type *t)
                 TOWORD(d->data,LF_ARRAY);
                 TOLONG(d->data + 2,next);
                 TOLONG(d->data + 6,I32 ? 0x12 : 0x11);  // T_LONG : T_SHORT
-                d->data[10 + u] = 0;            // no name
+                d->tdata()[10 + u] = 0;            // no name
                 cv4_storenumeric(d->data + 10,size);
             }
             typidx = cv_debtyp(d);
@@ -1901,8 +1901,8 @@ unsigned cv4_typidx(type *t)
             {   d = debtyp_alloc(2 + 2 + 1 + 1 + 2 + 2);
                 TOWORD(d->data,LF_PROCEDURE);
                 TOWORD(d->data + 2,next);               // return type
-                d->data[4] = call;
-                d->data[5] = 0;                 // reserved
+                d->tdata()[4] = call;
+                d->tdata()[5] = 0;                 // reserved
                 TOWORD(d->data + 6,nparam);
                 TOWORD(d->data + 8,paramidx);
             }
@@ -1910,8 +1910,8 @@ unsigned cv4_typidx(type *t)
             {   d = debtyp_alloc(2 + 4 + 1 + 1 + 2 + 4);
                 TOWORD(d->data,LF_PROCEDURE);
                 TOLONG(d->data + 2,next);               // return type
-                d->data[6] = call;
-                d->data[7] = 0;                 // reserved
+                d->tdata()[6] = call;
+                d->tdata()[7] = 0;                 // reserved
                 TOWORD(d->data + 8,nparam);
                 TOLONG(d->data + 10,paramidx);
             }
diff --git a/src/backend/cgobj.c b/src/backend/cgobj.c
index 0a24b8614394..a4985039f69c 100644
--- a/src/backend/cgobj.c
+++ b/src/backend/cgobj.c
@@ -862,8 +862,8 @@ void objlinnum(Srcpos srcpos,targ_size_t offset)
                 ln->i < LINNUMMAX - 6)
                 break;
         }
-        TOWORD(&ln->data[ln->i],linnum);
-        TOOFFSET(&ln->data[ln->i + 2],offset);
+        TOWORD(&ln->tdata()[ln->i],linnum);
+        TOOFFSET(&ln->tdata()[ln->i + 2],offset);
         ln->i += 2 + intsize;
     }
     else
@@ -1052,12 +1052,12 @@ STATIC void linnum_term()
 #endif
             for (u = 0; u < ln->i; )
             {
-                srcpos.Slinnum = *(unsigned short *)&ln->data[u];
+                srcpos.Slinnum = *(unsigned short *)&ln->tdata()[u];
                 u += 2;
                 if (I32)
-                    offset = *(unsigned long *)&ln->data[u];
+                    offset = *(unsigned long *)&ln->tdata()[u];
                 else
-                    offset = *(unsigned short *)&ln->data[u];
+                    offset = *(unsigned short *)&ln->tdata()[u];
                 objlinnum(srcpos,offset);
                 u += intsize;
             }
@@ -2909,7 +2909,7 @@ L1:     ;
   i = offset - obj.ledata->offset;
   if (obj.ledata->i <= i)
         obj.ledata->i = i + 1;
-  obj.ledata->data[i] = byte;           // 1st byte of data
+  obj.ledata->tdata()[i] = byte;           // 1st byte of data
 }
 
 /***********************************
diff --git a/src/backend/dwarf.c b/src/backend/dwarf.c
index 67a71665419f..23350158a712 100644
--- a/src/backend/dwarf.c
+++ b/src/backend/dwarf.c
@@ -548,7 +548,7 @@ void dwarf_initfile(const char *filename)
 #if 0 && MARS
     for (int i = 0; i < global.params.imppath->dim; i++)
     {
-        linebuf->writeString((char *)global.params.imppath->data[i]);
+        linebuf->writeString(global.params.imppath->tdata()[i]);
         linebuf->writeByte(0);
     }
 #endif
diff --git a/src/builtin.c b/src/builtin.c
index 6ec705e676b7..fbd42b3eed73 100644
--- a/src/builtin.c
+++ b/src/builtin.c
@@ -92,7 +92,7 @@ enum BUILTIN FuncDeclaration::isBuiltin()
 Expression *eval_builtin(enum BUILTIN builtin, Expressions *arguments)
 {
     assert(arguments && arguments->dim);
-    Expression *arg0 = (Expression *)arguments->data[0];
+    Expression *arg0 = arguments->tdata()[0];
     Expression *e = NULL;
     switch (builtin)
     {
diff --git a/src/cast.c b/src/cast.c
index de5c658d3c7b..7862bbbe6e55 100644
--- a/src/cast.c
+++ b/src/cast.c
@@ -424,7 +424,7 @@ MATCH StructLiteralExp::implicitConvTo(Type *t)
     {
         m = MATCHconst;
         for (int i = 0; i < elements->dim; i++)
-        {   Expression *e = (Expression *)elements->data[i];
+        {   Expression *e = elements->tdata()[i];
             Type *te = e->type;
             te = te->castMod(t->mod);
             MATCH m2 = e->implicitConvTo(te);
@@ -533,7 +533,7 @@ MATCH ArrayLiteralExp::implicitConvTo(Type *t)
         }
 
         for (int i = 0; i < elements->dim; i++)
-        {   Expression *e = (Expression *)elements->data[i];
+        {   Expression *e = elements->tdata()[i];
             MATCH m = (MATCH)e->implicitConvTo(tb->nextOf());
             if (m < result)
                 result = m;                     // remember worst match
@@ -554,13 +554,13 @@ MATCH AssocArrayLiteralExp::implicitConvTo(Type *t)
     if (tb->ty == Taarray && typeb->ty == Taarray)
     {
         for (size_t i = 0; i < keys->dim; i++)
-        {   Expression *e = (Expression *)keys->data[i];
+        {   Expression *e = keys->tdata()[i];
             MATCH m = (MATCH)e->implicitConvTo(((TypeAArray *)tb)->index);
             if (m < result)
                 result = m;                     // remember worst match
             if (result == MATCHnomatch)
                 break;                          // no need to check for worse
-            e = (Expression *)values->data[i];
+            e = values->tdata()[i];
             m = (MATCH)e->implicitConvTo(tb->nextOf());
             if (m < result)
                 result = m;                     // remember worst match
@@ -595,7 +595,7 @@ MATCH AddrExp::implicitConvTo(Type *t)
         {   OverExp *eo = (OverExp *)e1;
             FuncDeclaration *f = NULL;
             for (int i = 0; i < eo->vars->a.dim; i++)
-            {   Dsymbol *s = (Dsymbol *)eo->vars->a.data[i];
+            {   Dsymbol *s = eo->vars->a.tdata()[i];
                 FuncDeclaration *f2 = s->isFuncDeclaration();
                 assert(f2);
                 if (f2->overloadExactMatch(t->nextOf()))
@@ -1181,7 +1181,7 @@ Expression *AddrExp::castTo(Scope *sc, Type *t)
         {   OverExp *eo = (OverExp *)e1;
             FuncDeclaration *f = NULL;
             for (int i = 0; i < eo->vars->a.dim; i++)
-            {   Dsymbol *s = (Dsymbol *)eo->vars->a.data[i];
+            {   Dsymbol *s = eo->vars->a.tdata()[i];
                 FuncDeclaration *f2 = s->isFuncDeclaration();
                 assert(f2);
                 if (f2->overloadExactMatch(t->nextOf()))
@@ -1235,9 +1235,9 @@ Expression *TupleExp::castTo(Scope *sc, Type *t)
 {   TupleExp *e = (TupleExp *)copy();
     e->exps = (Expressions *)exps->copy();
     for (size_t i = 0; i < e->exps->dim; i++)
-    {   Expression *ex = (Expression *)e->exps->data[i];
+    {   Expression *ex = e->exps->tdata()[i];
         ex = ex->castTo(sc, t);
-        e->exps->data[i] = (void *)ex;
+        e->exps->tdata()[i] = ex;
     }
     return e;
 }
@@ -1268,9 +1268,9 @@ Expression *ArrayLiteralExp::castTo(Scope *sc, Type *t)
         e = (ArrayLiteralExp *)copy();
         e->elements = (Expressions *)elements->copy();
         for (int i = 0; i < elements->dim; i++)
-        {   Expression *ex = (Expression *)elements->data[i];
+        {   Expression *ex = elements->tdata()[i];
             ex = ex->castTo(sc, tb->nextOf());
-            e->elements->data[i] = (void *)ex;
+            e->elements->tdata()[i] = ex;
         }
         e->type = t;
         return e;
@@ -1302,13 +1302,13 @@ Expression *AssocArrayLiteralExp::castTo(Scope *sc, Type *t)
         e->values = (Expressions *)values->copy();
         assert(keys->dim == values->dim);
         for (size_t i = 0; i < keys->dim; i++)
-        {   Expression *ex = (Expression *)values->data[i];
+        {   Expression *ex = values->tdata()[i];
             ex = ex->castTo(sc, tb->nextOf());
-            e->values->data[i] = (void *)ex;
+            e->values->tdata()[i] = ex;
 
-            ex = (Expression *)keys->data[i];
+            ex = keys->tdata()[i];
             ex = ex->castTo(sc, ((TypeAArray *)tb)->index);
-            e->keys->data[i] = (void *)ex;
+            e->keys->tdata()[i] = ex;
         }
         e->type = t;
         return e;
@@ -1523,7 +1523,7 @@ bool isVoidArrayLiteral(Expression *e, Type *other)
     while (e->op == TOKarrayliteral && e->type->ty == Tarray
         && (((ArrayLiteralExp *)e)->elements->dim == 1))
     {
-        e = (Expression *)((ArrayLiteralExp *)e)->elements->data[0];
+        e = ((ArrayLiteralExp *)e)->elements->tdata()[0];
         if (other->ty == Tsarray || other->ty == Tarray)
             other = other->nextOf();
         else
diff --git a/src/class.c b/src/class.c
index 14ef9e7014a4..54fd3d42b13d 100644
--- a/src/class.c
+++ b/src/class.c
@@ -223,9 +223,9 @@ Dsymbol *ClassDeclaration::syntaxCopy(Dsymbol *s)
     cd->baseclasses->setDim(this->baseclasses->dim);
     for (int i = 0; i < cd->baseclasses->dim; i++)
     {
-        BaseClass *b = (BaseClass *)this->baseclasses->data[i];
+        BaseClass *b = this->baseclasses->tdata()[i];
         BaseClass *b2 = new BaseClass(b->type->syntaxCopy(), b->protection);
-        cd->baseclasses->data[i] = b2;
+        cd->baseclasses->tdata()[i] = b2;
     }
 
     ScopeDsymbol::syntaxCopy(cd);
@@ -290,7 +290,7 @@ void ClassDeclaration::semantic(Scope *sc)
 
     // Expand any tuples in baseclasses[]
     for (i = 0; i < baseclasses->dim; )
-    {   BaseClass *b = (BaseClass *)baseclasses->data[i];
+    {   BaseClass *b = baseclasses->tdata()[i];
 //printf("test1 %s %s\n", toChars(), b->type->toChars());
         b->type = b->type->semantic(loc, sc);
 //printf("test2\n");
@@ -317,7 +317,7 @@ void ClassDeclaration::semantic(Scope *sc)
         BaseClass *b;
         Type *tb;
 
-        b = (BaseClass *)baseclasses->data[0];
+        b = baseclasses->tdata()[0];
         //b->type = b->type->semantic(loc, sc);
         tb = b->type->toBasetype();
         if (tb->ty != Tclass)
@@ -386,7 +386,7 @@ void ClassDeclaration::semantic(Scope *sc)
         BaseClass *b;
         Type *tb;
 
-        b = (BaseClass *)baseclasses->data[i];
+        b = baseclasses->tdata()[i];
         b->type = b->type->semantic(loc, sc);
         tb = b->type->toBasetype();
         if (tb->ty == Tclass)
@@ -415,7 +415,7 @@ void ClassDeclaration::semantic(Scope *sc)
             // Check for duplicate interfaces
             for (size_t j = (baseClass ? 1 : 0); j < i; j++)
             {
-                BaseClass *b2 = (BaseClass *)baseclasses->data[j];
+                BaseClass *b2 = baseclasses->tdata()[j];
                 if (b2->base == tc->sym)
                     error("inherits from duplicate interface %s", b2->base->toChars());
             }
@@ -469,7 +469,7 @@ void ClassDeclaration::semantic(Scope *sc)
     }
 
     interfaces_dim = baseclasses->dim;
-    interfaces = (BaseClass **)baseclasses->data;
+    interfaces = baseclasses->tdata();
 
 
     if (baseClass)
@@ -482,7 +482,7 @@ void ClassDeclaration::semantic(Scope *sc)
 
         // Copy vtbl[] from base class
         vtbl.setDim(baseClass->vtbl.dim);
-        memcpy(vtbl.data, baseClass->vtbl.data, sizeof(void *) * vtbl.dim);
+        memcpy(vtbl.tdata(), baseClass->vtbl.tdata(), sizeof(void *) * vtbl.dim);
 
         // Inherit properties from base class
         com = baseClass->isCOMclass();
@@ -506,7 +506,7 @@ void ClassDeclaration::semantic(Scope *sc)
 
         for (i = 0; i < members->dim; i++)
         {
-            Dsymbol *s = (Dsymbol *)members->data[i];
+            Dsymbol *s = members->tdata()[i];
             s->addMember(sc, this, 1);
         }
 
@@ -625,7 +625,7 @@ void ClassDeclaration::semantic(Scope *sc)
      * resolve individual members like enums.
      */
     for (i = 0; i < members_dim; i++)
-    {   Dsymbol *s = (Dsymbol *)members->data[i];
+    {   Dsymbol *s = members->tdata()[i];
         /* There are problems doing this in the general case because
          * Scope keeps track of things like 'offset'
          */
@@ -637,7 +637,7 @@ void ClassDeclaration::semantic(Scope *sc)
     }
 
     for (i = 0; i < members_dim; i++)
-    {   Dsymbol *s = (Dsymbol *)members->data[i];
+    {   Dsymbol *s = members->tdata()[i];
         s->semantic(sc);
     }
 
@@ -714,7 +714,7 @@ void ClassDeclaration::semantic(Scope *sc)
     // Allocate instance of each new interface
     for (i = 0; i < vtblInterfaces->dim; i++)
     {
-        BaseClass *b = (BaseClass *)vtblInterfaces->data[i];
+        BaseClass *b = vtblInterfaces->tdata()[i];
         unsigned thissize = PTRSIZE;
 
         alignmember(structalign, thissize, &sc->offset);
@@ -744,7 +744,7 @@ void ClassDeclaration::semantic(Scope *sc)
     // Fill in base class vtbl[]s
     for (i = 0; i < vtblInterfaces->dim; i++)
     {
-        BaseClass *b = (BaseClass *)vtblInterfaces->data[i];
+        BaseClass *b = vtblInterfaces->tdata()[i];
 
         //b->fillVtbl(this, &b->vtbl, 1);
     }
@@ -763,7 +763,7 @@ void ClassDeclaration::toCBuffer(OutBuffer *buf, HdrGenState *hgs)
     }
     for (int i = 0; i < baseclasses->dim; i++)
     {
-        BaseClass *b = (BaseClass *)baseclasses->data[i];
+        BaseClass *b = baseclasses->tdata()[i];
 
         if (i)
             buf->writeByte(',');
@@ -777,7 +777,7 @@ void ClassDeclaration::toCBuffer(OutBuffer *buf, HdrGenState *hgs)
         buf->writenl();
         for (int i = 0; i < members->dim; i++)
         {
-            Dsymbol *s = (Dsymbol *)members->data[i];
+            Dsymbol *s = members->tdata()[i];
 
             buf->writestring("    ");
             s->toCBuffer(buf, hgs);
@@ -812,7 +812,7 @@ int ClassDeclaration::isBaseOf2(ClassDeclaration *cd)
         return 0;
     //printf("ClassDeclaration::isBaseOf2(this = '%s', cd = '%s')\n", toChars(), cd->toChars());
     for (int i = 0; i < cd->baseclasses->dim; i++)
-    {   BaseClass *b = (BaseClass *)cd->baseclasses->data[i];
+    {   BaseClass *b = cd->baseclasses->tdata()[i];
 
         if (b->base == this || isBaseOf2(b->base))
             return 1;
@@ -858,7 +858,7 @@ int ClassDeclaration::isBaseInfoComplete()
     if (!baseClass)
         return ident == Id::Object;
     for (int i = 0; i < baseclasses->dim; i++)
-    {   BaseClass *b = (BaseClass *)baseclasses->data[i];
+    {   BaseClass *b = baseclasses->tdata()[i];
         if (!b->base || !b->base->isBaseInfoComplete())
             return 0;
     }
@@ -893,7 +893,7 @@ Dsymbol *ClassDeclaration::search(Loc loc, Identifier *ident, int flags)
 
         for (i = 0; i < baseclasses->dim; i++)
         {
-            BaseClass *b = (BaseClass *)baseclasses->data[i];
+            BaseClass *b = baseclasses->tdata()[i];
 
             if (b->base)
             {
@@ -941,7 +941,7 @@ int ClassDeclaration::isFuncHidden(FuncDeclaration *fd)
     if (os)
     {
         for (int i = 0; i < os->a.dim; i++)
-        {   Dsymbol *s = (Dsymbol *)os->a.data[i];
+        {   Dsymbol *s = os->a.tdata()[i];
             FuncDeclaration *f2 = s->isFuncDeclaration();
             if (f2 && overloadApply(f2, &isf, fd))
                 return 0;
@@ -967,12 +967,12 @@ FuncDeclaration *ClassDeclaration::findFunc(Identifier *ident, TypeFunction *tf)
     //printf("ClassDeclaration::findFunc(%s, %s) %s\n", ident->toChars(), tf->toChars(), toChars());
 
     ClassDeclaration *cd = this;
-    FuncDeclarations *vtbl = &cd->vtbl;
+    Dsymbols *vtbl = &cd->vtbl;
     while (1)
     {
         for (size_t i = 0; i < vtbl->dim; i++)
         {
-            FuncDeclaration *fd = ((Dsymbol*)vtbl->data[i])->isFuncDeclaration();
+            FuncDeclaration *fd = vtbl->tdata()[i]->isFuncDeclaration();
             if (!fd)
                 continue;               // the first entry might be a ClassInfo
 
@@ -1049,7 +1049,7 @@ int ClassDeclaration::isAbstract()
         return TRUE;
     for (int i = 1; i < vtbl.dim; i++)
     {
-        FuncDeclaration *fd = ((Dsymbol *)vtbl.data[i])->isFuncDeclaration();
+        FuncDeclaration *fd = vtbl.tdata()[i]->isFuncDeclaration();
 
         //printf("\tvtbl[%d] = %p\n", i, fd);
         if (!fd || fd->isAbstract())
@@ -1156,7 +1156,7 @@ void InterfaceDeclaration::semantic(Scope *sc)
 
     // Expand any tuples in baseclasses[]
     for (i = 0; i < baseclasses->dim; )
-    {   BaseClass *b = (BaseClass *)baseclasses->data[0];
+    {   BaseClass *b = baseclasses->tdata()[0];
         b->type = b->type->semantic(loc, sc);
         Type *tb = b->type->toBasetype();
 
@@ -1184,7 +1184,7 @@ void InterfaceDeclaration::semantic(Scope *sc)
         BaseClass *b;
         Type *tb;
 
-        b = (BaseClass *)baseclasses->data[i];
+        b = baseclasses->tdata()[i];
         b->type = b->type->semantic(loc, sc);
         tb = b->type->toBasetype();
         if (tb->ty == Tclass)
@@ -1202,7 +1202,7 @@ void InterfaceDeclaration::semantic(Scope *sc)
             // Check for duplicate interfaces
             for (size_t j = 0; j < i; j++)
             {
-                BaseClass *b2 = (BaseClass *)baseclasses->data[j];
+                BaseClass *b2 = baseclasses->tdata()[j];
                 if (b2->base == tc->sym)
                     error("inherits from duplicate interface %s", b2->base->toChars());
             }
@@ -1238,7 +1238,7 @@ void InterfaceDeclaration::semantic(Scope *sc)
     }
 
     interfaces_dim = baseclasses->dim;
-    interfaces = (BaseClass **)baseclasses->data;
+    interfaces = baseclasses->tdata();
 
     interfaceSemantic(sc);
 
@@ -1263,7 +1263,7 @@ void InterfaceDeclaration::semantic(Scope *sc)
             {
                 vtbl.reserve(d - 1);
                 for (int j = 1; j < d; j++)
-                    vtbl.push(b->base->vtbl.data[j]);
+                    vtbl.push(b->base->vtbl.tdata()[j]);
             }
         }
         else
@@ -1280,7 +1280,7 @@ void InterfaceDeclaration::semantic(Scope *sc)
 
     for (i = 0; i < members->dim; i++)
     {
-        Dsymbol *s = (Dsymbol *)members->data[i];
+        Dsymbol *s = members->tdata()[i];
         s->addMember(sc, this, 1);
     }
 
@@ -1299,7 +1299,7 @@ void InterfaceDeclaration::semantic(Scope *sc)
     inuse++;
     for (i = 0; i < members->dim; i++)
     {
-        Dsymbol *s = (Dsymbol *)members->data[i];
+        Dsymbol *s = members->tdata()[i];
         s->semantic(sc);
     }
     inuse--;
@@ -1393,7 +1393,7 @@ int InterfaceDeclaration::isBaseInfoComplete()
 {
     assert(!baseClass);
     for (int i = 0; i < baseclasses->dim; i++)
-    {   BaseClass *b = (BaseClass *)baseclasses->data[i];
+    {   BaseClass *b = baseclasses->tdata()[i];
         if (!b->base || !b->base->isBaseInfoComplete ())
             return 0;
     }
@@ -1478,7 +1478,7 @@ int BaseClass::fillVtbl(ClassDeclaration *cd, FuncDeclarations *vtbl, int newins
     // first entry is ClassInfo reference
     for (j = base->vtblOffset(); j < base->vtbl.dim; j++)
     {
-        FuncDeclaration *ifd = ((Dsymbol *)base->vtbl.data[j])->isFuncDeclaration();
+        FuncDeclaration *ifd = base->vtbl.tdata()[j]->isFuncDeclaration();
         FuncDeclaration *fd;
         TypeFunction *tf;
 
@@ -1515,7 +1515,7 @@ int BaseClass::fillVtbl(ClassDeclaration *cd, FuncDeclarations *vtbl, int newins
             fd = NULL;
         }
         if (vtbl)
-            vtbl->data[j] = fd;
+            vtbl->tdata()[j] = fd;
     }
 
     return result;
diff --git a/src/clone.c b/src/clone.c
index 9d568f86bf35..0ff7e21ebcf9 100644
--- a/src/clone.c
+++ b/src/clone.c
@@ -44,7 +44,7 @@ int StructDeclaration::needOpAssign()
      */
     for (size_t i = 0; i < fields.dim; i++)
     {
-        Dsymbol *s = (Dsymbol *)fields.data[i];
+        Dsymbol *s = fields.tdata()[i];
         VarDeclaration *v = s->isVarDeclaration();
         assert(v && v->storage_class & STCfield);
         if (v->storage_class & STCref)
@@ -87,7 +87,7 @@ int StructDeclaration::needOpEquals()
      */
     for (size_t i = 0; i < fields.dim; i++)
     {
-        Dsymbol *s = (Dsymbol *)fields.data[i];
+        Dsymbol *s = fields.tdata()[i];
         VarDeclaration *v = s->isVarDeclaration();
         assert(v && v->storage_class & STCfield);
         if (v->storage_class & STCref)
@@ -196,7 +196,7 @@ FuncDeclaration *StructDeclaration::buildOpAssign(Scope *sc)
         //printf("\tmemberwise copy\n");
         for (size_t i = 0; i < fields.dim; i++)
         {
-            Dsymbol *s = (Dsymbol *)fields.data[i];
+            Dsymbol *s = fields.tdata()[i];
             VarDeclaration *v = s->isVarDeclaration();
             assert(v && v->storage_class & STCfield);
             // this.v = s.v;
@@ -267,7 +267,7 @@ FuncDeclaration *StructDeclaration::buildOpEquals(Scope *sc)
     //printf("\tmemberwise compare\n");
     for (size_t i = 0; i < fields.dim; i++)
     {
-        Dsymbol *s = (Dsymbol *)fields.data[i];
+        Dsymbol *s = fields.tdata()[i];
         VarDeclaration *v = s->isVarDeclaration();
         assert(v && v->storage_class & STCfield);
         if (v->storage_class & STCref)
@@ -385,7 +385,7 @@ FuncDeclaration *StructDeclaration::buildPostBlit(Scope *sc)
 
     for (size_t i = 0; i < fields.dim; i++)
     {
-        Dsymbol *s = (Dsymbol *)fields.data[i];
+        Dsymbol *s = fields.tdata()[i];
         VarDeclaration *v = s->isVarDeclaration();
         assert(v && v->storage_class & STCfield);
         if (v->storage_class & STCref)
@@ -448,12 +448,12 @@ FuncDeclaration *StructDeclaration::buildPostBlit(Scope *sc)
             return NULL;
 
         case 1:
-            return (FuncDeclaration *)postblits.data[0];
+            return postblits.tdata()[0];
 
         default:
             e = NULL;
             for (size_t i = 0; i < postblits.dim; i++)
-            {   FuncDeclaration *fd = (FuncDeclaration *)postblits.data[i];
+            {   FuncDeclaration *fd = postblits.tdata()[i];
                 stc |= fd->storage_class & STCdisable;
                 Expression *ex = new ThisExp(0);
                 ex = new DotVarExp(0, ex, fd, 0);
@@ -487,7 +487,7 @@ FuncDeclaration *AggregateDeclaration::buildDtor(Scope *sc)
 #if DMDV2
     for (size_t i = 0; i < fields.dim; i++)
     {
-        Dsymbol *s = (Dsymbol *)fields.data[i];
+        Dsymbol *s = fields.tdata()[i];
         VarDeclaration *v = s->isVarDeclaration();
         assert(v && v->storage_class & STCfield);
         if (v->storage_class & STCref)
@@ -548,12 +548,12 @@ FuncDeclaration *AggregateDeclaration::buildDtor(Scope *sc)
             return NULL;
 
         case 1:
-            return (FuncDeclaration *)dtors.data[0];
+            return dtors.tdata()[0];
 
         default:
             e = NULL;
             for (size_t i = 0; i < dtors.dim; i++)
-            {   FuncDeclaration *fd = (FuncDeclaration *)dtors.data[i];
+            {   FuncDeclaration *fd = dtors.tdata()[i];
                 Expression *ex = new ThisExp(0);
                 ex = new DotVarExp(0, ex, fd, 0);
                 ex = new CallExp(0, ex);
diff --git a/src/cond.c b/src/cond.c
index 2131d35ebeae..9e14191363af 100644
--- a/src/cond.c
+++ b/src/cond.c
@@ -25,13 +25,13 @@
 #include "scope.h"
 #endif
 
-int findCondition(Identifiers *ids, Identifier *ident)
+int findCondition(Strings *ids, Identifier *ident)
 {
     if (ids)
     {
         for (int i = 0; i < ids->dim; i++)
         {
-            const char *id = (const char *)ids->data[i];
+            const char *id = ids->tdata()[i];
 
             if (strcmp(id, ident->toChars()) == 0)
                 return TRUE;
@@ -74,8 +74,8 @@ void DebugCondition::setGlobalLevel(unsigned level)
 void DebugCondition::addGlobalIdent(const char *ident)
 {
     if (!global.params.debugids)
-        global.params.debugids = new Identifiers();
-    global.params.debugids->push((void *)ident);
+        global.params.debugids = new Strings();
+    global.params.debugids->push((char *)ident);
 }
 
 
@@ -98,7 +98,7 @@ int DebugCondition::include(Scope *sc, ScopeDsymbol *s)
                 inc = 1;
             else
             {   if (!mod->debugidsNot)
-                    mod->debugidsNot = new Identifiers();
+                    mod->debugidsNot = new Strings();
                 mod->debugidsNot->push(ident->toChars());
             }
         }
@@ -168,8 +168,8 @@ void VersionCondition::addGlobalIdent(const char *ident)
 void VersionCondition::addPredefinedGlobalIdent(const char *ident)
 {
     if (!global.params.versionids)
-        global.params.versionids = new Identifiers();
-    global.params.versionids->push((void *)ident);
+        global.params.versionids = new Strings();
+    global.params.versionids->push((char *)ident);
 }
 
 
@@ -194,7 +194,7 @@ int VersionCondition::include(Scope *sc, ScopeDsymbol *s)
             else
             {
                 if (!mod->versionidsNot)
-                    mod->versionidsNot = new Identifiers();
+                    mod->versionidsNot = new Strings();
                 mod->versionidsNot->push(ident->toChars());
             }
         }
@@ -322,7 +322,7 @@ int IftypeCondition::include(Scope *sc, ScopeDsymbol *sd)
 
             TemplateParameters parameters;
             parameters.setDim(1);
-            parameters.data[0] = (void *)&tp;
+            parameters.tdata()[0] = &tp;
 
             Objects dedtypes;
             dedtypes.setDim(1);
@@ -334,7 +334,7 @@ int IftypeCondition::include(Scope *sc, ScopeDsymbol *sd)
             else
             {
                 inc = 1;
-                Type *tded = (Type *)dedtypes.data[0];
+                Type *tded = (Type *)dedtypes.tdata()[0];
                 if (!tded)
                     tded = targ;
                 Dsymbol *s = new AliasDeclaration(loc, id, tded);
diff --git a/src/cond.h b/src/cond.h
index f547e695e4ce..54928d1563b9 100644
--- a/src/cond.h
+++ b/src/cond.h
@@ -26,7 +26,7 @@ enum TOK;
 struct HdrGenState;
 #endif
 
-int findCondition(Identifiers *ids, Identifier *ident);
+int findCondition(Strings *ids, Identifier *ident);
 
 struct Condition
 {
diff --git a/src/constfold.c b/src/constfold.c
index b2b2088c80a0..8c6f9d58a61b 100644
--- a/src/constfold.c
+++ b/src/constfold.c
@@ -724,8 +724,8 @@ Expression *Equal(enum TOK op, Type *type, Expression *e1, Expression *e2)
         else
         {
             for (size_t i = 0; i < es1->elements->dim; i++)
-            {   Expression *ee1 = (Expression *)es1->elements->data[i];
-                Expression *ee2 = (Expression *)es2->elements->data[i];
+            {   Expression *ee1 = es1->elements->tdata()[i];
+                Expression *ee2 = es2->elements->tdata()[i];
 
                 Expression *v = Equal(TOKequal, Type::tint32, ee1, ee2);
                 if (v == EXP_CANT_INTERPRET)
@@ -757,7 +757,7 @@ Expression *Equal(enum TOK op, Type *type, Expression *e1, Expression *e2)
             for (size_t i = 0; i < dim1; i++)
             {
                 uinteger_t c = es1->charAt(i);
-                Expression *ee2 = (Expression *)es2->elements->data[i];
+                Expression *ee2 = es2->elements->tdata()[i];
                 if (ee2->isConst() != 1)
                     return EXP_CANT_INTERPRET;
                 cmp = (c == ee2->toInteger());
@@ -783,8 +783,8 @@ Expression *Equal(enum TOK op, Type *type, Expression *e1, Expression *e2)
         {
             cmp = 1;
             for (size_t i = 0; i < es1->elements->dim; i++)
-            {   Expression *ee1 = (Expression *)es1->elements->data[i];
-                Expression *ee2 = (Expression *)es2->elements->data[i];
+            {   Expression *ee1 = es1->elements->tdata()[i];
+                Expression *ee2 = es2->elements->tdata()[i];
 
                 if (ee1 == ee2)
                     continue;
@@ -1158,7 +1158,7 @@ Expression *Cast(Type *type, Type *to, Expression *e1)
         assert(sd);
         Expressions *elements = new Expressions;
         for (size_t i = 0; i < sd->fields.dim; i++)
-        {   Dsymbol *s = (Dsymbol *)sd->fields.data[i];
+        {   Dsymbol *s = sd->fields.tdata()[i];
             VarDeclaration *v = s->isVarDeclaration();
             assert(v);
 
@@ -1237,7 +1237,7 @@ Expression *Index(Type *type, Expression *e1, Expression *e2)
         }
         else if (e1->op == TOKarrayliteral && !e1->checkSideEffect(2))
         {   ArrayLiteralExp *ale = (ArrayLiteralExp *)e1;
-            e = (Expression *)ale->elements->data[i];
+            e = ale->elements->tdata()[i];
             e->type = type;
         }
     }
@@ -1251,7 +1251,7 @@ Expression *Index(Type *type, Expression *e1, Expression *e2)
             {   e2->error("array index %ju is out of bounds %s[0 .. %u]", i, e1->toChars(), ale->elements->dim);
             }
             else
-            {   e = (Expression *)ale->elements->data[i];
+            {   e = ale->elements->tdata()[i];
                 e->type = type;
             }
         }
@@ -1264,12 +1264,12 @@ Expression *Index(Type *type, Expression *e1, Expression *e2)
         for (size_t i = ae->keys->dim; i;)
         {
             i--;
-            Expression *ekey = (Expression *)ae->keys->data[i];
+            Expression *ekey = ae->keys->tdata()[i];
             Expression *ex = Equal(TOKequal, Type::tbool, ekey, e2);
             if (ex == EXP_CANT_INTERPRET)
                 return ex;
             if (ex->isBool(TRUE))
-            {   e = (Expression *)ae->values->data[i];
+            {   e = ae->values->tdata()[i];
                 e->type = type;
                 break;
             }
@@ -1330,9 +1330,9 @@ Expression *Slice(Type *type, Expression *e1, Expression *lwr, Expression *upr)
         {
             Expressions *elements = new Expressions();
             elements->setDim(iupr - ilwr);
-            memcpy(elements->data,
-                   es1->elements->data + ilwr,
-                   (iupr - ilwr) * sizeof(es1->elements->data[0]));
+            memcpy(elements->tdata(),
+                   es1->elements->tdata() + ilwr,
+                   (iupr - ilwr) * sizeof(es1->elements->tdata()[0]));
             e = new ArrayLiteralExp(e1->loc, elements);
             e->type = type;
         }
@@ -1445,7 +1445,7 @@ Expression *Cat(Type *type, Expression *e1, Expression *e2)
         void *s = mem.malloc((len + 1) * sz);
         memcpy((char *)s + sz * es2->elements->dim, es1->string, es1->len * sz);
         for (int i = 0; i < es2->elements->dim; i++)
-        {   Expression *es2e = (Expression *)es2->elements->data[i];
+        {   Expression *es2e = es2->elements->tdata()[i];
             if (es2e->op != TOKint64)
                 return EXP_CANT_INTERPRET;
             dinteger_t v = es2e->toInteger();
@@ -1473,7 +1473,7 @@ Expression *Cat(Type *type, Expression *e1, Expression *e2)
         void *s = mem.malloc((len + 1) * sz);
         memcpy(s, es1->string, es1->len * sz);
         for (int i = 0; i < es2->elements->dim; i++)
-        {   Expression *es2e = (Expression *)es2->elements->data[i];
+        {   Expression *es2e = es2->elements->tdata()[i];
             if (es2e->op != TOKint64)
                 return EXP_CANT_INTERPRET;
             dinteger_t v = es2e->toInteger();
diff --git a/src/cppmangle.c b/src/cppmangle.c
index edb477cde3ff..a6ef4c263c93 100644
--- a/src/cppmangle.c
+++ b/src/cppmangle.c
@@ -69,7 +69,7 @@ int CppMangleState::substitute(OutBuffer *buf, void *p)
 {
     for (size_t i = 0; i < components.dim; i++)
     {
-        if (p == components.data[i])
+        if (p == components.tdata()[i])
         {
             /* Sequence is S_, S0_, .., S9_, SA_, ..., SZ_, S10_, ...
              */
@@ -88,7 +88,7 @@ int CppMangleState::exist(void *p)
 {
     for (size_t i = 0; i < components.dim; i++)
     {
-        if (p == components.data[i])
+        if (p == components.tdata()[i])
         {
             return 1;
         }
@@ -409,7 +409,7 @@ void Parameter::argsCppMangle(OutBuffer *buf, CppMangleState *cms, Parameters *a
     if (arguments)
     {
         for (size_t i = 0; i < arguments->dim; i++)
-        {   Parameter *arg = (Parameter *)arguments->data[i];
+        {   Parameter *arg = arguments->tdata()[i];
             Type *t = arg->type;
             if (arg->storageClass & (STCout | STCref))
                 t = t->referenceTo();
diff --git a/src/declaration.c b/src/declaration.c
index f17864c09713..3ba8b5d17113 100644
--- a/src/declaration.c
+++ b/src/declaration.c
@@ -185,7 +185,7 @@ Type *TupleDeclaration::getType()
         /* It's only a type tuple if all the Object's are types
          */
         for (size_t i = 0; i < objects->dim; i++)
-        {   Object *o = (Object *)objects->data[i];
+        {   Object *o = objects->tdata()[i];
 
             if (o->dyncast() != DYNCAST_TYPE)
             {
@@ -196,12 +196,13 @@ Type *TupleDeclaration::getType()
 
         /* We know it's a type tuple, so build the TypeTuple
          */
+        Types *types = (Types *)objects;
         Parameters *args = new Parameters();
         args->setDim(objects->dim);
         OutBuffer buf;
         int hasdeco = 1;
-        for (size_t i = 0; i < objects->dim; i++)
-        {   Type *t = (Type *)objects->data[i];
+        for (size_t i = 0; i < types->dim; i++)
+        {   Type *t = types->tdata()[i];
 
             //printf("type = %s\n", t->toChars());
 #if 0
@@ -212,7 +213,7 @@ Type *TupleDeclaration::getType()
 #else
             Parameter *arg = new Parameter(0, t, NULL, NULL);
 #endif
-            args->data[i] = (void *)arg;
+            args->tdata()[i] = arg;
             if (!t->deco)
                 hasdeco = 0;
         }
@@ -229,7 +230,7 @@ int TupleDeclaration::needThis()
 {
     //printf("TupleDeclaration::needThis(%s)\n", toChars());
     for (size_t i = 0; i < objects->dim; i++)
-    {   Object *o = (Object *)objects->data[i];
+    {   Object *o = objects->tdata()[i];
         if (o->dyncast() == DYNCAST_EXPRESSION)
         {   Expression *e = (Expression *)o;
             if (e->op == TOKdsymbol)
@@ -862,7 +863,7 @@ void VarDeclaration::semantic(Scope *sc)
 
             Expression *einit = ie;
             if (ie && ie->op == TOKtuple)
-            {   einit = (Expression *)((TupleExp *)ie)->exps->data[i];
+            {   einit = ((TupleExp *)ie)->exps->tdata()[i];
             }
             Initializer *ti = init;
             if (einit)
@@ -880,7 +881,7 @@ void VarDeclaration::semantic(Scope *sc)
             }
 
             Expression *e = new DsymbolExp(loc, v);
-            exps->data[i] = e;
+            exps->tdata()[i] = e;
         }
         TupleDeclaration *v2 = new TupleDeclaration(loc, ident, exps);
         v2->isexp = 1;
@@ -1501,7 +1502,7 @@ void VarDeclaration::checkNestedReference(Scope *sc, Loc loc)
                 fdthis->getLevel(loc, fdv);
 
             for (int i = 0; i < nestedrefs.dim; i++)
-            {   FuncDeclaration *f = (FuncDeclaration *)nestedrefs.data[i];
+            {   FuncDeclaration *f = nestedrefs.tdata()[i];
                 if (f == fdthis)
                     goto L1;
             }
@@ -1510,7 +1511,7 @@ void VarDeclaration::checkNestedReference(Scope *sc, Loc loc)
 
 
             for (int i = 0; i < fdv->closureVars.dim; i++)
-            {   Dsymbol *s = (Dsymbol *)fdv->closureVars.data[i];
+            {   Dsymbol *s = fdv->closureVars.tdata()[i];
                 if (s == this)
                     goto L2;
             }
diff --git a/src/declaration.h b/src/declaration.h
index e55807470b7a..46905cc11f6f 100644
--- a/src/declaration.h
+++ b/src/declaration.h
@@ -542,7 +542,7 @@ struct FuncDeclaration : Declaration
     VarDeclaration *v_argptr;           // '_argptr' variable
 #endif
     VarDeclaration *v_argsave;          // save area for args passed in registers for variadic functions
-    Dsymbols *parameters;               // Array of VarDeclaration's for parameters
+    VarDeclarations *parameters;        // Array of VarDeclaration's for parameters
     DsymbolTable *labtab;               // statement label symbol table
     Declaration *overnext;              // next in overload list
     Loc endloc;                         // location of closing curly bracket
@@ -580,7 +580,7 @@ struct FuncDeclaration : Declaration
 
     int tookAddressOf;                  // set if someone took the address of
                                         // this function
-    Dsymbols closureVars;               // local variables in this function
+    VarDeclarations closureVars;        // local variables in this function
                                         // which are referenced by nested
                                         // functions
 #else
@@ -599,7 +599,7 @@ struct FuncDeclaration : Declaration
     void toCBuffer(OutBuffer *buf, HdrGenState *hgs);
     void bodyToCBuffer(OutBuffer *buf, HdrGenState *hgs);
     int overrides(FuncDeclaration *fd);
-    int findVtblIndex(FuncDeclarations *vtbl, int dim);
+    int findVtblIndex(Dsymbols *vtbl, int dim);
     int overloadInsert(Dsymbol *s);
     FuncDeclaration *overloadExactMatch(Type *t);
     FuncDeclaration *overloadResolve(Loc loc, Expression *ethis, Expressions *arguments, int flags = 0);
diff --git a/src/delegatize.c b/src/delegatize.c
index 3f5b7257bea0..127523b6e4fe 100644
--- a/src/delegatize.c
+++ b/src/delegatize.c
@@ -61,7 +61,7 @@ void arrayExpressionScanForNestedRef(Scope *sc, Expressions *a)
     if (a)
     {
         for (int i = 0; i < a->dim; i++)
-        {   Expression *e = (Expression *)a->data[i];
+        {   Expression *e = a->tdata()[i];
 
             if (e)
             {
diff --git a/src/doc.c b/src/doc.c
index defa32a25354..5fe3c26768ba 100644
--- a/src/doc.c
+++ b/src/doc.c
@@ -226,7 +226,7 @@ void Module::gendocfile()
         // Override with the ddoc macro files from the command line
         for (int i = 0; i < global.params.ddocfiles->dim; i++)
         {
-            FileName f((char *)global.params.ddocfiles->data[i], 0);
+            FileName f(global.params.ddocfiles->tdata()[i], 0);
             File file(&f);
             file.readv();
             // BUG: convert file contents to UTF-8 before use
@@ -523,7 +523,7 @@ void ScopeDsymbol::emitMemberComments(Scope *sc)
         sc = sc->push(this);
         for (int i = 0; i < members->dim; i++)
         {
-            Dsymbol *s = (Dsymbol *)members->data[i];
+            Dsymbol *s = members->tdata()[i];
             //printf("\ts = '%s'\n", s->toChars());
             s->emitComment(sc);
         }
@@ -695,7 +695,7 @@ void EnumDeclaration::emitComment(Scope *sc)
         {
             for (int i = 0; i < members->dim; i++)
             {
-                Dsymbol *s = (Dsymbol *)members->data[i];
+                Dsymbol *s = members->tdata()[i];
                 s->emitComment(sc);
             }
             return;
@@ -878,7 +878,7 @@ void FuncDeclaration::toDocBuffer(OutBuffer *buf)
             buf->writeByte('(');
             for (int i = 0; i < td->origParameters->dim; i++)
             {
-                TemplateParameter *tp = (TemplateParameter *)td->origParameters->data[i];
+                TemplateParameter *tp = td->origParameters->tdata()[i];
                 if (i)
                     buf->writestring(", ");
                 tp->toCBuffer(buf, &hgs);
@@ -958,7 +958,7 @@ void ClassDeclaration::toDocBuffer(OutBuffer *buf)
         }
         int any = 0;
         for (int i = 0; i < baseclasses->dim; i++)
-        {   BaseClass *bc = (BaseClass *)baseclasses->data[i];
+        {   BaseClass *bc = baseclasses->tdata()[i];
 
             if (bc->protection == PROTprivate)
                 continue;
@@ -1026,7 +1026,7 @@ DocComment *DocComment::parse(Scope *sc, Dsymbol *s, unsigned char *comment)
     dc->parseSections(comment);
 
     for (int i = 0; i < dc->sections.dim; i++)
-    {   Section *s = (Section *)dc->sections.data[i];
+    {   Section *s = dc->sections.tdata()[i];
 
         if (icmp("copyright", s->name, s->namelen) == 0)
         {
@@ -1171,7 +1171,7 @@ void DocComment::writeSections(Scope *sc, Dsymbol *s, OutBuffer *buf)
     {
         buf->writestring("$(DDOC_SECTIONS \n");
         for (int i = 0; i < sections.dim; i++)
-        {   Section *sec = (Section *)sections.data[i];
+        {   Section *sec = sections.tdata()[i];
 
             if (sec->nooutput)
                 continue;
@@ -1748,7 +1748,7 @@ Parameter *isFunctionParameter(Dsymbol *s, unsigned char *p, unsigned len)
         if (tf->parameters)
         {
             for (size_t k = 0; k < tf->parameters->dim; k++)
-            {   Parameter *arg = (Parameter *)tf->parameters->data[k];
+            {   Parameter *arg = tf->parameters->tdata()[k];
 
                 if (arg->ident && cmp(arg->ident->toChars(), p, len) == 0)
                 {
diff --git a/src/dsymbol.c b/src/dsymbol.c
index 5bf1b46c1061..32a771ff1e9f 100644
--- a/src/dsymbol.c
+++ b/src/dsymbol.c
@@ -113,7 +113,7 @@ int Dsymbol::oneMembers(Dsymbols *members, Dsymbol **ps)
     if (members)
     {
         for (int i = 0; i < members->dim; i++)
-        {   Dsymbol *sx = (Dsymbol *)members->data[i];
+        {   Dsymbol *sx = members->tdata()[i];
 
             int x = sx->oneMember(ps);
             //printf("\t[%d] kind %s = %d, s = %p\n", i, sx->kind(), x, *ps);
@@ -666,10 +666,10 @@ Dsymbols *Dsymbol::arraySyntaxCopy(Dsymbols *a)
         b = (Dsymbols *)a->copy();
         for (int i = 0; i < b->dim; i++)
         {
-            Dsymbol *s = (Dsymbol *)b->data[i];
+            Dsymbol *s = b->tdata()[i];
 
             s = s->syntaxCopy(NULL);
-            b->data[i] = (void *)s;
+            b->tdata()[i] = s;
         }
     }
     return b;
@@ -767,7 +767,7 @@ Dsymbol *ScopeDsymbol::search(Loc loc, Identifier *ident, int flags)
 
         // Look in imported modules
         for (int i = 0; i < imports->dim; i++)
-        {   ScopeDsymbol *ss = (ScopeDsymbol *)imports->data[i];
+        {   ScopeDsymbol *ss = imports->tdata()[i];
             Dsymbol *s2;
 
             // If private import, don't search it
@@ -815,11 +815,11 @@ Dsymbol *ScopeDsymbol::search(Loc loc, Identifier *ident, int flags)
                             /* Don't add to a[] if s2 is alias of previous sym
                              */
                             for (int j = 0; j < a->a.dim; j++)
-                            {   Dsymbol *s3 = (Dsymbol *)a->a.data[j];
+                            {   Dsymbol *s3 = a->a.tdata()[j];
                                 if (s2->toAlias() == s3->toAlias())
                                 {
                                     if (s3->isDeprecated())
-                                        a->a.data[j] = (void *)s2;
+                                        a->a.tdata()[j] = s2;
                                     goto Lcontinue;
                                 }
                             }
@@ -871,7 +871,7 @@ void ScopeDsymbol::importScope(ScopeDsymbol *s, enum PROT protection)
             for (int i = 0; i < imports->dim; i++)
             {   ScopeDsymbol *ss;
 
-                ss = (ScopeDsymbol *) imports->data[i];
+                ss = imports->tdata()[i];
                 if (ss == s)                    // if already imported
                 {
                     if (protection > prots[i])
@@ -966,7 +966,7 @@ size_t ScopeDsymbol::dim(Dsymbols *members)
     if (members)
     {
         for (size_t i = 0; i < members->dim; i++)
-        {   Dsymbol *s = (Dsymbol *)members->data[i];
+        {   Dsymbol *s = members->tdata()[i];
             AttribDeclaration *a = s->isAttribDeclaration();
 
             if (a)
@@ -997,7 +997,7 @@ Dsymbol *ScopeDsymbol::getNth(Dsymbols *members, size_t nth, size_t *pn)
 
     size_t n = 0;
     for (size_t i = 0; i < members->dim; i++)
-    {   Dsymbol *s = (Dsymbol *)members->data[i];
+    {   Dsymbol *s = members->tdata()[i];
         AttribDeclaration *a = s->isAttribDeclaration();
 
         if (a)
diff --git a/src/dump.c b/src/dump.c
index c443d94e1e75..4fd0d04e70d8 100644
--- a/src/dump.c
+++ b/src/dump.c
@@ -36,7 +36,7 @@ void dumpExpressions(int i, Expressions *exps)
     if (exps)
     {
         for (size_t j = 0; j < exps->dim; j++)
-        {   Expression *e = (Expression *)exps->data[j];
+        {   Expression *e = exps->tdata()[j];
             indent(i);
             printf("(\n");
             e->dump(i + 2);
diff --git a/src/e2ir.c b/src/e2ir.c
index 51d537ed19e6..ec3bef09e7e6 100644
--- a/src/e2ir.c
+++ b/src/e2ir.c
@@ -44,6 +44,7 @@
 static char __file__[] = __FILE__;      /* for tassert.h                */
 #include        "tassert.h"
 
+typedef ArrayOf(elem) Elems;
 
 elem *addressElem(elem *e, Type *t);
 elem *array_toPtr(Type *t, elem *e);
@@ -127,7 +128,7 @@ elem *callfunc(Loc loc,
         int j = (tf->linkage == LINKd && tf->varargs == 1);
 
         for (i = 0; i < arguments->dim ; i++)
-        {   Expression *arg = (Expression *)arguments->data[i];
+        {   Expression *arg = arguments->tdata()[i];
             elem *ea;
 
             //printf("\targ[%d]: %s\n", i, arg->toChars());
@@ -1142,7 +1143,7 @@ elem *Dsymbol_toElem(Dsymbol *s, IRState *irs)
         {
             for (size_t i = 0; i < decl->dim; i++)
             {
-                s = (Dsymbol *)decl->data[i];
+                s = decl->tdata()[i];
                 e = el_combine(e, Dsymbol_toElem(s, irs));
             }
         }
@@ -1178,7 +1179,7 @@ elem *Dsymbol_toElem(Dsymbol *s, IRState *irs)
 
                 // Put vd on list of things needing destruction
                 if (!irs->varsInScope)
-                    irs->varsInScope = new Dsymbols();
+                    irs->varsInScope = new VarDeclarations();
                 irs->varsInScope->push(vd);
             }
         }
@@ -1203,7 +1204,7 @@ elem *Dsymbol_toElem(Dsymbol *s, IRState *irs)
         {
             for (size_t i = 0; i < tm->members->dim; i++)
             {
-                Dsymbol *sm = (Dsymbol *)tm->members->data[i];
+                Dsymbol *sm = tm->members->tdata()[i];
                 e = el_combine(e, Dsymbol_toElem(sm, irs));
             }
         }
@@ -1211,7 +1212,7 @@ elem *Dsymbol_toElem(Dsymbol *s, IRState *irs)
     else if ((td = s->isTupleDeclaration()) != NULL)
     {
         for (size_t i = 0; i < td->objects->dim; i++)
-        {   Object *o = (Object *)td->objects->data[i];
+        {   Object *o = td->objects->tdata()[i];
             if (o->dyncast() == DYNCAST_EXPRESSION)
             {   Expression *eo = (Expression *)o;
                 if (eo->op == TOKdsymbol)
@@ -1807,7 +1808,7 @@ elem *NewExp::toElem(IRState *irs)
         assert(arguments && arguments->dim >= 1);
         if (arguments->dim == 1)
         {   // Single dimension array allocations
-            Expression *arg = (Expression *)arguments->data[0]; // gives array length
+            Expression *arg = arguments->tdata()[0]; // gives array length
             e = arg->toElem(irs);
             d_uns64 elemsize = tda->next->size();
 
@@ -1821,7 +1822,7 @@ elem *NewExp::toElem(IRState *irs)
             e = el_long(TYsize_t, arguments->dim);
             for (size_t i = 0; i < arguments->dim; i++)
             {
-                Expression *arg = (Expression *)arguments->data[i];     // gives array length
+                Expression *arg = arguments->tdata()[i];     // gives array length
                 e = el_param(arg->toElem(irs), e);
                 assert(t->ty == Tarray);
                 t = t->nextOf();
@@ -3537,7 +3538,7 @@ elem *CallExp::toElem(IRState *irs)
         if (fd && fd->ident == Id::alloca &&
             !fd->fbody && fd->linkage == LINKc &&
             arguments && arguments->dim == 1)
-        {   Expression *arg = (Expression *)arguments->data[0];
+        {   Expression *arg = arguments->tdata()[0];
             arg = arg->optimize(WANTvalue);
             if (arg->isConst() && arg->type->isintegral())
             {   dinteger_t sz = arg->toInteger();
@@ -4643,7 +4644,7 @@ elem *TupleExp::toElem(IRState *irs)
 
     //printf("TupleExp::toElem() %s\n", toChars());
     for (size_t i = 0; i < exps->dim; i++)
-    {   Expression *el = (Expression *)exps->data[i];
+    {   Expression *el = exps->tdata()[i];
         elem *ep = el->toElem(irs);
 
         e = el_combine(e, ep);
@@ -4652,11 +4653,11 @@ elem *TupleExp::toElem(IRState *irs)
 }
 
 #if DMDV2
-elem *tree_insert(Expressions *args, int low, int high)
+elem *tree_insert(Elems *args, int low, int high)
 {
     assert(low < high);
     if (low + 1 == high)
-        return (elem *)args->data[low];
+        return args->tdata()[low];
     int mid = (low + high) >> 1;
     return el_param(tree_insert(args, low, mid),
                     tree_insert(args, mid, high));
@@ -4678,7 +4679,7 @@ elem *ArrayLiteralExp::toElem(IRState *irs)
              * Avoids the whole variadic arg mess.
              */
             dim = elements->dim;
-            Expressions args;
+            Elems args;
             args.setDim(dim);           // +1 for number of args parameter
             e = el_long(TYsize_t, dim);
             e = el_param(e, type->getTypeInfo(NULL)->toElem(irs));
@@ -4690,7 +4691,7 @@ elem *ArrayLiteralExp::toElem(IRState *irs)
             targ_size_t sz = tb->nextOf()->size();      // element size
             ::type *te = tb->nextOf()->toCtype();       // element type
             for (size_t i = 0; i < dim; i++)
-            {   Expression *el = (Expression *)elements->data[i];
+            {   Expression *el = elements->tdata()[i];
 
                 /* Generate: *(stmp + i * sz) = element[i]
                  */
@@ -4711,20 +4712,20 @@ elem *ArrayLiteralExp::toElem(IRState *irs)
                     eeq->Ejty = eeq->Ety = TYstruct;
                     eeq->ET = te;
                 }
-                args.data[i] = (void *)eeq;
+                args.tdata()[i] = eeq;
             }
-            e = el_combine(e, el_combines(args.data, dim));
+            e = el_combine(e, el_combines((void **)args.tdata(), dim));
             e = el_combine(e, el_var(stmp));
         }
         else
         {
-            Expressions args;
+            Elems args;
             dim = elements->dim;
             args.setDim(dim + 1);           // +1 for number of args parameter
             e = el_long(TYsize_t, dim);
-            args.data[dim] = (void *)e;
+            args.tdata()[dim] = e;
             for (size_t i = 0; i < dim; i++)
-            {   Expression *el = (Expression *)elements->data[i];
+            {   Expression *el = elements->tdata()[i];
                 elem *ep = el->toElem(irs);
 
                 if (tybasic(ep->Ety) == TYstruct || tybasic(ep->Ety) == TYarray)
@@ -4732,14 +4733,14 @@ elem *ArrayLiteralExp::toElem(IRState *irs)
                     ep = el_una(OPstrpar, TYstruct, ep);
                     ep->ET = el->type->toCtype();
                 }
-                args.data[dim - (i + 1)] = (void *)ep;
+                args.tdata()[dim - (i + 1)] = ep;
             }
 
             /* Because the number of parameters can get very large, produce
              * a balanced binary tree so we don't blow up the stack in
              * the subsequent tree walking code.
              */
-            e = el_params(args.data, dim + 1);
+            e = el_params((void **)args.tdata(), dim + 1);
 
             e = el_param(e, type->getTypeInfo(NULL)->toElem(irs));
 
@@ -4784,13 +4785,13 @@ elem *ExpressionsToStaticArray(IRState *irs, Loc loc, Expressions *exps, Type *t
     symbol *stmp = symbol_genauto(tsarray->toCtype());
     targ_size_t szelem = telem->size();
 
-    Voids elems;
+    Elems elems;
     elems.setDim(dim);
 
     ::type *te = telem->toCtype();      // stmp[] element type
 
     for (size_t i = 0; i < dim; i++)
-    {   Expression *el = (Expression *)exps->data[i];
+    {   Expression *el = exps->tdata()[i];
 
         /* Generate: *(&stmp + i * szelem) = element[i]
          */
@@ -4811,11 +4812,11 @@ elem *ExpressionsToStaticArray(IRState *irs, Loc loc, Expressions *exps, Type *t
             eeq->Ejty = eeq->Ety = TYstruct;
             eeq->ET = te;
         }
-        elems.data[i] = (void *)eeq;
+        elems.tdata()[i] = eeq;
     }
 
     *psym = stmp;
-    return el_combines(elems.data, dim);
+    return el_combines((void **)elems.tdata(), dim);
 }
 
 elem *AssocArrayLiteralExp::toElem(IRState *irs)
@@ -4853,7 +4854,7 @@ elem *AssocArrayLiteralExp::toElem(IRState *irs)
     {    // call _d_assocarrayliteralT(TypeInfo_AssociativeArray ti, size_t length, ...)
         e = el_long(TYsize_t, dim);
         for (size_t i = 0; i < dim; i++)
-        {   Expression *el = (Expression *)keys->data[i];
+        {   Expression *el = keys->tdata()[i];
 
             for (int j = 0; j < 2; j++)
             {
@@ -4867,7 +4868,7 @@ elem *AssocArrayLiteralExp::toElem(IRState *irs)
                 //printf("[%d] %s\n", i, el->toChars());
                 //elem_print(ep);
                 e = el_param(ep, e);
-                el = (Expression *)values->data[i];
+                el = values->tdata()[i];
             }
         }
 
@@ -4967,7 +4968,7 @@ elem *StructLiteralExp::toElem(IRState *irs)
         size_t offset = 0;
         for (size_t i = 0; i < sd->fields.dim; i++)
         {
-            Dsymbol *s = (Dsymbol *)sd->fields.data[i];
+            Dsymbol *s = sd->fields.tdata()[i];
             VarDeclaration *v = s->isVarDeclaration();
             assert(v);
 
@@ -4984,11 +4985,11 @@ elem *StructLiteralExp::toElem(IRState *irs)
         dim = elements->dim;
         assert(dim <= sd->fields.dim);
         for (size_t i = 0; i < dim; i++)
-        {   Expression *el = (Expression *)elements->data[i];
+        {   Expression *el = elements->tdata()[i];
             if (!el)
                 continue;
 
-            Dsymbol *s = (Dsymbol *)sd->fields.data[i];
+            Dsymbol *s = sd->fields.tdata()[i];
             VarDeclaration *v = s->isVarDeclaration();
             assert(v);
             assert(!v->isThisDeclaration());
@@ -5078,7 +5079,7 @@ elem *StructLiteralExp::toElem(IRState *irs)
     if (sd->isnested)
     {   // Initialize the hidden 'this' pointer
         assert(sd->fields.dim);
-        Dsymbol *s = (Dsymbol *)sd->fields.data[sd->fields.dim - 1];
+        Dsymbol *s = sd->fields.tdata()[sd->fields.dim - 1];
         ThisDeclaration *v = s->isThisDeclaration();
         assert(v);
 
@@ -5116,11 +5117,11 @@ elem *appendDtors(IRState *irs, elem *er, size_t starti, size_t endi)
     for (size_t i = endi; i != starti;)
     {
         --i;
-        VarDeclaration *vd = (VarDeclaration *)irs->varsInScope->data[i];
+        VarDeclaration *vd = irs->varsInScope->tdata()[i];
         if (vd)
         {
             //printf("appending dtor\n");
-            irs->varsInScope->data[i] = NULL;
+            irs->varsInScope->tdata()[i] = NULL;
             elem *ed = vd->edtor->toElem(irs);
             edtors = el_combine(edtors, ed);
         }
diff --git a/src/enum.c b/src/enum.c
index 42ad8ecb26cc..ce0ff15478dc 100644
--- a/src/enum.c
+++ b/src/enum.c
@@ -71,7 +71,7 @@ void EnumDeclaration::semantic0(Scope *sc)
         return;
     for (int i = 0; i < members->dim; i++)
     {
-        EnumMember *em = ((Dsymbol *)members->data[i])->isEnumMember();
+        EnumMember *em = (members->tdata()[i])->isEnumMember();
         if (em && (em->type || em->value))
             return;
     }
@@ -165,7 +165,7 @@ void EnumDeclaration::semantic(Scope *sc)
     Expression *elast = NULL;
     for (int i = 0; i < members->dim; i++)
     {
-        EnumMember *em = ((Dsymbol *)members->data[i])->isEnumMember();
+        EnumMember *em = (members->tdata()[i])->isEnumMember();
         Expression *e;
 
         if (!em)
@@ -329,7 +329,7 @@ void EnumDeclaration::toCBuffer(OutBuffer *buf, HdrGenState *hgs)
     buf->writenl();
     for (i = 0; i < members->dim; i++)
     {
-        EnumMember *em = ((Dsymbol *)members->data[i])->isEnumMember();
+        EnumMember *em = (members->tdata()[i])->isEnumMember();
         if (!em)
             continue;
         //buf->writestring("    ");
diff --git a/src/expression.c b/src/expression.c
index 233c06f8f2be..c38784a4084d 100644
--- a/src/expression.c
+++ b/src/expression.c
@@ -249,10 +249,10 @@ Expressions *arrayExpressionSemantic(Expressions *exps, Scope *sc)
     if (exps)
     {
         for (size_t i = 0; i < exps->dim; i++)
-        {   Expression *e = (Expression *)exps->data[i];
+        {   Expression *e = exps->tdata()[i];
             if (e)
             {   e = e->semantic(sc);
-                exps->data[i] = (void *)e;
+                exps->tdata()[i] = e;
             }
         }
     }
@@ -270,7 +270,7 @@ int arrayExpressionCanThrow(Expressions *exps, bool mustNotThrow)
     if (exps)
     {
         for (size_t i = 0; i < exps->dim; i++)
-        {   Expression *e = (Expression *)exps->data[i];
+        {   Expression *e = exps->tdata()[i];
             if (e && e->canThrow(mustNotThrow))
                 return 1;
         }
@@ -289,7 +289,7 @@ void expandTuples(Expressions *exps)
     if (exps)
     {
         for (size_t i = 0; i < exps->dim; i++)
-        {   Expression *arg = (Expression *)exps->data[i];
+        {   Expression *arg = exps->tdata()[i];
             if (!arg)
                 continue;
 
@@ -318,7 +318,7 @@ void expandTuples(Expressions *exps)
                 exps->insert(i, te->exps);      // replace with tuple contents
                 if (i == exps->dim)
                     return;             // empty tuple, no more arguments
-                arg = (Expression *)exps->data[i];
+                arg = exps->tdata()[i];
             }
         }
     }
@@ -331,7 +331,7 @@ Expressions *arrayExpressionToCommonType(Scope *sc, Expressions *exps, Type **pt
      */
     Type *t0 = NULL;
     for (size_t i = 0; i < exps->dim; i++)
-    {   Expression *e = (Expression *)exps->data[i];
+    {   Expression *e = exps->tdata()[i];
 
         if (!e->type)
         {   error("%s has no value", e->toChars());
@@ -343,7 +343,7 @@ Expressions *arrayExpressionToCommonType(Scope *sc, Expressions *exps, Type **pt
             t0 = e->type;
         else
             e = e->implicitCastTo(sc, t0);
-        exps->data[i] = (void *)e;
+        exps->tdata()[i] = e;
     }
 
     if (!t0)
@@ -370,7 +370,7 @@ Expressions *arrayExpressionToCommonType(Scope *sc, Expressions *exps, Type **pt
     Expression *e0;
     int j0;
     for (size_t i = 0; i < exps->dim; i++)
-    {   Expression *e = (Expression *)exps->data[i];
+    {   Expression *e = exps->tdata()[i];
 
         e = resolveProperties(sc, e);
         if (!e->type)
@@ -388,7 +388,7 @@ Expressions *arrayExpressionToCommonType(Scope *sc, Expressions *exps, Type **pt
                 condexp.e1 = e0;
                 condexp.e2 = e;
                 condexp.semantic(sc);
-                exps->data[j0] = (void *)condexp.e1;
+                exps->tdata()[j0] = condexp.e1;
                 e = condexp.e2;
                 j0 = i;
                 e0 = e;
@@ -400,15 +400,15 @@ Expressions *arrayExpressionToCommonType(Scope *sc, Expressions *exps, Type **pt
             e0 = e;
             t0 = e->type;
         }
-        exps->data[i] = (void *)e;
+        exps->tdata()[i] = e;
     }
 
     if (t0)
     {
         for (size_t i = 0; i < exps->dim; i++)
-        {   Expression *e = (Expression *)exps->data[i];
+        {   Expression *e = exps->tdata()[i];
             e = e->implicitCastTo(sc, t0);
-            exps->data[i] = (void *)e;
+            exps->tdata()[i] = e;
         }
     }
     else
@@ -432,7 +432,7 @@ void preFunctionParameters(Loc loc, Scope *sc, Expressions *exps)
         expandTuples(exps);
 
         for (size_t i = 0; i < exps->dim; i++)
-        {   Expression *arg = (Expression *)exps->data[i];
+        {   Expression *arg = exps->tdata()[i];
 
             if (!arg->type)
             {
@@ -445,7 +445,7 @@ void preFunctionParameters(Loc loc, Scope *sc, Expressions *exps)
             }
 
             arg = resolveProperties(sc, arg);
-            exps->data[i] = (void *) arg;
+            exps->tdata()[i] =  arg;
 
             //arg->rvalue();
 #if 0
@@ -453,7 +453,7 @@ void preFunctionParameters(Loc loc, Scope *sc, Expressions *exps)
             {
                 arg = new AddrExp(arg->loc, arg);
                 arg = arg->semantic(sc);
-                exps->data[i] = (void *) arg;
+                exps->tdata()[i] =  arg;
             }
 #endif
         }
@@ -521,7 +521,7 @@ Type *functionParameters(Loc loc, Scope *sc, TypeFunction *tf,
         Expression *arg;
 
         if (i < nargs)
-            arg = (Expression *)arguments->data[i];
+            arg = arguments->tdata()[i];
         else
             arg = NULL;
         Type *tb;
@@ -590,7 +590,7 @@ Type *functionParameters(Loc loc, Scope *sc, TypeFunction *tf,
                         c->type = v->type;
 
                         for (size_t u = i; u < nargs; u++)
-                        {   Expression *a = (Expression *)arguments->data[u];
+                        {   Expression *a = arguments->tdata()[u];
                             if (tret && !((TypeArray *)tb)->next->equals(a->type))
                                 a = a->toDelegate(sc, tret);
 
@@ -614,7 +614,7 @@ Type *functionParameters(Loc loc, Scope *sc, TypeFunction *tf,
                         Expressions *args = new Expressions();
                         args->setDim(nargs - i);
                         for (size_t u = i; u < nargs; u++)
-                            args->data[u - i] = arguments->data[u];
+                            args->tdata()[u - i] = arguments->tdata()[u];
                         arg = new NewExp(loc, NULL, NULL, p->type, args);
                         break;
                     }
@@ -811,7 +811,7 @@ Type *functionParameters(Loc loc, Scope *sc, TypeFunction *tf,
         }
         arg = arg->optimize(WANTvalue);
     L3:
-        arguments->data[i] = (void *) arg;
+        arguments->tdata()[i] =  arg;
         if (done)
             break;
     }
@@ -820,7 +820,7 @@ Type *functionParameters(Loc loc, Scope *sc, TypeFunction *tf,
     if (tf->linkage == LINKd && tf->varargs == 1)
     {
         assert(arguments->dim >= nparams);
-        Expression *e = createTypeInfoArray(sc, (Expression **)&arguments->data[nparams],
+        Expression *e = createTypeInfoArray(sc, (Expression **)&arguments->tdata()[nparams],
                 arguments->dim - nparams);
         arguments->insert(0, e);
     }
@@ -885,7 +885,7 @@ void argsToCBuffer(OutBuffer *buf, Expressions *arguments, HdrGenState *hgs)
     if (arguments)
     {
         for (size_t i = 0; i < arguments->dim; i++)
-        {   Expression *arg = (Expression *)arguments->data[i];
+        {   Expression *arg = arguments->tdata()[i];
 
             if (arg)
             {   if (i)
@@ -906,7 +906,7 @@ void argExpTypesToCBuffer(OutBuffer *buf, Expressions *arguments, HdrGenState *h
     {   OutBuffer argbuf;
 
         for (size_t i = 0; i < arguments->dim; i++)
-        {   Expression *arg = (Expression *)arguments->data[i];
+        {   Expression *arg = arguments->tdata()[i];
 
             if (i)
                 buf->writeByte(',');
@@ -1440,11 +1440,11 @@ Expressions *Expression::arraySyntaxCopy(Expressions *exps)
         a = new Expressions();
         a->setDim(exps->dim);
         for (int i = 0; i < a->dim; i++)
-        {   Expression *e = (Expression *)exps->data[i];
+        {   Expression *e = exps->tdata()[i];
 
             if (e)
                 e = e->syntaxCopy();
-            a->data[i] = e;
+            a->tdata()[i] = e;
         }
     }
     return a;
@@ -3219,7 +3219,7 @@ int ArrayLiteralExp::checkSideEffect(int flag)
 {   int f = 0;
 
     for (size_t i = 0; i < elements->dim; i++)
-    {   Expression *e = (Expression *)elements->data[i];
+    {   Expression *e = elements->tdata()[i];
 
         f |= e->checkSideEffect(2);
     }
@@ -3253,7 +3253,7 @@ void ArrayLiteralExp::toMangleBuffer(OutBuffer *buf)
     size_t dim = elements ? elements->dim : 0;
     buf->printf("A%u", dim);
     for (size_t i = 0; i < dim; i++)
-    {   Expression *e = (Expression *)elements->data[i];
+    {   Expression *e = elements->tdata()[i];
         e->toMangleBuffer(buf);
     }
 }
@@ -3312,8 +3312,8 @@ int AssocArrayLiteralExp::checkSideEffect(int flag)
 {   int f = 0;
 
     for (size_t i = 0; i < keys->dim; i++)
-    {   Expression *key = (Expression *)keys->data[i];
-        Expression *value = (Expression *)values->data[i];
+    {   Expression *key = keys->tdata()[i];
+        Expression *value = values->tdata()[i];
 
         f |= key->checkSideEffect(2);
         f |= value->checkSideEffect(2);
@@ -3340,8 +3340,8 @@ void AssocArrayLiteralExp::toCBuffer(OutBuffer *buf, HdrGenState *hgs)
 {
     buf->writeByte('[');
     for (size_t i = 0; i < keys->dim; i++)
-    {   Expression *key = (Expression *)keys->data[i];
-        Expression *value = (Expression *)values->data[i];
+    {   Expression *key = keys->tdata()[i];
+        Expression *value = values->tdata()[i];
 
         if (i)
             buf->writeByte(',');
@@ -3357,8 +3357,8 @@ void AssocArrayLiteralExp::toMangleBuffer(OutBuffer *buf)
     size_t dim = keys->dim;
     buf->printf("A%u", dim);
     for (size_t i = 0; i < dim; i++)
-    {   Expression *key = (Expression *)keys->data[i];
-        Expression *value = (Expression *)values->data[i];
+    {   Expression *key = keys->tdata()[i];
+        Expression *value = values->tdata()[i];
 
         key->toMangleBuffer(buf);
         value->toMangleBuffer(buf);
@@ -3399,7 +3399,7 @@ Expression *StructLiteralExp::semantic(Scope *sc)
     expandTuples(elements);
     size_t offset = 0;
     for (size_t i = 0; i < elements->dim; i++)
-    {   e = (Expression *)elements->data[i];
+    {   e = elements->tdata()[i];
         if (!e)
             continue;
 
@@ -3412,7 +3412,7 @@ Expression *StructLiteralExp::semantic(Scope *sc)
         {   error("more initializers than fields of %s", sd->toChars());
             return new ErrorExp();
         }
-        Dsymbol *s = (Dsymbol *)sd->fields.data[i];
+        Dsymbol *s = sd->fields.tdata()[i];
         VarDeclaration *v = s->isVarDeclaration();
         assert(v);
         if (v->offset < offset)
@@ -3433,13 +3433,13 @@ Expression *StructLiteralExp::semantic(Scope *sc)
 
         e = e->implicitCastTo(sc, telem);
 
-        elements->data[i] = (void *)e;
+        elements->tdata()[i] = e;
     }
 
     /* Fill out remainder of elements[] with default initializers for fields[]
      */
     for (size_t i = elements->dim; i < nfields; i++)
-    {   Dsymbol *s = (Dsymbol *)sd->fields.data[i];
+    {   Dsymbol *s = sd->fields.tdata()[i];
         VarDeclaration *v = s->isVarDeclaration();
         assert(v);
         assert(!v->isThisDeclaration());
@@ -3511,7 +3511,7 @@ Expression *StructLiteralExp::getField(Type *type, unsigned offset)
     {
         //printf("\ti = %d\n", i);
         assert(i < elements->dim);
-        e = (Expression *)elements->data[i];
+        e = elements->tdata()[i];
         if (e)
         {
             //printf("e = %s, e->type = %s\n", e->toChars(), e->type->toChars());
@@ -3525,7 +3525,7 @@ Expression *StructLiteralExp::getField(Type *type, unsigned offset)
                 Expressions *z = new Expressions;
                 z->setDim(length);
                 for (int q = 0; q < length; ++q)
-                    z->data[q] = e->copy();
+                    z->tdata()[q] = e->copy();
                 e = new ArrayLiteralExp(loc, z);
                 e->type = type;
             }
@@ -3552,13 +3552,13 @@ int StructLiteralExp::getFieldIndex(Type *type, unsigned offset)
     {
         for (size_t i = 0; i < sd->fields.dim; i++)
         {
-            Dsymbol *s = (Dsymbol *)sd->fields.data[i];
+            Dsymbol *s = sd->fields.tdata()[i];
             VarDeclaration *v = s->isVarDeclaration();
             assert(v);
 
             if (offset == v->offset &&
                 type->size() == v->type->size())
-            {   Expression *e = (Expression *)elements->data[i];
+            {   Expression *e = elements->tdata()[i];
                 if (e)
                 {
                     return i;
@@ -3587,7 +3587,7 @@ int StructLiteralExp::checkSideEffect(int flag)
 {   int f = 0;
 
     for (size_t i = 0; i < elements->dim; i++)
-    {   Expression *e = (Expression *)elements->data[i];
+    {   Expression *e = elements->tdata()[i];
         if (!e)
             continue;
 
@@ -3618,7 +3618,7 @@ void StructLiteralExp::toMangleBuffer(OutBuffer *buf)
     size_t dim = elements ? elements->dim : 0;
     buf->printf("S%u", dim);
     for (size_t i = 0; i < dim; i++)
-    {   Expression *e = (Expression *)elements->data[i];
+    {   Expression *e = elements->tdata()[i];
         if (e)
             e->toMangleBuffer(buf);
         else
@@ -3867,7 +3867,7 @@ Expression *NewExp::semantic(Scope *sc)
         else if (cd->isAbstract())
         {   error("cannot create instance of abstract class %s", cd->toChars());
             for (int i = 0; i < cd->vtbl.dim; i++)
-            {   FuncDeclaration *fd = ((Dsymbol *)cd->vtbl.data[i])->isFuncDeclaration();
+            {   FuncDeclaration *fd = cd->vtbl.tdata()[i]->isFuncDeclaration();
                 if (fd && fd->isAbstract())
                     error("function %s is abstract", fd->toChars());
             }
@@ -4097,7 +4097,7 @@ Expression *NewExp::semantic(Scope *sc)
                 goto Lerr;
             }
 
-            Expression *arg = (Expression *)arguments->data[i];
+            Expression *arg = arguments->tdata()[i];
             arg = resolveProperties(sc, arg);
             arg = arg->implicitCastTo(sc, Type::tsize_t);
             arg = arg->optimize(WANTvalue);
@@ -4105,7 +4105,7 @@ Expression *NewExp::semantic(Scope *sc)
             {   error("negative array index %s", arg->toChars());
                 goto Lerr;
             }
-            arguments->data[i] = (void *) arg;
+            arguments->tdata()[i] =  arg;
             tb = ((TypeDArray *)tb)->next->toBasetype();
         }
     }
@@ -4585,7 +4585,7 @@ TupleExp::TupleExp(Loc loc, TupleDeclaration *tup)
 
     exps->reserve(tup->objects->dim);
     for (size_t i = 0; i < tup->objects->dim; i++)
-    {   Object *o = (Object *)tup->objects->data[i];
+    {   Object *o = tup->objects->tdata()[i];
         if (o->dyncast() == DYNCAST_EXPRESSION)
         {
             Expression *e = (Expression *)o;
@@ -4623,8 +4623,8 @@ int TupleExp::equals(Object *o)
         if (exps->dim != te->exps->dim)
             return 0;
         for (size_t i = 0; i < exps->dim; i++)
-        {   Expression *e1 = (Expression *)exps->data[i];
-            Expression *e2 = (Expression *)te->exps->data[i];
+        {   Expression *e1 = exps->tdata()[i];
+            Expression *e2 = te->exps->tdata()[i];
 
             if (!e1->equals(e2))
                 return 0;
@@ -4649,20 +4649,20 @@ Expression *TupleExp::semantic(Scope *sc)
 
     // Run semantic() on each argument
     for (size_t i = 0; i < exps->dim; i++)
-    {   Expression *e = (Expression *)exps->data[i];
+    {   Expression *e = exps->tdata()[i];
 
         e = e->semantic(sc);
         if (!e->type)
         {   error("%s has no value", e->toChars());
             e = new ErrorExp();
         }
-        exps->data[i] = (void *)e;
+        exps->tdata()[i] = e;
     }
 
     expandTuples(exps);
     if (0 && exps->dim == 1)
     {
-        return (Expression *)exps->data[0];
+        return exps->tdata()[0];
     }
     type = new TypeTuple(exps);
     type = type->semantic(loc, sc);
@@ -4681,7 +4681,7 @@ int TupleExp::checkSideEffect(int flag)
 {   int f = 0;
 
     for (int i = 0; i < exps->dim; i++)
-    {   Expression *e = (Expression *)exps->data[i];
+    {   Expression *e = exps->tdata()[i];
 
         f |= e->checkSideEffect(2);
     }
@@ -4700,7 +4700,7 @@ int TupleExp::canThrow(bool mustNotThrow)
 void TupleExp::checkEscape()
 {
     for (size_t i = 0; i < exps->dim; i++)
-    {   Expression *e = (Expression *)exps->data[i];
+    {   Expression *e = exps->tdata()[i];
         e->checkEscape();
     }
 }
@@ -4807,7 +4807,7 @@ Expression *DeclarationExp::semantic(Scope *sc)
     if (ad)
     {
         if (ad->decl && ad->decl->dim == 1)
-            s = (Dsymbol *)ad->decl->data[0];
+            s = ad->decl->tdata()[0];
     }
 
     if (s->isVarDeclaration())
@@ -5010,7 +5010,7 @@ void TraitsExp::toCBuffer(OutBuffer *buf, HdrGenState *hgs)
         for (int i = 0; i < args->dim; i++)
         {
             buf->writeByte(',');
-            Object *oarg = (Object *)args->data[i];
+            Object *oarg = args->tdata()[i];
             ObjectToCBuffer(buf, hgs, oarg);
         }
     }
@@ -5067,8 +5067,8 @@ Expression *IsExp::syntaxCopy()
         p = new TemplateParameters();
         p->setDim(parameters->dim);
         for (int i = 0; i < p->dim; i++)
-        {   TemplateParameter *tp = (TemplateParameter *)parameters->data[i];
-            p->data[i] = (void *)tp->syntaxCopy();
+        {   TemplateParameter *tp = parameters->tdata()[i];
+            p->tdata()[i] = tp->syntaxCopy();
         }
     }
 
@@ -5178,7 +5178,7 @@ Expression *IsExp::semantic(Scope *sc)
                     Parameters *args = new Parameters;
                     args->reserve(cd->baseclasses->dim);
                     for (size_t i = 0; i < cd->baseclasses->dim; i++)
-                    {   BaseClass *b = (BaseClass *)cd->baseclasses->data[i];
+                    {   BaseClass *b = cd->baseclasses->tdata()[i];
                         args->push(new Parameter(STCin, b->type, NULL, NULL));
                     }
                     tded = new TypeTuple(args);
@@ -5275,18 +5275,18 @@ Expression *IsExp::semantic(Scope *sc)
         }
         else
         {
-            tded = (Type *)dedtypes.data[0];
+            tded = (Type *)dedtypes.tdata()[0];
             if (!tded)
                 tded = targ;
 #if DMDV2
             Objects tiargs;
             tiargs.setDim(1);
-            tiargs.data[0] = (void *)targ;
+            tiargs.tdata()[0] = targ;
 
             /* Declare trailing parameters
              */
             for (int i = 1; i < parameters->dim; i++)
-            {   TemplateParameter *tp = (TemplateParameter *)parameters->data[i];
+            {   TemplateParameter *tp = parameters->tdata()[i];
                 Declaration *s = NULL;
 
                 m = tp->matchArg(sc, &tiargs, i, parameters, &dedtypes, &s);
@@ -5294,7 +5294,7 @@ Expression *IsExp::semantic(Scope *sc)
                     goto Lno;
                 s->semantic(sc);
 #if 0
-                Object *o = (Object *)dedtypes.data[i];
+                Type *o = dedtypes.tdata()[i];
                 Dsymbol *s = TemplateDeclaration::declareParameter(loc, sc, tp, o);
 #endif
                 if (sc->sd)
@@ -5379,7 +5379,7 @@ void IsExp::toCBuffer(OutBuffer *buf, HdrGenState *hgs)
         for (int i = 1; i < parameters->dim; i++)
         {
             buf->writeByte(',');
-            TemplateParameter *tp = (TemplateParameter *)parameters->data[i];
+            TemplateParameter *tp = parameters->tdata()[i];
             tp->toCBuffer(buf, hgs);
         }
     }
@@ -6010,10 +6010,10 @@ Expression *DotIdExp::semantic(Scope *sc, int flag)
         Expressions *exps = new Expressions();
         exps->setDim(te->exps->dim);
         for (int i = 0; i < exps->dim; i++)
-        {   Expression *e = (Expression *)te->exps->data[i];
+        {   Expression *e = te->exps->tdata()[i];
             e = e->semantic(sc);
             e = new DotIdExp(e->loc, e, Id::offsetof);
-            exps->data[i] = (void *)e;
+            exps->tdata()[i] = e;
         }
         e = new TupleExp(loc, exps);
         e = e->semantic(sc);
@@ -6280,7 +6280,7 @@ Expression *DotVarExp::semantic(Scope *sc)
 
             exps->reserve(tup->objects->dim);
             for (size_t i = 0; i < tup->objects->dim; i++)
-            {   Object *o = (Object *)tup->objects->data[i];
+            {   Object *o = tup->objects->tdata()[i];
                 if (o->dyncast() != DYNCAST_EXPRESSION)
                 {
                     error("%s is not an expression", o->toChars());
@@ -6648,7 +6648,7 @@ CallExp::CallExp(Loc loc, Expression *e, Expression *earg1)
     Expressions *arguments = new Expressions();
     if (earg1)
     {   arguments->setDim(1);
-        arguments->data[0] = (void *)earg1;
+        arguments->tdata()[0] = earg1;
     }
     this->arguments = arguments;
 }
@@ -6658,8 +6658,8 @@ CallExp::CallExp(Loc loc, Expression *e, Expression *earg1, Expression *earg2)
 {
     Expressions *arguments = new Expressions();
     arguments->setDim(2);
-    arguments->data[0] = (void *)earg1;
-    arguments->data[1] = (void *)earg2;
+    arguments->tdata()[0] = earg1;
+    arguments->tdata()[1] = earg2;
 
     this->arguments = arguments;
 }
@@ -6688,7 +6688,7 @@ Expression *CallExp::semantic(Scope *sc)
 #if 0
     if (arguments && arguments->dim)
     {
-        Expression *earg = (Expression *)arguments->data[0];
+        Expression *earg = arguments->tdata()[0];
         earg->print();
         if (earg->type) earg->type->print();
     }
@@ -6721,7 +6721,7 @@ Expression *CallExp::semantic(Scope *sc)
                 {   error("expected key as argument to aa.remove()");
                     return new ErrorExp();
                 }
-                Expression *key = (Expression *)arguments->data[0];
+                Expression *key = arguments->tdata()[0];
                 key = key->semantic(sc);
                 key = resolveProperties(sc, key);
                 key->rvalue();
@@ -6984,7 +6984,7 @@ Expression *CallExp::semantic(Scope *sc)
     if (arguments && arguments->dim)
     {
         for (int k = 0; k < arguments->dim; k++)
-        {   Expression *checkarg = (Expression *)arguments->data[k];
+        {   Expression *checkarg = arguments->tdata()[k];
             if (checkarg->op == TOKerror)
                 return checkarg;
         }
@@ -7213,7 +7213,7 @@ Expression *CallExp::semantic(Scope *sc)
         FuncDeclaration *f = NULL;
         Dsymbol *s = NULL;
         for (int i = 0; i < eo->vars->a.dim; i++)
-        {   s = (Dsymbol *)eo->vars->a.data[i];
+        {   s = eo->vars->a.tdata()[i];
             FuncDeclaration *f2 = s->isFuncDeclaration();
             if (f2)
             {
@@ -7381,7 +7381,7 @@ int CallExp::checkSideEffect(int flag)
     /* If any of the arguments have side effects, this expression does
      */
     for (size_t i = 0; i < arguments->dim; i++)
-    {   Expression *e = (Expression *)arguments->data[i];
+    {   Expression *e = arguments->tdata()[i];
 
         if (e->checkSideEffect(2))
             return 1;
@@ -7409,7 +7409,7 @@ int CallExp::canThrow(bool mustNotThrow)
     /* If any of the arguments can throw, then this expression can throw
      */
     for (size_t i = 0; i < arguments->dim; i++)
-    {   Expression *e = (Expression *)arguments->data[i];
+    {   Expression *e = arguments->tdata()[i];
 
         if (e && e->canThrow(mustNotThrow))
             return 1;
@@ -8323,8 +8323,8 @@ Expression *SliceExp::semantic(Scope *sc)
             {   Expressions *exps = new Expressions;
                 exps->setDim(j2 - j1);
                 for (size_t i = 0; i < j2 - j1; i++)
-                {   Expression *e = (Expression *)te->exps->data[j1 + i];
-                    exps->data[i] = (void *)e;
+                {   Expression *e = te->exps->tdata()[j1 + i];
+                    exps->tdata()[i] = e;
                 }
                 e = new TupleExp(loc, exps);
             }
@@ -8534,13 +8534,13 @@ Expression *ArrayExp::semantic(Scope *sc)
         {   error("only one index allowed to index %s", t1->toChars());
             goto Lerr;
         }
-        e = new IndexExp(loc, e1, (Expression *)arguments->data[0]);
+        e = new IndexExp(loc, e1, arguments->tdata()[0]);
         return e->semantic(sc);
     }
 
     // Run semantic() on each argument
     for (size_t i = 0; i < arguments->dim; i++)
-    {   e = (Expression *)arguments->data[i];
+    {   e = arguments->tdata()[i];
 
         e = e->semantic(sc);
         if (!e->type)
@@ -8549,7 +8549,7 @@ Expression *ArrayExp::semantic(Scope *sc)
         }
         else if (e->type == Type::terror)
             goto Lerr;
-        arguments->data[i] = (void *)e;
+        arguments->tdata()[i] = e;
     }
 
     expandTuples(arguments);
@@ -8835,7 +8835,7 @@ Expression *IndexExp::semantic(Scope *sc)
             {
 
                 if (e1->op == TOKtuple)
-                    e = (Expression *)te->exps->data[(size_t)index];
+                    e = te->exps->tdata()[(size_t)index];
                 else
                     e = new TypeExp(e1->loc, Parameter::getNth(tup->arguments, (size_t)index)->type);
             }
@@ -9089,7 +9089,7 @@ Expression *AssignExp::semantic(Scope *sc)
                         return new ErrorExp();
                     }
 
-                    e = new CallExp(loc, e, (Expression *)ae->arguments->data[0], e2);
+                    e = new CallExp(loc, e, ae->arguments->tdata()[0], e2);
                     e = e->semantic(sc);
                     return e;
                 }
@@ -9168,9 +9168,9 @@ Expression *AssignExp::semantic(Scope *sc)
             exps->setDim(dim);
 
             for (int i = 0; i < dim; i++)
-            {   Expression *ex1 = (Expression *)tup1->exps->data[i];
-                Expression *ex2 = (Expression *)tup2->exps->data[i];
-                exps->data[i] = (void *) new AssignExp(loc, ex1, ex2);
+            {   Expression *ex1 = tup1->exps->tdata()[i];
+                Expression *ex2 = tup2->exps->tdata()[i];
+                exps->tdata()[i] =  new AssignExp(loc, ex1, ex2);
             }
             Expression *e = new TupleExp(loc, exps);
             e = e->semantic(sc);
@@ -10589,7 +10589,7 @@ Expression *PowExp::semantic(Scope *sc)
         {
             importMathChecked = 1;
             for (int i = 0; i < Module::amodules.dim; i++)
-            {   Module *mi = (Module *)Module::amodules.data[i];
+            {   Module *mi = Module::amodules.tdata()[i];
                 //printf("\t[%d] %s\n", i, mi->toChars());
                 if (mi->ident == Id::math &&
                     mi->parent->ident == Id::std &&
diff --git a/src/func.c b/src/func.c
index 5df99990c7c5..79daf6433f4c 100644
--- a/src/func.c
+++ b/src/func.c
@@ -453,7 +453,7 @@ void FuncDeclaration::semantic(Scope *sc)
                 return;
 
             default:
-            {   FuncDeclaration *fdv = (FuncDeclaration *)cd->baseClass->vtbl.data[vi];
+            {   FuncDeclaration *fdv = (FuncDeclaration *)cd->baseClass->vtbl.tdata()[vi];
                 // This function is covariant with fdv
                 if (fdv->isFinal())
                     error("cannot override final function %s", fdv->toPrettyChars());
@@ -480,7 +480,7 @@ void FuncDeclaration::semantic(Scope *sc)
                         )
                         error("multiple overrides of same function");
                 }
-                cd->vtbl.data[vi] = (void *)this;
+                cd->vtbl.tdata()[vi] = this;
                 vtblIndex = vi;
 
                 /* Remember which functions this overrides
@@ -531,7 +531,7 @@ void FuncDeclaration::semantic(Scope *sc)
                     return;
 
                 default:
-                {   FuncDeclaration *fdv = (FuncDeclaration *)b->base->vtbl.data[vi];
+                {   FuncDeclaration *fdv = (FuncDeclaration *)b->base->vtbl.tdata()[vi];
                     Type *ti = NULL;
 
                     /* Remember which functions this overrides
@@ -809,7 +809,7 @@ void FuncDeclaration::semantic3(Scope *sc)
     {
         for (int i = 0; i < fthrows->dim; i++)
         {
-            Type *t = (Type *)fthrows->data[i];
+            Type *t = fthrows->tdata()[i];
 
             t = t->semantic(loc, sc);
             if (!t->isClassHandle())
@@ -991,7 +991,7 @@ void FuncDeclaration::semantic3(Scope *sc)
         if (f->parameters)
         {
             for (size_t i = 0; i < f->parameters->dim; i++)
-            {   Parameter *arg = (Parameter *)f->parameters->data[i];
+            {   Parameter *arg = f->parameters->tdata()[i];
 
                 //printf("[%d] arg->type->ty = %d %s\n", i, arg->type->ty, arg->type->toChars());
                 if (arg->type->ty == Ttuple)
@@ -1014,7 +1014,7 @@ void FuncDeclaration::semantic3(Scope *sc)
         {   /* parameters[] has all the tuples removed, as the back end
              * doesn't know about tuples
              */
-            parameters = new Dsymbols();
+            parameters = new VarDeclarations();
             parameters->reserve(nparams);
             for (size_t i = 0; i < nparams; i++)
             {
@@ -1051,7 +1051,7 @@ void FuncDeclaration::semantic3(Scope *sc)
         if (f->parameters)
         {
             for (size_t i = 0; i < f->parameters->dim; i++)
-            {   Parameter *arg = (Parameter *)f->parameters->data[i];
+            {   Parameter *arg = f->parameters->tdata()[i];
 
                 if (!arg->ident)
                     continue;                   // never used, so ignore
@@ -1066,7 +1066,7 @@ void FuncDeclaration::semantic3(Scope *sc)
                         VarDeclaration *v = sc2->search(0, narg->ident, NULL)->isVarDeclaration();
                         assert(v);
                         Expression *e = new VarExp(v->loc, v);
-                        exps->data[j] = (void *)e;
+                        exps->tdata()[j] = e;
                     }
                     assert(arg->ident);
                     TupleDeclaration *v = new TupleDeclaration(loc, arg->ident, exps);
@@ -1228,7 +1228,7 @@ void FuncDeclaration::semantic3(Scope *sc)
             if (isCtorDeclaration() && cd)
             {
                 for (int i = 0; i < cd->fields.dim; i++)
-                {   VarDeclaration *v = (VarDeclaration *)cd->fields.data[i];
+                {   VarDeclaration *v = cd->fields.tdata()[i];
 
                     v->ctorinit = 0;
                 }
@@ -1265,7 +1265,7 @@ void FuncDeclaration::semantic3(Scope *sc)
                 else
                 {
                     for (int i = 0; i < ad->members->dim; i++)
-                    {   Dsymbol *s = (Dsymbol *)ad->members->data[i];
+                    {   Dsymbol *s = ad->members->tdata()[i];
 
                         s->checkCtorConstInit();
                     }
@@ -1280,7 +1280,7 @@ void FuncDeclaration::semantic3(Scope *sc)
                 if (!(sc2->callSuper & CSXthis_ctor))
                 {
                     for (int i = 0; i < cd->fields.dim; i++)
-                    {   VarDeclaration *v = (VarDeclaration *)cd->fields.data[i];
+                    {   VarDeclaration *v = cd->fields.tdata()[i];
 
                         if (v->ctorinit == 0 && v->isCtorinit() && !v->type->isMutable())
                             error("missing initializer for final field %s", v->toChars());
@@ -1372,7 +1372,7 @@ void FuncDeclaration::semantic3(Scope *sc)
             if (parameters)
             {   for (size_t i = 0; i < parameters->dim; i++)
                 {
-                    VarDeclaration *v = (VarDeclaration *)parameters->data[i];
+                    VarDeclaration *v = parameters->tdata()[i];
                     if (v->storage_class & STCout)
                     {
                         assert(v->init);
@@ -1412,7 +1412,7 @@ void FuncDeclaration::semantic3(Scope *sc)
                     if (parameters && parameters->dim)
                     {
                         int lastNonref = parameters->dim -1;
-                        p = (VarDeclaration *)parameters->data[lastNonref];
+                        p = parameters->tdata()[lastNonref];
                         /* The trouble with out and ref parameters is that taking
                          * the address of it doesn't work, because later processing
                          * adds in an extra level of indirection. So we skip over them.
@@ -1426,7 +1426,7 @@ void FuncDeclaration::semantic3(Scope *sc)
                                 p = v_arguments;
                                 break;
                             }
-                            p = (VarDeclaration *)parameters->data[lastNonref];
+                            p = parameters->tdata()[lastNonref];
                         }
                     }
                     else
@@ -1545,7 +1545,7 @@ void FuncDeclaration::semantic3(Scope *sc)
             if (parameters)
             {   for (size_t i = 0; i < parameters->dim; i++)
                 {
-                    VarDeclaration *v = (VarDeclaration *)parameters->data[i];
+                    VarDeclaration *v = parameters->tdata()[i];
 
                     if (v->storage_class & (STCref | STCout))
                         continue;
@@ -1722,7 +1722,7 @@ Statement *FuncDeclaration::mergeFrequire(Statement *sf)
      */
     for (int i = 0; i < foverrides.dim; i++)
     {
-        FuncDeclaration *fdv = (FuncDeclaration *)foverrides.data[i];
+        FuncDeclaration *fdv = foverrides.tdata()[i];
 
         /* The semantic pass on the contracts of the overridden functions must
          * be completed before code generation occurs (bug 3602).
@@ -1779,7 +1779,7 @@ Statement *FuncDeclaration::mergeFensure(Statement *sf)
      */
     for (int i = 0; i < foverrides.dim; i++)
     {
-        FuncDeclaration *fdv = (FuncDeclaration *)foverrides.data[i];
+        FuncDeclaration *fdv = foverrides.tdata()[i];
 
         /* The semantic pass on the contracts of the overridden functions must
          * be completed before code generation occurs (bug 3602 and 5230).
@@ -1846,13 +1846,13 @@ int FuncDeclaration::overrides(FuncDeclaration *fd)
  *      -2      can't determine because of forward references
  */
 
-int FuncDeclaration::findVtblIndex(FuncDeclarations *vtbl, int dim)
+int FuncDeclaration::findVtblIndex(Dsymbols *vtbl, int dim)
 {
     FuncDeclaration *mismatch = NULL;
     int bestvi = -1;
     for (int vi = 0; vi < dim; vi++)
     {
-        FuncDeclaration *fdv = ((Dsymbol *)vtbl->data[vi])->isFuncDeclaration();
+        FuncDeclaration *fdv = vtbl->tdata()[vi]->isFuncDeclaration();
         if (fdv && fdv->ident == ident)
         {
             if (type->equals(fdv->type))        // if exact match
@@ -2195,7 +2195,7 @@ if (arguments)
     for (i = 0; i < arguments->dim; i++)
     {   Expression *arg;
 
-        arg = (Expression *)arguments->data[i];
+        arg = arguments->tdata()[i];
         assert(arg->type);
         printf("\t%s: ", arg->toChars());
         arg->type->print();
@@ -2238,7 +2238,7 @@ if (arguments)
             OutBuffer buf2;
             tf->modToBuffer(&buf2);
 
-            //printf("tf = %s, args = %s\n", tf->deco, ((Expression *)arguments->data[0])->type->deco);
+            //printf("tf = %s, args = %s\n", tf->deco, arguments->tdata()[0]->type->deco);
             error(loc, "%s%s is not callable using argument types %s",
                 Parameter::argsTypesToChars(tf->parameters, tf->varargs),
                 buf2.toChars(),
@@ -2324,7 +2324,7 @@ MATCH FuncDeclaration::leastAsSpecialized(FuncDeclaration *g)
         }
         else
             e = p->type->defaultInit();
-        args.data[u] = e;
+        args.tdata()[u] = e;
     }
 
     MATCH m = (MATCH) tg->callMatch(NULL, &args, 1);
@@ -2767,12 +2767,12 @@ int FuncDeclaration::needsClosure()
 
     //printf("FuncDeclaration::needsClosure() %s\n", toChars());
     for (int i = 0; i < closureVars.dim; i++)
-    {   VarDeclaration *v = (VarDeclaration *)closureVars.data[i];
+    {   VarDeclaration *v = closureVars.tdata()[i];
         assert(v->isVarDeclaration());
         //printf("\tv = %s\n", v->toChars());
 
         for (int j = 0; j < v->nestedrefs.dim; j++)
-        {   FuncDeclaration *f = (FuncDeclaration *)v->nestedrefs.data[j];
+        {   FuncDeclaration *f = v->nestedrefs.tdata()[j];
             assert(f != this);
 
             //printf("\t\tf = %s, %d, %p, %d\n", f->toChars(), f->isVirtual(), f->isThis(), f->tookAddressOf);
diff --git a/src/glue.c b/src/glue.c
index 44b22a151b3b..f592a9aeb7be 100644
--- a/src/glue.c
+++ b/src/glue.c
@@ -80,7 +80,7 @@ void obj_append(Dsymbol *s)
 void obj_write_deferred(Library *library)
 {
     for (int i = 0; i < obj_symbols_towrite.dim; i++)
-    {   Dsymbol *s = (Dsymbol *)obj_symbols_towrite.data[i];
+    {   Dsymbol *s = obj_symbols_towrite.tdata()[i];
         Module *m = s->getModule();
 
         char *mname;
@@ -227,7 +227,7 @@ void Module::genobjfile(int multiobj)
         /* Generate a reference to the moduleinfo, so the module constructors
          * and destructors get linked in.
          */
-        Module *m = (Module *)aimports.data[0];
+        Module *m = aimports.tdata()[0];
         assert(m);
         if (m->sictor || m->sctor || m->sdtor || m->ssharedctor || m->sshareddtor)
         {
@@ -275,7 +275,7 @@ void Module::genobjfile(int multiobj)
 
     for (int i = 0; i < members->dim; i++)
     {
-        Dsymbol *member = (Dsymbol *)members->data[i];
+        Dsymbol *member = members->tdata()[i];
         member->toObjFile(multiobj);
     }
 
@@ -361,7 +361,7 @@ void Module::genobjfile(int multiobj)
             cstate.CSpsymtab = &sctor->Sfunc->Flocsym;
 
             for (int i = 0; i < ectorgates.dim; i++)
-            {   StaticDtorDeclaration *f = (StaticDtorDeclaration *)ectorgates.data[i];
+            {   StaticDtorDeclaration *f = ectorgates.tdata()[i];
 
                 Symbol *s = f->vgate->toSymbol();
                 elem *e = el_var(s);
@@ -402,7 +402,7 @@ void Module::genobjfile(int multiobj)
             cstate.CSpsymtab = &ssharedctor->Sfunc->Flocsym;
 
             for (int i = 0; i < esharedctorgates.dim; i++)
-            {   SharedStaticDtorDeclaration *f = (SharedStaticDtorDeclaration *)esharedctorgates.data[i];
+            {   SharedStaticDtorDeclaration *f = esharedctorgates.tdata()[i];
 
                 Symbol *s = f->vgate->toSymbol();
                 elem *e = el_var(s);
@@ -737,7 +737,7 @@ void FuncDeclaration::toObjFile(int multiobj)
     if (parameters)
     {
         for (i = 0; i < parameters->dim; i++)
-        {   VarDeclaration *v = (VarDeclaration *)parameters->data[i];
+        {   VarDeclaration *v = parameters->tdata()[i];
             if (v->csym)
             {
                 error("compiler error, parameter '%s', bugzilla 2962?", v->toChars());
@@ -1023,7 +1023,7 @@ void FuncDeclaration::toObjFile(int multiobj)
 
     for (i = 0; i < irs.deferToObj->dim; i++)
     {
-        Dsymbol *s = (Dsymbol *)irs.deferToObj->data[i];
+        Dsymbol *s = irs.deferToObj->tdata()[i];
         s->toObjFile(0);
     }
 
diff --git a/src/hdrgen.c b/src/hdrgen.c
index 512cb0b805a9..80e357413815 100644
--- a/src/hdrgen.c
+++ b/src/hdrgen.c
@@ -86,7 +86,7 @@ void Module::toCBuffer(OutBuffer *buf, HdrGenState *hgs)
     }
 
     for (int i = 0; i < members->dim; i++)
-    {   Dsymbol *s = (Dsymbol *)members->data[i];
+    {   Dsymbol *s = members->tdata()[i];
 
         s->toHBuffer(buf, hgs);
     }
diff --git a/src/iasm.c b/src/iasm.c
index 1844a50ec6d8..b036662491a9 100644
--- a/src/iasm.c
+++ b/src/iasm.c
@@ -2004,7 +2004,7 @@ STATIC OPND *asm_merge_opnds(OPND *o1, OPND *o2)
                 error(asmstate.loc, "tuple index %u exceeds length %u", index, tup->objects->dim);
             else
             {
-                Object *o = (Object *)tup->objects->data[index];
+                Object *o = tup->objects->tdata()[index];
                 if (o->dyncast() == DYNCAST_DSYMBOL)
                 {   o1->s = (Dsymbol *)o;
                     return o1;
diff --git a/src/import.c b/src/import.c
index 41f1d0b1b363..0bda649912fd 100644
--- a/src/import.c
+++ b/src/import.c
@@ -42,7 +42,7 @@ Import::Import(Loc loc, Identifiers *packages, Identifier *id, Identifier *alias
         this->ident = aliasId;
     // Kludge to change Import identifier to first package
     else if (packages && packages->dim)
-        this->ident = (Identifier *)packages->data[0];
+        this->ident = packages->tdata()[0];
 }
 
 void Import::addAlias(Identifier *name, Identifier *alias)
@@ -73,7 +73,7 @@ Dsymbol *Import::syntaxCopy(Dsymbol *s)
 
     for (size_t i = 0; i < names.dim; i++)
     {
-        si->addAlias((Identifier *)names.data[i], (Identifier *)aliases.data[i]);
+        si->addAlias(names.tdata()[i], aliases.tdata()[i]);
     }
 
     return si;
@@ -198,11 +198,11 @@ void Import::semantic(Scope *sc)
 
         sc = sc->push(mod);
         for (size_t i = 0; i < aliasdecls.dim; i++)
-        {   Dsymbol *s = (Dsymbol *)aliasdecls.data[i];
+        {   Dsymbol *s = aliasdecls.tdata()[i];
 
             //printf("\tImport alias semantic('%s')\n", s->toChars());
-            if (!mod->search(loc, (Identifier *)names.data[i], 0))
-                error("%s not found", ((Identifier *)names.data[i])->toChars());
+            if (!mod->search(loc, names.tdata()[i], 0))
+                error("%s not found", (names.tdata()[i])->toChars());
 
             s->semantic(sc);
         }
@@ -240,7 +240,7 @@ void Import::semantic(Scope *sc)
         {
             for (size_t i = 0; i < packages->dim; i++)
             {
-                Identifier *pid = (Identifier *)packages->data[i];
+                Identifier *pid = packages->tdata()[i];
                 ob->printf("%s.", pid->toChars());
             }
         }
@@ -260,8 +260,8 @@ void Import::semantic(Scope *sc)
             else
                 ob->writebyte(',');
 
-            Identifier *name = (Identifier *)names.data[i];
-            Identifier *alias = (Identifier *)aliases.data[i];
+            Identifier *name = names.tdata()[i];
+            Identifier *alias = aliases.tdata()[i];
 
             if (!alias)
             {
@@ -317,8 +317,8 @@ int Import::addMember(Scope *sc, ScopeDsymbol *sd, int memnum)
      */
     for (size_t i = 0; i < names.dim; i++)
     {
-        Identifier *name = (Identifier *)names.data[i];
-        Identifier *alias = (Identifier *)aliases.data[i];
+        Identifier *name = names.tdata()[i];
+        Identifier *alias = aliases.tdata()[i];
 
         if (!alias)
             alias = name;
@@ -367,7 +367,7 @@ void Import::toCBuffer(OutBuffer *buf, HdrGenState *hgs)
     if (packages && packages->dim)
     {
         for (size_t i = 0; i < packages->dim; i++)
-        {   Identifier *pid = (Identifier *)packages->data[i];
+        {   Identifier *pid = packages->tdata()[i];
 
             buf->printf("%s.", pid->toChars());
         }
diff --git a/src/init.c b/src/init.c
index 3b81f27bd85a..6f1fa75e93d7 100644
--- a/src/init.c
+++ b/src/init.c
@@ -53,10 +53,10 @@ Initializers *Initializer::arraySyntaxCopy(Initializers *ai)
         a = new Initializers();
         a->setDim(ai->dim);
         for (int i = 0; i < a->dim; i++)
-        {   Initializer *e = (Initializer *)ai->data[i];
+        {   Initializer *e = ai->tdata()[i];
 
             e = e->syntaxCopy();
-            a->data[i] = e;
+            a->tdata()[i] = e;
         }
     }
     return a;
@@ -125,11 +125,11 @@ Initializer *StructInitializer::syntaxCopy()
     ai->value.setDim(value.dim);
     for (int i = 0; i < field.dim; i++)
     {
-        ai->field.data[i] = field.data[i];
+        ai->field.tdata()[i] = field.tdata()[i];
 
-        Initializer *init = (Initializer *)value.data[i];
+        Initializer *init = value.tdata()[i];
         init = init->syntaxCopy();
-        ai->value.data[i] = init;
+        ai->value.tdata()[i] = init;
     }
     return ai;
 }
@@ -159,8 +159,8 @@ Initializer *StructInitializer::semantic(Scope *sc, Type *t, int needInterpret)
                 ad->kind(), ad->toChars(), ad->toChars());
         for (size_t i = 0; i < field.dim; i++)
         {
-            Identifier *id = (Identifier *)field.data[i];
-            Initializer *val = (Initializer *)value.data[i];
+            Identifier *id = field.tdata()[i];
+            Initializer *val = value.tdata()[i];
             Dsymbol *s;
             VarDeclaration *v;
 
@@ -175,7 +175,7 @@ Initializer *StructInitializer::semantic(Scope *sc, Type *t, int needInterpret)
                 }
                 else
                 {
-                    s = (Dsymbol *)ad->fields.data[fieldi];
+                    s = ad->fields.tdata()[fieldi];
                 }
             }
             else
@@ -199,15 +199,15 @@ Initializer *StructInitializer::semantic(Scope *sc, Type *t, int needInterpret)
                         errors = 1;
                         break;
                     }
-                    if (s == (Dsymbol *)ad->fields.data[fieldi])
+                    if (s == ad->fields.tdata()[fieldi])
                         break;
                 }
             }
             if (s && (v = s->isVarDeclaration()) != NULL)
             {
                 val = val->semantic(sc, v->type, needInterpret);
-                value.data[i] = (void *)val;
-                vars.data[i] = (void *)v;
+                value.tdata()[i] = val;
+                vars.tdata()[i] = v;
             }
             else
             {   error(loc, "%s is not a field of %s", id ? id->toChars() : s->toChars(), ad->toChars());
@@ -263,12 +263,12 @@ Expression *StructInitializer::toExpression()
     elements->setDim(ad->fields.dim);
     for (int i = 0; i < elements->dim; i++)
     {
-        elements->data[i] = NULL;
+        elements->tdata()[i] = NULL;
     }
     unsigned fieldi = 0;
     for (int i = 0; i < value.dim; i++)
     {
-        Identifier *id = (Identifier *)field.data[i];
+        Identifier *id = field.tdata()[i];
         if (id)
         {
             Dsymbol * s = ad->search(loc, id, 0);
@@ -286,7 +286,7 @@ Expression *StructInitializer::toExpression()
                     s->error("is not a per-instance initializable field");
                     goto Lno;
                 }
-                if (s == (Dsymbol *)ad->fields.data[fieldi])
+                if (s == ad->fields.tdata()[fieldi])
                     break;
             }
         }
@@ -294,18 +294,18 @@ Expression *StructInitializer::toExpression()
         {   error(loc, "too many initializers for '%s'", ad->toChars());
             goto Lno;
         }
-        Initializer *iz = (Initializer *)value.data[i];
+        Initializer *iz = value.tdata()[i];
         if (!iz)
             goto Lno;
         Expression *ex = iz->toExpression();
         if (!ex)
             goto Lno;
-        if (elements->data[fieldi])
+        if (elements->tdata()[fieldi])
         {   error(loc, "duplicate initializer for field '%s'",
-                ((Dsymbol *)ad->fields.data[fieldi])->toChars());
+                ad->fields.tdata()[fieldi]->toChars());
             goto Lno;
         }
-        elements->data[fieldi] = ex;
+        elements->tdata()[fieldi] = ex;
         ++fieldi;
     }
     // Now, fill in any missing elements with default initializers.
@@ -313,20 +313,20 @@ Expression *StructInitializer::toExpression()
     offset = 0;
     for (int i = 0; i < elements->dim; )
     {
-        VarDeclaration * vd = ((Dsymbol *)ad->fields.data[i])->isVarDeclaration();
+        VarDeclaration * vd = ad->fields.tdata()[i]->isVarDeclaration();
 
         //printf("test2 [%d] : %s %d %d\n", i, vd->toChars(), (int)offset, (int)vd->offset);
         if (vd->offset < offset)
         {
             // Only the first field of a union can have an initializer
-            if (elements->data[i])
+            if (elements->tdata()[i])
                 goto Lno;
         }
         else
         {
-            if (!elements->data[i])
+            if (!elements->tdata()[i])
                 // Default initialize
-                elements->data[i] = vd->type->defaultInit();
+                elements->tdata()[i] = vd->type->defaultInit();
         }
         offset = vd->offset + vd->type->size();
         i++;
@@ -334,15 +334,15 @@ Expression *StructInitializer::toExpression()
         int unionSize = ad->numFieldsInUnion(i);
         if (unionSize == 1)
         {   // Not a union -- default initialize if missing
-            if (!elements->data[i])
-                elements->data[i] = vd->type->defaultInit();
+            if (!elements->tdata()[i])
+                elements->tdata()[i] = vd->type->defaultInit();
         }
         else
         {   // anonymous union -- check for errors
             int found = -1; // index of the first field with an initializer
             for (int j = i; j < i + unionSize; ++j)
             {
-                if (!elements->data[j])
+                if (!elements->tdata()[j])
                     continue;
                 if (found >= 0)
                 {
@@ -383,13 +383,13 @@ void StructInitializer::toCBuffer(OutBuffer *buf, HdrGenState *hgs)
     {
         if (i > 0)
             buf->writebyte(',');
-        Identifier *id = (Identifier *)field.data[i];
+        Identifier *id = field.tdata()[i];
         if (id)
         {
             buf->writestring(id->toChars());
             buf->writebyte(':');
         }
-        Initializer *iz = (Initializer *)value.data[i];
+        Initializer *iz = value.tdata()[i];
         if (iz)
             iz->toCBuffer(buf, hgs);
     }
@@ -416,14 +416,14 @@ Initializer *ArrayInitializer::syntaxCopy()
     ai->index.setDim(index.dim);
     ai->value.setDim(value.dim);
     for (int i = 0; i < ai->value.dim; i++)
-    {   Expression *e = (Expression *)index.data[i];
+    {   Expression *e = index.tdata()[i];
         if (e)
             e = e->syntaxCopy();
-        ai->index.data[i] = e;
+        ai->index.tdata()[i] = e;
 
-        Initializer *init = (Initializer *)value.data[i];
+        Initializer *init = value.tdata()[i];
         init = init->syntaxCopy();
-        ai->value.data[i] = init;
+        ai->value.tdata()[i] = init;
     }
     return ai;
 }
@@ -462,17 +462,17 @@ Initializer *ArrayInitializer::semantic(Scope *sc, Type *t, int needInterpret)
     length = 0;
     for (i = 0; i < index.dim; i++)
     {
-        Expression *idx = (Expression *)index.data[i];
+        Expression *idx = index.tdata()[i];
         if (idx)
         {   idx = idx->semantic(sc);
             idx = idx->optimize(WANTvalue | WANTinterpret);
-            index.data[i] = (void *)idx;
+            index.tdata()[i] = idx;
             length = idx->toInteger();
         }
 
-        Initializer *val = (Initializer *)value.data[i];
+        Initializer *val = value.tdata()[i];
         val = val->semantic(sc, t->nextOf(), needInterpret);
-        value.data[i] = (void *)val;
+        value.tdata()[i] = val;
         length++;
         if (length == 0)
         {   error(loc, "array dimension overflow");
@@ -541,8 +541,8 @@ Expression *ArrayInitializer::toExpression()
         edim = value.dim;
         for (size_t i = 0, j = 0; i < value.dim; i++, j++)
         {
-            if (index.data[i])
-                j = ((Expression *)index.data[i])->toInteger();
+            if (index.tdata()[i])
+                j = index.tdata()[i]->toInteger();
             if (j >= edim)
                 edim = j + 1;
         }
@@ -553,10 +553,10 @@ Expression *ArrayInitializer::toExpression()
     elements->zero();
     for (size_t i = 0, j = 0; i < value.dim; i++, j++)
     {
-        if (index.data[i])
-            j = ((Expression *)index.data[i])->toInteger();
+        if (index.tdata()[i])
+            j = (index.tdata()[i])->toInteger();
         assert(j < edim);
-        Initializer *iz = (Initializer *)value.data[i];
+        Initializer *iz = value.tdata()[i];
         if (!iz)
             goto Lno;
         Expression *ex = iz->toExpression();
@@ -564,7 +564,7 @@ Expression *ArrayInitializer::toExpression()
         {
             goto Lno;
         }
-        elements->data[j] = ex;
+        elements->tdata()[j] = ex;
     }
 
     /* Fill in any missing elements with the default initializer
@@ -573,13 +573,13 @@ Expression *ArrayInitializer::toExpression()
     Expression *init = NULL;
     for (size_t i = 0; i < edim; i++)
     {
-        if (!elements->data[i])
+        if (!elements->tdata()[i])
         {
             if (!type)
                 goto Lno;
             if (!init)
                 init = ((TypeNext *)t)->next->defaultInit();
-            elements->data[i] = init;
+            elements->tdata()[i] = init;
         }
     }
 
@@ -610,18 +610,18 @@ Expression *ArrayInitializer::toAssocArrayLiteral()
 
     for (size_t i = 0; i < value.dim; i++)
     {
-        e = (Expression *)index.data[i];
+        e = index.tdata()[i];
         if (!e)
             goto Lno;
-        keys->data[i] = (void *)e;
+        keys->tdata()[i] = e;
 
-        Initializer *iz = (Initializer *)value.data[i];
+        Initializer *iz = value.tdata()[i];
         if (!iz)
             goto Lno;
         e = iz->toExpression();
         if (!e)
             goto Lno;
-        values->data[i] = (void *)e;
+        values->tdata()[i] = e;
     }
     e = new AssocArrayLiteralExp(loc, keys, values);
     return e;
@@ -637,7 +637,7 @@ int ArrayInitializer::isAssociativeArray()
 {
     for (size_t i = 0; i < value.dim; i++)
     {
-        if (index.data[i])
+        if (index.tdata()[i])
             return 1;
     }
     return 0;
@@ -699,13 +699,13 @@ void ArrayInitializer::toCBuffer(OutBuffer *buf, HdrGenState *hgs)
     {
         if (i > 0)
             buf->writebyte(',');
-        Expression *ex = (Expression *)index.data[i];
+        Expression *ex = index.tdata()[i];
         if (ex)
         {
             ex->toCBuffer(buf, hgs);
             buf->writebyte(':');
         }
-        Initializer *iz = (Initializer *)value.data[i];
+        Initializer *iz = value.tdata()[i];
         if (iz)
             iz->toCBuffer(buf, hgs);
     }
diff --git a/src/inline.c b/src/inline.c
index 7dc31b78f7cd..36e1d2427776 100644
--- a/src/inline.c
+++ b/src/inline.c
@@ -54,7 +54,7 @@ int CompoundStatement::inlineCost(InlineCostState *ics)
 {   int cost = 0;
 
     for (size_t i = 0; i < statements->dim; i++)
-    {   Statement *s = (Statement *) statements->data[i];
+    {   Statement *s =  statements->tdata()[i];
         if (s)
         {
             cost += s->inlineCost(ics);
@@ -69,7 +69,7 @@ int UnrolledLoopStatement::inlineCost(InlineCostState *ics)
 {   int cost = 0;
 
     for (size_t i = 0; i < statements->dim; i++)
-    {   Statement *s = (Statement *) statements->data[i];
+    {   Statement *s =  statements->tdata()[i];
         if (s)
         {
             cost += s->inlineCost(ics);
@@ -136,7 +136,7 @@ int arrayInlineCost(InlineCostState *ics, Expressions *arguments)
     if (arguments)
     {
         for (int i = 0; i < arguments->dim; i++)
-        {   Expression *e = (Expression *)arguments->data[i];
+        {   Expression *e = arguments->tdata()[i];
 
             if (e)
                 cost += e->inlineCost(ics);
@@ -226,7 +226,7 @@ int DeclarationExp::inlineCost(InlineCostState *ics)
             return COST_MAX;    // finish DeclarationExp::doInline
 #else
             for (size_t i = 0; i < td->objects->dim; i++)
-            {   Object *o = (Object *)td->objects->data[i];
+            {   Object *o = td->objects->tdata()[i];
                 if (o->dyncast() != DYNCAST_EXPRESSION)
                     return COST_MAX;
                 Expression *eo = (Expression *)o;
@@ -355,7 +355,7 @@ Expression *CompoundStatement::doInline(InlineDoState *ids)
 
     //printf("CompoundStatement::doInline() %d\n", statements->dim);
     for (size_t i = 0; i < statements->dim; i++)
-    {   Statement *s = (Statement *) statements->data[i];
+    {   Statement *s =  statements->tdata()[i];
         if (s)
         {
             Expression *e2 = s->doInline(ids);
@@ -387,7 +387,7 @@ Expression *UnrolledLoopStatement::doInline(InlineDoState *ids)
 
     //printf("UnrolledLoopStatement::doInline() %d\n", statements->dim);
     for (size_t i = 0; i < statements->dim; i++)
-    {   Statement *s = (Statement *) statements->data[i];
+    {   Statement *s =  statements->tdata()[i];
         if (s)
         {
             Expression *e2 = s->doInline(ids);
@@ -460,11 +460,11 @@ Expressions *arrayExpressiondoInline(Expressions *a, InlineDoState *ids)
         newa->setDim(a->dim);
 
         for (int i = 0; i < a->dim; i++)
-        {   Expression *e = (Expression *)a->data[i];
+        {   Expression *e = a->tdata()[i];
 
             if (e)
                 e = e->doInline(ids);
-            newa->data[i] = (void *)e;
+            newa->tdata()[i] = e;
         }
     }
     return newa;
@@ -483,11 +483,11 @@ Expression *SymOffExp::doInline(InlineDoState *ids)
     //printf("SymOffExp::doInline(%s)\n", toChars());
     for (i = 0; i < ids->from.dim; i++)
     {
-        if (var == (Declaration *)ids->from.data[i])
+        if (var == ids->from.tdata()[i])
         {
             SymOffExp *se = (SymOffExp *)copy();
 
-            se->var = (Declaration *)ids->to.data[i];
+            se->var = (Declaration *)ids->to.tdata()[i];
             return se;
         }
     }
@@ -501,11 +501,11 @@ Expression *VarExp::doInline(InlineDoState *ids)
     //printf("VarExp::doInline(%s)\n", toChars());
     for (i = 0; i < ids->from.dim; i++)
     {
-        if (var == (Declaration *)ids->from.data[i])
+        if (var == ids->from.tdata()[i])
         {
             VarExp *ve = (VarExp *)copy();
 
-            ve->var = (Declaration *)ids->to.data[i];
+            ve->var = (Declaration *)ids->to.tdata()[i];
             return ve;
         }
     }
@@ -549,7 +549,7 @@ Expression *DeclarationExp::doInline(InlineDoState *ids)
         if (td)
         {
             for (size_t i = 0; i < td->objects->dim; i++)
-            {   DsymbolExp *se = (DsymbolExp *)td->objects->data[i];
+            {   DsymbolExp *se = td->objects->tdata()[i];
                 assert(se->op == TOKdsymbol);
                 se->s;
             }
@@ -812,9 +812,9 @@ Statement *ExpStatement::inlineScan(InlineScanState *iss)
 Statement *CompoundStatement::inlineScan(InlineScanState *iss)
 {
     for (size_t i = 0; i < statements->dim; i++)
-    {   Statement *s = (Statement *) statements->data[i];
+    {   Statement *s =  statements->tdata()[i];
         if (s)
-            statements->data[i] = (void *)s->inlineScan(iss);
+            statements->tdata()[i] = s->inlineScan(iss);
     }
     return this;
 }
@@ -822,9 +822,9 @@ Statement *CompoundStatement::inlineScan(InlineScanState *iss)
 Statement *UnrolledLoopStatement::inlineScan(InlineScanState *iss)
 {
     for (size_t i = 0; i < statements->dim; i++)
-    {   Statement *s = (Statement *) statements->data[i];
+    {   Statement *s =  statements->tdata()[i];
         if (s)
-            statements->data[i] = (void *)s->inlineScan(iss);
+            statements->tdata()[i] = s->inlineScan(iss);
     }
     return this;
 }
@@ -908,10 +908,10 @@ Statement *SwitchStatement::inlineScan(InlineScanState *iss)
     if (cases)
     {
         for (int i = 0; i < cases->dim; i++)
-        {   Statement *s;
+        {   CaseStatement *s;
 
-            s = (Statement *) cases->data[i];
-            cases->data[i] = (void *)s->inlineScan(iss);
+            s =  cases->tdata()[i];
+            cases->tdata()[i] = (CaseStatement *)s->inlineScan(iss);
         }
     }
     return this;
@@ -974,7 +974,7 @@ Statement *TryCatchStatement::inlineScan(InlineScanState *iss)
     if (catches)
     {
         for (int i = 0; i < catches->dim; i++)
-        {   Catch *c = (Catch *)catches->data[i];
+        {   Catch *c = catches->tdata()[i];
 
             if (c->handler)
                 c->handler = c->handler->inlineScan(iss);
@@ -1024,12 +1024,12 @@ void arrayInlineScan(InlineScanState *iss, Expressions *arguments)
     if (arguments)
     {
         for (int i = 0; i < arguments->dim; i++)
-        {   Expression *e = (Expression *)arguments->data[i];
+        {   Expression *e = arguments->tdata()[i];
 
             if (e)
             {
                 e = e->inlineScan(iss);
-                arguments->data[i] = (void *)e;
+                arguments->tdata()[i] = e;
             }
         }
     }
@@ -1049,7 +1049,7 @@ void scanVar(Dsymbol *s, InlineScanState *iss)
         if (td)
         {
             for (size_t i = 0; i < td->objects->dim; i++)
-            {   DsymbolExp *se = (DsymbolExp *)td->objects->data[i];
+            {   DsymbolExp *se = (DsymbolExp *)td->objects->tdata()[i];
                 assert(se->op == TOKdsymbol);
                 scanVar(se->s, iss);
             }
@@ -1352,7 +1352,7 @@ int FuncDeclaration::canInline(int hasthis, int hdrscan)
     {
         for (int i = 0; i < parameters->dim; i++)
         {
-            VarDeclaration *v = (VarDeclaration *)parameters->data[i];
+            VarDeclaration *v = parameters->tdata()[i];
             if (
 #if DMDV1
                 v->isOut() || v->isRef() ||
@@ -1470,9 +1470,9 @@ Expression *FuncDeclaration::doInline(InlineScanState *iss, Expression *ethis, E
 
         for (int i = 0; i < arguments->dim; i++)
         {
-            VarDeclaration *vfrom = (VarDeclaration *)parameters->data[i];
+            VarDeclaration *vfrom = parameters->tdata()[i];
             VarDeclaration *vto;
-            Expression *arg = (Expression *)arguments->data[i];
+            Expression *arg = arguments->tdata()[i];
             ExpInitializer *ei;
             VarExp *ve;
 
diff --git a/src/interpret.c b/src/interpret.c
index 1a164d41aa44..f69f257b5270 100644
--- a/src/interpret.c
+++ b/src/interpret.c
@@ -30,7 +30,7 @@ struct InterState
 {
     InterState *caller;         // calling function's InterState
     FuncDeclaration *fd;        // function being interpreted
-    Dsymbols vars;              // variables used in this function
+    VarDeclarations vars;              // variables used in this function
     Statement *start;           // if !=NULL, start execution at this statement
     Statement *gotoTarget;      // target of EXP_GOTO_INTERPRET result
     Expression *localThis;      // value of 'this', or NULL if none
@@ -149,7 +149,7 @@ Expression *FuncDeclaration::interpret(InterState *istate, Expressions *argument
         eargs.setDim(dim);
 
         for (size_t i = 0; i < dim; i++)
-        {   Expression *earg = (Expression *)arguments->data[i];
+        {   Expression *earg = arguments->tdata()[i];
             Parameter *arg = Parameter::getNth(tf->parameters, i);
 
             if (arg->storageClass & (STCout | STCref))
@@ -180,14 +180,14 @@ Expression *FuncDeclaration::interpret(InterState *istate, Expressions *argument
                     return NULL;
                 }
             }
-            eargs.data[i] = earg;
+            eargs.tdata()[i] = earg;
         }
 
         for (size_t i = 0; i < dim; i++)
-        {   Expression *earg = (Expression *)eargs.data[i];
+        {   Expression *earg = eargs.tdata()[i];
             Parameter *arg = Parameter::getNth(tf->parameters, i);
-            VarDeclaration *v = (VarDeclaration *)parameters->data[i];
-            vsave.data[i] = v->getValue();
+            VarDeclaration *v = parameters->tdata()[i];
+            vsave.tdata()[i] = v->getValue();
 #if LOG
             printf("arg[%d] = %s\n", i, earg->toChars());
 #endif
@@ -204,9 +204,9 @@ Expression *FuncDeclaration::interpret(InterState *istate, Expressions *argument
                  */
                 assert(istate);
                 for (size_t i = 0; i < istate->vars.dim; i++)
-                {   VarDeclaration *vx = (VarDeclaration *)istate->vars.data[i];
+                {   VarDeclaration *vx = istate->vars.tdata()[i];
                     if (vx == v2)
-                    {   istate->vars.data[i] = NULL;
+                    {   istate->vars.tdata()[i] = NULL;
                         break;
                     }
                 }
@@ -227,9 +227,9 @@ Expression *FuncDeclaration::interpret(InterState *istate, Expressions *argument
         if (!thisvar) // it's a reference. Find which variable it refers to.
             thisvar = findParentVar(thisarg->interpret(istate), istate->localThis);
         for (size_t i = 0; i < istate->vars.dim; i++)
-        {   VarDeclaration *v = (VarDeclaration *)istate->vars.data[i];
+        {   VarDeclaration *v = istate->vars.tdata()[i];
             if (v == thisvar)
-            {   istate->vars.data[i] = NULL;
+            {   istate->vars.tdata()[i] = NULL;
                 break;
             }
         }
@@ -243,11 +243,11 @@ Expression *FuncDeclaration::interpret(InterState *istate, Expressions *argument
         //printf("saving local variables...\n");
         valueSaves.setDim(istate->vars.dim);
         for (size_t i = 0; i < istate->vars.dim; i++)
-        {   VarDeclaration *v = (VarDeclaration *)istate->vars.data[i];
+        {   VarDeclaration *v = istate->vars.tdata()[i];
             if (v)
             {
                 //printf("\tsaving [%d] %s = %s\n", i, v->toChars(), v->value ? v->value->toChars() : "");
-                valueSaves.data[i] = v->getValue();
+                valueSaves.tdata()[i] = v->getValue();
                 v->setValueNull();
             }
         }
@@ -284,8 +284,8 @@ Expression *FuncDeclaration::interpret(InterState *istate, Expressions *argument
      */
     for (size_t i = 0; i < dim; i++)
     {
-        VarDeclaration *v = (VarDeclaration *)parameters->data[i];
-        v->setValueWithoutChecking((Expression *)vsave.data[i]);
+        VarDeclaration *v = parameters->tdata()[i];
+        v->setValueWithoutChecking(vsave.tdata()[i]);
     }
 
     if (istate && !isNested())
@@ -294,9 +294,9 @@ Expression *FuncDeclaration::interpret(InterState *istate, Expressions *argument
          */
         //printf("restoring local variables...\n");
         for (size_t i = 0; i < istate->vars.dim; i++)
-        {   VarDeclaration *v = (VarDeclaration *)istate->vars.data[i];
+        {   VarDeclaration *v = istate->vars.tdata()[i];
             if (v)
-            {   v->setValueWithoutChecking((Expression *)valueSaves.data[i]);
+            {   v->setValueWithoutChecking(valueSaves.tdata()[i]);
                 //printf("\trestoring [%d] %s = %s\n", i, v->toChars(), v->getValue() ? v->getValue()->toChars() : "");
             }
         }
@@ -360,7 +360,7 @@ Expression *CompoundStatement::interpret(InterState *istate)
     if (statements)
     {
         for (size_t i = 0; i < statements->dim; i++)
-        {   Statement *s = (Statement *)statements->data[i];
+        {   Statement *s = statements->tdata()[i];
 
             if (s)
             {
@@ -387,7 +387,7 @@ Expression *UnrolledLoopStatement::interpret(InterState *istate)
     if (statements)
     {
         for (size_t i = 0; i < statements->dim; i++)
-        {   Statement *s = (Statement *)statements->data[i];
+        {   Statement *s = statements->tdata()[i];
 
             e = s->interpret(istate);
             if (e == EXP_CANT_INTERPRET)
@@ -976,7 +976,7 @@ Expression *SwitchStatement::interpret(InterState *istate)
     {
         for (size_t i = 0; i < cases->dim; i++)
         {
-            CaseStatement *cs = (CaseStatement *)cases->data[i];
+            CaseStatement *cs = cases->tdata()[i];
             e = Equal(TOKequal, Type::tint32, econdition, cs->exp);
             if (e == EXP_CANT_INTERPRET)
                 return EXP_CANT_INTERPRET;
@@ -1455,7 +1455,7 @@ Expression *TupleExp::interpret(InterState *istate, CtfeGoal goal)
     Expressions *expsx = NULL;
 
     for (size_t i = 0; i < exps->dim; i++)
-    {   Expression *e = (Expression *)exps->data[i];
+    {   Expression *e = exps->tdata()[i];
         Expression *ex;
 
         ex = e->interpret(istate);
@@ -1473,10 +1473,10 @@ Expression *TupleExp::interpret(InterState *istate, CtfeGoal goal)
                 expsx->setDim(exps->dim);
                 for (size_t j = 0; j < i; j++)
                 {
-                    expsx->data[j] = exps->data[j];
+                    expsx->tdata()[j] = exps->tdata()[j];
                 }
             }
-            expsx->data[i] = (void *)ex;
+            expsx->tdata()[i] = ex;
         }
     }
     if (expsx)
@@ -1497,7 +1497,7 @@ Expression *ArrayLiteralExp::interpret(InterState *istate, CtfeGoal goal)
     if (elements)
     {
         for (size_t i = 0; i < elements->dim; i++)
-        {   Expression *e = (Expression *)elements->data[i];
+        {   Expression *e = elements->tdata()[i];
             Expression *ex;
 
             ex = e->interpret(istate);
@@ -1513,10 +1513,10 @@ Expression *ArrayLiteralExp::interpret(InterState *istate, CtfeGoal goal)
                     expsx->setDim(elements->dim);
                     for (size_t j = 0; j < elements->dim; j++)
                     {
-                        expsx->data[j] = elements->data[j];
+                        expsx->tdata()[j] = elements->tdata()[j];
                     }
                 }
-                expsx->data[i] = (void *)ex;
+                expsx->tdata()[i] = ex;
             }
         }
     }
@@ -1546,8 +1546,8 @@ Expression *AssocArrayLiteralExp::interpret(InterState *istate, CtfeGoal goal)
     printf("AssocArrayLiteralExp::interpret() %s\n", toChars());
 #endif
     for (size_t i = 0; i < keys->dim; i++)
-    {   Expression *ekey = (Expression *)keys->data[i];
-        Expression *evalue = (Expression *)values->data[i];
+    {   Expression *ekey = keys->tdata()[i];
+        Expression *evalue = values->tdata()[i];
         Expression *ex;
 
         ex = ekey->interpret(istate);
@@ -1560,7 +1560,7 @@ Expression *AssocArrayLiteralExp::interpret(InterState *istate, CtfeGoal goal)
         {
             if (keysx == keys)
                 keysx = (Expressions *)keys->copy();
-            keysx->data[i] = (void *)ex;
+            keysx->tdata()[i] = ex;
         }
 
         ex = evalue->interpret(istate);
@@ -1573,7 +1573,7 @@ Expression *AssocArrayLiteralExp::interpret(InterState *istate, CtfeGoal goal)
         {
             if (valuesx == values)
                 valuesx = (Expressions *)values->copy();
-            valuesx->data[i] = (void *)ex;
+            valuesx->tdata()[i] = ex;
         }
     }
     if (keysx != keys)
@@ -1586,10 +1586,10 @@ Expression *AssocArrayLiteralExp::interpret(InterState *istate, CtfeGoal goal)
     /* Remove duplicate keys
      */
     for (size_t i = 1; i < keysx->dim; i++)
-    {   Expression *ekey = (Expression *)keysx->data[i - 1];
+    {   Expression *ekey = keysx->tdata()[i - 1];
 
         for (size_t j = i; j < keysx->dim; j++)
-        {   Expression *ekey2 = (Expression *)keysx->data[j];
+        {   Expression *ekey2 = keysx->tdata()[j];
             Expression *ex = Equal(TOKequal, Type::tbool, ekey, ekey2);
             if (ex == EXP_CANT_INTERPRET)
                 goto Lerr;
@@ -1641,7 +1641,7 @@ Expression *StructLiteralExp::interpret(InterState *istate, CtfeGoal goal)
     if (elements)
     {
         for (size_t i = 0; i < elements->dim; i++)
-        {   Expression *e = (Expression *)elements->data[i];
+        {   Expression *e = elements->tdata()[i];
             if (!e)
                 continue;
 
@@ -1660,10 +1660,10 @@ Expression *StructLiteralExp::interpret(InterState *istate, CtfeGoal goal)
                     expsx->setDim(elements->dim);
                     for (size_t j = 0; j < elements->dim; j++)
                     {
-                        expsx->data[j] = elements->data[j];
+                        expsx->tdata()[j] = elements->tdata()[j];
                     }
                 }
-                expsx->data[i] = (void *)ex;
+                expsx->tdata()[i] = ex;
             }
         }
     }
@@ -1691,7 +1691,7 @@ ArrayLiteralExp *createBlockDuplicatedArrayLiteral(Type *type,
     Expressions *elements = new Expressions();
     elements->setDim(dim);
     for (size_t i = 0; i < dim; i++)
-         elements->data[i] = elem;
+         elements->tdata()[i] = elem;
     ArrayLiteralExp *ae = new ArrayLiteralExp(0, elements);
     ae->type = type;
     return ae;
@@ -1728,7 +1728,7 @@ Expression *NewExp::interpret(InterState *istate, CtfeGoal goal)
 #endif
     if (newtype->ty == Tarray && arguments && arguments->dim == 1)
     {
-        Expression *lenExpr = ((Expression *)(arguments->data[0]))->interpret(istate);
+        Expression *lenExpr = ((arguments->tdata()[0]))->interpret(istate);
         if (lenExpr == EXP_CANT_INTERPRET)
             return EXP_CANT_INTERPRET;
         return createBlockDuplicatedArrayLiteral(newtype,
@@ -1883,16 +1883,16 @@ BIN_INTERPRET2(Cmp)
 /***************************************
  * Duplicate the elements array, then set field 'indexToChange' = newelem.
  */
-Expressions *changeOneElement(Expressions *oldelems, size_t indexToChange, void *newelem)
+Expressions *changeOneElement(Expressions *oldelems, size_t indexToChange, Expression *newelem)
 {
     Expressions *expsx = new Expressions();
     expsx->setDim(oldelems->dim);
     for (size_t j = 0; j < expsx->dim; j++)
     {
         if (j == indexToChange)
-            expsx->data[j] = newelem;
+            expsx->tdata()[j] = newelem;
         else
-            expsx->data[j] = oldelems->data[j];
+            expsx->tdata()[j] = oldelems->tdata()[j];
     }
     return expsx;
 }
@@ -1911,7 +1911,7 @@ void addVarToInterstate(InterState *istate, VarDeclaration *v)
                 //printf("\tadding %s to istate\n", v->toChars());
                 break;
             }
-            if (v == (VarDeclaration *)istate->vars.data[i])
+            if (v == istate->vars.tdata()[i])
                 break;
         }
     }
@@ -1945,12 +1945,12 @@ Expression *assignAssocArrayElement(Loc loc, AssocArrayLiteralExp *aae, Expressi
     int updated = 0;
     for (size_t j = valuesx->dim; j; )
     {   j--;
-        Expression *ekey = (Expression *)aae->keys->data[j];
+        Expression *ekey = aae->keys->tdata()[j];
         Expression *ex = Equal(TOKequal, Type::tbool, ekey, index);
         if (ex == EXP_CANT_INTERPRET)
             return EXP_CANT_INTERPRET;
         if (ex->isBool(TRUE))
-        {   valuesx->data[j] = (void *)newval;
+        {   valuesx->tdata()[j] = newval;
             updated = 1;
         }
     }
@@ -2091,7 +2091,7 @@ Expression *assignDotVar(ExpressionReverseIterator rvs, int depth, Expression *e
         if (fieldi == -1)
             return EXP_CANT_INTERPRET;
         assert(fieldi>=0 && fieldi < se->elements->dim);
-        Expression *ex =  (Expression *)(se->elements->data[fieldi]);
+        Expression *ex =  (se->elements->tdata()[fieldi]);
 
         newval = assignDotVar(rvs, depth - 1, ex, newval);
         Expressions *expsx = changeOneElement(se->elements, fieldi, newval);
@@ -2170,7 +2170,7 @@ Expression *copyLiteral(Expression *e)
         Expressions *newelems = new Expressions();
         newelems->setDim(oldelems->dim);
         for (size_t i = 0; i < oldelems->dim; i++)
-            newelems->data[i] = copyLiteral((Expression *)(oldelems->data[i]));
+            newelems->tdata()[i] = copyLiteral((oldelems->tdata()[i]));
         ArrayLiteralExp *r = new ArrayLiteralExp(ae->loc, newelems);
         r->type = e->type;
         return r;
@@ -2187,10 +2187,10 @@ Expression *copyLiteral(Expression *e)
         newelems->setDim(oldelems->dim);
         for (size_t i = 0; i < newelems->dim; i++)
         {
-            Expression *m = (Expression *)oldelems->data[i];
+            Expression *m = oldelems->tdata()[i];
             // We need the struct definition to detect block assignment
             StructDeclaration *sd = se->sd;
-            Dsymbol *s = (Dsymbol *)sd->fields.data[i];
+            Dsymbol *s = sd->fields.tdata()[i];
             VarDeclaration *v = s->isVarDeclaration();
             assert(v);
             if ((v->type->ty != m->type->ty) && v->type->ty == Tsarray)
@@ -2201,7 +2201,7 @@ Expression *copyLiteral(Expression *e)
 
                 m = createBlockDuplicatedArrayLiteral(v->type, m, length);
             } else m = copyLiteral(m);
-            newelems->data[i] = m;
+            newelems->tdata()[i] = m;
         }
 #if DMDV2
         StructLiteralExp *r = new StructLiteralExp(e->loc, se->sd, newelems, se->stype);
@@ -2229,11 +2229,11 @@ void recursiveBlockAssign(ArrayLiteralExp *ae, Expression *val)
 #endif
     for (size_t k = 0; k < ae->elements->dim; k++)
     {
-        if (!directblk && ((Expression *)(ae->elements->data[k]))->op == TOKarrayliteral)
+        if (!directblk && ae->elements->tdata()[k]->op == TOKarrayliteral)
         {
-            recursiveBlockAssign((ArrayLiteralExp *)(ae->elements->data[k]), val);
+            recursiveBlockAssign((ArrayLiteralExp *)ae->elements->tdata()[k], val);
         }
-        else ae->elements->data[k] = val;
+        else ae->elements->tdata()[k] = val;
     }
 }
 
@@ -2421,10 +2421,10 @@ Expression *BinExp::interpretAssignCommon(InterState *istate, CtfeGoal goal, fp_
                 size_t copylen = oldlen < newlen ? oldlen : newlen;
                 ArrayLiteralExp *ae = (ArrayLiteralExp *)oldval;
                 for (size_t i = 0; i < copylen; i++)
-                     elements->data[i] = ae->elements->data[i];
+                     elements->tdata()[i] = ae->elements->tdata()[i];
 
                 for (size_t i = copylen; i < newlen; i++)
-                    elements->data[i] = defaultElem;
+                    elements->tdata()[i] = defaultElem;
                 ArrayLiteralExp *aae = new ArrayLiteralExp(0, elements);
                 aae->type = t;
                 newval = aae;
@@ -2703,7 +2703,7 @@ Expression *BinExp::interpretAssignCommon(InterState *istate, CtfeGoal goal, fp_
                 return EXP_CANT_INTERPRET;
             }
             int se_indx = se3->getFieldIndex(e1->type, vv->offset);
-            se3->elements->data[se_indx] = newval;
+            se3->elements->tdata()[se_indx] = newval;
             // Mark the parent variable as modified
             if (!destinationIsReference)
                 addVarToInterstate(istate, ultimateVar);
@@ -2865,7 +2865,7 @@ Expression *BinExp::interpretAssignCommon(InterState *istate, CtfeGoal goal, fp_
         }
         if (existingAE)
         {
-            existingAE->elements->data[indexToModify] = newval;
+            existingAE->elements->tdata()[indexToModify] = newval;
             return e;
         }
         if (existingSE)
@@ -2998,7 +2998,7 @@ Expression *BinExp::interpretAssignCommon(InterState *istate, CtfeGoal goal, fp_
             Expressions *newelems = ((ArrayLiteralExp *)newval)->elements;
             for (size_t j = 0; j < newelems->dim; j++)
             {
-                oldelems->data[j + firstIndex] = newelems->data[j];
+                oldelems->tdata()[j + firstIndex] = newelems->tdata()[j];
             }
             return newval;
         }
@@ -3031,7 +3031,7 @@ Expression *BinExp::interpretAssignCommon(InterState *istate, CtfeGoal goal, fp_
                         assert(0);
                         break;
                 }
-                existingAE->elements->data[j+firstIndex]
+                existingAE->elements->tdata()[j+firstIndex]
                     = new IntegerExp(newval->loc, val, elemType);
             }
             return newval;
@@ -3044,7 +3044,7 @@ Expression *BinExp::interpretAssignCommon(InterState *istate, CtfeGoal goal, fp_
             ArrayLiteralExp *newae = (ArrayLiteralExp *)newval;
             for (size_t j = 0; j < newae->elements->dim; j++)
             {
-                unsigned value = ((Expression *)(newae->elements->data[j]))->toInteger();
+                unsigned value = ((newae->elements->tdata()[j]))->toInteger();
                 switch (existingSE->sz)
                 {
                     case 1: s[j+firstIndex] = value; break;
@@ -3102,9 +3102,9 @@ Expression *BinExp::interpretAssignCommon(InterState *istate, CtfeGoal goal, fp_
             {
                 if (!directblk)
                     // Multidimensional array block assign
-                    recursiveBlockAssign((ArrayLiteralExp *)w->data[j+firstIndex], newval);
+                    recursiveBlockAssign((ArrayLiteralExp *)w->tdata()[j+firstIndex], newval);
                 else
-                    existingAE->elements->data[j+firstIndex] = newval;
+                    existingAE->elements->tdata()[j+firstIndex] = newval;
             }
             if (goal == ctfeNeedNothing)
                 return NULL; // avoid creating an unused literal
@@ -3377,11 +3377,11 @@ Expression *CallExp::interpret(InterState *istate, CtfeGoal goal)
             args.setDim(arguments->dim);
             for (size_t i = 0; i < args.dim; i++)
             {
-                Expression *earg = (Expression *)arguments->data[i];
+                Expression *earg = arguments->tdata()[i];
                 earg = earg->interpret(istate);
                 if (earg == EXP_CANT_INTERPRET)
                     return earg;
-                args.data[i] = (void *)earg;
+                args.tdata()[i] = earg;
             }
             e = eval_builtin(b, &args);
             if (!e)
@@ -3402,7 +3402,7 @@ Expression *CallExp::interpret(InterState *istate, CtfeGoal goal)
         // Inline .dup
         if (fd->ident == Id::adDup && arguments && arguments->dim == 2)
         {
-            e = (Expression *)arguments->data[1];
+            e = arguments->tdata()[1];
             e = e->interpret(istate);
             if (e != EXP_CANT_INTERPRET)
             {
@@ -3880,7 +3880,7 @@ Expression *DotVarExp::interpret(InterState *istate, CtfeGoal goal)
                         error("couldn't find field %s in %s", v->toChars(), type->toChars());
                         return EXP_CANT_INTERPRET;
                     }
-                    e = (Expression *)se->elements->data[i];
+                    e = se->elements->tdata()[i];
                     // If it is an lvalue literal, return it...
                     if (e->op == TOKstructliteral || e->op == TOKarrayliteral ||
                         e->op == TOKassocarrayliteral || e->op == TOKstring ||
@@ -3917,7 +3917,7 @@ Expression *interpret_aaLen(InterState *istate, Expressions *arguments)
 {
     if (!arguments || arguments->dim != 1)
         return NULL;
-    Expression *earg = (Expression *)arguments->data[0];
+    Expression *earg = arguments->tdata()[0];
     earg = earg->interpret(istate);
     if (earg == EXP_CANT_INTERPRET)
         return NULL;
@@ -3935,7 +3935,7 @@ Expression *interpret_aaKeys(InterState *istate, Expressions *arguments)
 #endif
     if (!arguments || arguments->dim != 2)
         return NULL;
-    Expression *earg = (Expression *)arguments->data[0];
+    Expression *earg = arguments->tdata()[0];
     earg = earg->interpret(istate);
     if (earg == EXP_CANT_INTERPRET)
         return NULL;
@@ -3957,7 +3957,7 @@ Expression *interpret_aaValues(InterState *istate, Expressions *arguments)
 #endif
     if (!arguments || arguments->dim != 3)
         return NULL;
-    Expression *earg = (Expression *)arguments->data[0];
+    Expression *earg = arguments->tdata()[0];
     earg = earg->interpret(istate);
     if (earg == EXP_CANT_INTERPRET)
         return NULL;
diff --git a/src/irstate.h b/src/irstate.h
index fa306ce73b30..fbe1eb1c8cf5 100644
--- a/src/irstate.h
+++ b/src/irstate.h
@@ -37,7 +37,7 @@ struct IRState
     Dsymbols *deferToObj;       // array of Dsymbol's to run toObjFile(int multiobj) on later
     elem *ehidden;              // transmit hidden pointer to CallExp::toElem()
     Symbol *startaddress;
-    Dsymbols *varsInScope;      // variables that are in scope that will need destruction later
+    VarDeclarations *varsInScope; // variables that are in scope that will need destruction later
 
     block *breakBlock;
     block *contBlock;
diff --git a/src/json.c b/src/json.c
index 8c33f4d26541..a1328bfb5113 100644
--- a/src/json.c
+++ b/src/json.c
@@ -51,7 +51,7 @@ void json_generate(Modules *modules)
 
     buf.writestring("[\n");
     for (int i = 0; i < modules->dim; i++)
-    {   Module *m = (Module *)modules->data[i];
+    {   Module *m = modules->tdata()[i];
         if (global.params.verbose)
             printf("json gen %s\n", m->toChars());
         m->toJsonBuffer(&buf);
@@ -64,7 +64,7 @@ void json_generate(Modules *modules)
     char *arg = global.params.xfilename;
     if (!arg || !*arg)
     {   // Generate lib file name from first obj name
-        char *n = (char *)global.params.objfiles->data[0];
+        char *n = global.params.objfiles->tdata()[0];
 
         n = FileName::name(n);
         FileName *fn = FileName::forceExt(n, global.json_ext);
@@ -193,7 +193,7 @@ void Module::toJsonBuffer(OutBuffer *buf)
 
     size_t offset = buf->offset;
     for (int i = 0; i < members->dim; i++)
-    {   Dsymbol *s = (Dsymbol *)members->data[i];
+    {   Dsymbol *s = members->tdata()[i];
         if (offset != buf->offset)
         {   buf->writestring(",\n");
             offset = buf->offset;
@@ -217,7 +217,7 @@ void AttribDeclaration::toJsonBuffer(OutBuffer *buf)
     {
         size_t offset = buf->offset;
         for (unsigned i = 0; i < d->dim; i++)
-        {   Dsymbol *s = (Dsymbol *)d->data[i];
+        {   Dsymbol *s = d->tdata()[i];
             //printf("AttribDeclaration::toJsonBuffer %s\n", s->toChars());
             if (offset != buf->offset)
             {   buf->writestring(",\n");
@@ -321,7 +321,7 @@ void AggregateDeclaration::toJsonBuffer(OutBuffer *buf)
         buf->writestring(" : [\n");
         size_t offset = buf->offset;
         for (int i = 0; i < members->dim; i++)
-        {   Dsymbol *s = (Dsymbol *)members->data[i];
+        {   Dsymbol *s = members->tdata()[i];
             if (offset != buf->offset)
             {   buf->writestring(",\n");
                 offset = buf->offset;
@@ -354,7 +354,7 @@ void TemplateDeclaration::toJsonBuffer(OutBuffer *buf)
     buf->writestring(" : [\n");
     size_t offset = buf->offset;
     for (int i = 0; i < members->dim; i++)
-    {   Dsymbol *s = (Dsymbol *)members->data[i];
+    {   Dsymbol *s = members->tdata()[i];
         if (offset != buf->offset)
         {   buf->writestring(",\n");
             offset = buf->offset;
@@ -376,7 +376,7 @@ void EnumDeclaration::toJsonBuffer(OutBuffer *buf)
         {
             for (int i = 0; i < members->dim; i++)
             {
-                Dsymbol *s = (Dsymbol *)members->data[i];
+                Dsymbol *s = members->tdata()[i];
                 s->toJsonBuffer(buf);
                 buf->writestring(",\n");
             }
@@ -404,7 +404,7 @@ void EnumDeclaration::toJsonBuffer(OutBuffer *buf)
         buf->writestring(" : [\n");
         size_t offset = buf->offset;
         for (int i = 0; i < members->dim; i++)
-        {   Dsymbol *s = (Dsymbol *)members->data[i];
+        {   Dsymbol *s = members->tdata()[i];
             if (offset != buf->offset)
             {   buf->writestring(",\n");
                 offset = buf->offset;
diff --git a/src/libelf.c b/src/libelf.c
index 2b7308b8f889..5e2e3f410554 100644
--- a/src/libelf.c
+++ b/src/libelf.c
@@ -46,7 +46,7 @@ void Library::setFilename(char *dir, char *filename)
     char *arg = filename;
     if (!arg || !*arg)
     {   // Generate lib file name from first obj name
-        char *n = (char *)global.params.objfiles->data[0];
+        char *n = global.params.objfiles->tdata()[0];
 
         n = FileName::name(n);
         FileName *fn = FileName::forceExt(n, global.lib_ext);
diff --git a/src/libmach.c b/src/libmach.c
index 7086f9ffeae8..d6776c0ea788 100644
--- a/src/libmach.c
+++ b/src/libmach.c
@@ -57,7 +57,7 @@ void Library::setFilename(char *dir, char *filename)
     char *arg = filename;
     if (!arg || !*arg)
     {   // Generate lib file name from first obj name
-        char *n = (char *)global.params.objfiles->data[0];
+        char *n = global.params.objfiles->tdata()[0];
 
         n = FileName::name(n);
         FileName *fn = FileName::forceExt(n, global.lib_ext);
@@ -479,7 +479,7 @@ void Library::addObject(const char *module_name, void *buf, size_t buflen)
                 {   reason = 12;
                     goto Lcorrupt;              // didn't find it
                 }
-                ObjModule *om = (ObjModule *)objmodules.data[m];
+                ObjModule *om = objmodules.tdata()[m];
                 //printf("\tom offset = x%x\n", (char *)om->base - (char *)buf);
                 if (moff == (char *)om->base - (char *)buf)
                 {
@@ -562,7 +562,7 @@ void Library::WriteLibToBuffer(OutBuffer *libbuf)
     /************* Scan Object Modules for Symbols ******************/
 
     for (int i = 0; i < objmodules.dim; i++)
-    {   ObjModule *om = (ObjModule *)objmodules.data[i];
+    {   ObjModule *om = objmodules.tdata()[i];
         if (om->scan)
         {
             scanObjModule(om);
@@ -574,7 +574,7 @@ void Library::WriteLibToBuffer(OutBuffer *libbuf)
     unsigned moffset = 8 + sizeof(Header) + 4 + 4;
 
     for (int i = 0; i < objsymbols.dim; i++)
-    {   ObjSymbol *os = (ObjSymbol *)objsymbols.data[i];
+    {   ObjSymbol *os = objsymbols.tdata()[i];
 
         moffset += 8 + strlen(os->name) + 1;
     }
@@ -588,7 +588,7 @@ void Library::WriteLibToBuffer(OutBuffer *libbuf)
 #endif
 
     for (int i = 0; i < objmodules.dim; i++)
-    {   ObjModule *om = (ObjModule *)objmodules.data[i];
+    {   ObjModule *om = objmodules.tdata()[i];
 
         moffset += moffset & 1;
         om->offset = moffset;
@@ -639,7 +639,7 @@ void Library::WriteLibToBuffer(OutBuffer *libbuf)
 
     int stringoff = 0;
     for (int i = 0; i < objsymbols.dim; i++)
-    {   ObjSymbol *os = (ObjSymbol *)objsymbols.data[i];
+    {   ObjSymbol *os = objsymbols.tdata()[i];
 
         sputl(stringoff, buf);
         libbuf->write(buf, 4);
@@ -654,7 +654,7 @@ void Library::WriteLibToBuffer(OutBuffer *libbuf)
     libbuf->write(buf, 4);
 
     for (int i = 0; i < objsymbols.dim; i++)
-    {   ObjSymbol *os = (ObjSymbol *)objsymbols.data[i];
+    {   ObjSymbol *os = objsymbols.tdata()[i];
 
         libbuf->writestring(os->name);
         libbuf->writeByte(0);
@@ -673,7 +673,7 @@ void Library::WriteLibToBuffer(OutBuffer *libbuf)
     /* Write out each of the object modules
      */
     for (int i = 0; i < objmodules.dim; i++)
-    {   ObjModule *om = (ObjModule *)objmodules.data[i];
+    {   ObjModule *om = objmodules.tdata()[i];
 
         if (libbuf->offset & 1)
             libbuf->writeByte('\n');    // module alignment
diff --git a/src/libomf.c b/src/libomf.c
index 7f136a484387..599a9266317e 100644
--- a/src/libomf.c
+++ b/src/libomf.c
@@ -42,7 +42,7 @@ void Library::setFilename(char *dir, char *filename)
     char *arg = filename;
     if (!arg || !*arg)
     {   // Generate lib file name from first obj name
-        char *n = (char *)global.params.objfiles->data[0];
+        char *n = global.params.objfiles->tdata()[0];
 
         n = FileName::name(n);
         FileName *fn = FileName::forceExt(n, global.lib_ext);
diff --git a/src/link.c b/src/link.c
index d7b62bc501fd..11e8d9050fd4 100644
--- a/src/link.c
+++ b/src/link.c
@@ -224,19 +224,19 @@ int runLINK()
     const char *cc = getenv("CC");
     if (!cc)
         cc = "gcc";
-    argv.push((void *)cc);
+    argv.push((char *)cc);
     argv.insert(1, global.params.objfiles);
 
 #if __APPLE__
     // If we are on Mac OS X and linking a dynamic library,
     // add the "-dynamiclib" flag
     if (global.params.dll)
-        argv.push((void *) "-dynamiclib");
+        argv.push((char *) "-dynamiclib");
 #endif
 
     // None of that a.out stuff. Use explicit exe file name, or
     // generate one from name of first source file.
-    argv.push((void *)"-o");
+    argv.push((char *)"-o");
     if (global.params.exefile)
     {
         if (global.params.dll)
@@ -245,7 +245,7 @@ int runLINK()
     }
     else
     {   // Generate exe file name from first obj name
-        char *n = (char *)global.params.objfiles->data[0];
+        char *n = global.params.objfiles->tdata()[0];
         char *e;
         char *ex;
 
@@ -274,20 +274,20 @@ int runLINK()
     }
 
     if (global.params.symdebug)
-        argv.push((void *)"-g");
+        argv.push((char *)"-g");
 
     if (global.params.isX86_64)
-        argv.push((void *)"-m64");
+        argv.push((char *)"-m64");
     else
-        argv.push((void *)"-m32");
+        argv.push((char *)"-m32");
 
     if (global.params.map || global.params.mapfile)
     {
-        argv.push((void *)"-Xlinker");
+        argv.push((char *)"-Xlinker");
 #if __APPLE__
-        argv.push((void *)"-map");
+        argv.push((char *)"-map");
 #else
-        argv.push((void *)"-Map");
+        argv.push((char *)"-Map");
 #endif
         if (!global.params.mapfile)
         {
@@ -302,7 +302,7 @@ int runLINK()
 
             global.params.mapfile = p;
         }
-        argv.push((void *)"-Xlinker");
+        argv.push((char *)"-Xlinker");
         argv.push(global.params.mapfile);
     }
 
@@ -318,16 +318,16 @@ int runLINK()
          * BUG: disabled because it causes exception handling to fail
          * because EH sections are "unreferenced" and elided
          */
-        argv.push((void *)"-Xlinker");
-        argv.push((void *)"--gc-sections");
+        argv.push((char *)"-Xlinker");
+        argv.push((char *)"--gc-sections");
     }
 
     for (i = 0; i < global.params.linkswitches->dim; i++)
-    {   char *p = (char *)global.params.linkswitches->data[i];
+    {   char *p = global.params.linkswitches->tdata()[i];
         if (!p || !p[0] || !(p[0] == '-' && p[1] == 'l'))
             // Don't need -Xlinker if switch starts with -l
-            argv.push((void *)"-Xlinker");
-        argv.push((void *) p);
+            argv.push((char *)"-Xlinker");
+        argv.push(p);
     }
 
     /* Add each library, prefixing it with "-l".
@@ -339,17 +339,17 @@ int runLINK()
      *  4. standard libraries.
      */
     for (i = 0; i < global.params.libfiles->dim; i++)
-    {   char *p = (char *)global.params.libfiles->data[i];
+    {   char *p = global.params.libfiles->tdata()[i];
         size_t plen = strlen(p);
         if (plen > 2 && p[plen - 2] == '.' && p[plen -1] == 'a')
-            argv.push((void *)p);
+            argv.push(p);
         else
         {
             char *s = (char *)mem.malloc(plen + 3);
             s[0] = '-';
             s[1] = 'l';
             memcpy(s + 2, p, plen + 1);
-            argv.push((void *)s);
+            argv.push(s);
         }
     }
 
@@ -362,17 +362,17 @@ int runLINK()
     char *buf = (char *)malloc(2 + strlen(libname) + 1);
     strcpy(buf, "-l");
     strcpy(buf + 2, libname);
-    argv.push((void *)buf);             // turns into /usr/lib/libphobos2.a
+    argv.push(buf);             // turns into /usr/lib/libphobos2.a
 
 //    argv.push((void *)"-ldruntime");
-    argv.push((void *)"-lpthread");
-    argv.push((void *)"-lm");
+    argv.push((char *)"-lpthread");
+    argv.push((char *)"-lm");
 
     if (!global.params.quiet || global.params.verbose)
     {
         // Print it
         for (i = 0; i < argv.dim; i++)
-            printf("%s ", (char *)argv.data[i]);
+            printf("%s ", argv.tdata()[i]);
         printf("\n");
         fflush(stdout);
     }
@@ -381,8 +381,8 @@ int runLINK()
     childpid = fork();
     if (childpid == 0)
     {
-        execvp((char *)argv.data[0], (char **)argv.data);
-        perror((char *)argv.data[0]);           // failed to execute
+        execvp(argv.tdata()[0], argv.tdata());
+        perror(argv.tdata()[0]);           // failed to execute
         return -1;
     }
 
@@ -543,7 +543,7 @@ int runProgram()
     // Build argv[]
     Strings argv;
 
-    argv.push((void *)global.params.exefile);
+    argv.push(global.params.exefile);
     for (size_t i = 0; i < global.params.runargs_length; i++)
     {   char *a = global.params.runargs[i];
 
@@ -555,7 +555,7 @@ int runProgram()
             a = b;
         }
 #endif
-        argv.push((void *)a);
+        argv.push(a);
     }
     argv.push(NULL);
 
@@ -573,12 +573,12 @@ int runProgram()
     childpid = fork();
     if (childpid == 0)
     {
-        const char *fn = (const char *)argv.data[0];
+        char *fn = argv.tdata()[0];
         if (!FileName::absolute(fn))
         {   // Make it "./fn"
             fn = FileName::combine(".", fn);
         }
-        execv(fn, (char **)argv.data);
+        execv(fn, argv.tdata());
         perror(fn);             // failed to execute
         return -1;
     }
diff --git a/src/mars.c b/src/mars.c
index f9ebd9c89fff..256edda0d032 100644
--- a/src/mars.c
+++ b/src/mars.c
@@ -909,7 +909,7 @@ int main(int argc, char *argv[])
     {
         for (i = 0; i < global.params.imppath->dim; i++)
         {
-            char *path = (char *)global.params.imppath->data[i];
+            char *path = global.params.imppath->tdata()[i];
             Strings *a = FileName::splitPath(path);
 
             if (a)
@@ -926,7 +926,7 @@ int main(int argc, char *argv[])
     {
         for (i = 0; i < global.params.fileImppath->dim; i++)
         {
-            char *path = (char *)global.params.fileImppath->data[i];
+            char *path = global.params.fileImppath->tdata()[i];
             Strings *a = FileName::splitPath(path);
 
             if (a)
@@ -947,7 +947,7 @@ int main(int argc, char *argv[])
         char *ext;
         char *name;
 
-        p = (char *) files.data[i];
+        p = files.tdata()[i];
 
 #if _WIN32
         // Convert / to \ so linker will work
@@ -965,47 +965,47 @@ int main(int argc, char *argv[])
              */
             if (FileName::equals(ext, global.obj_ext))
             {
-                global.params.objfiles->push(files.data[i]);
-                libmodules.push(files.data[i]);
+                global.params.objfiles->push(files.tdata()[i]);
+                libmodules.push(files.tdata()[i]);
                 continue;
             }
 
             if (FileName::equals(ext, global.lib_ext))
             {
-                global.params.libfiles->push(files.data[i]);
-                libmodules.push(files.data[i]);
+                global.params.libfiles->push(files.tdata()[i]);
+                libmodules.push(files.tdata()[i]);
                 continue;
             }
 
             if (strcmp(ext, global.ddoc_ext) == 0)
             {
-                global.params.ddocfiles->push(files.data[i]);
+                global.params.ddocfiles->push(files.tdata()[i]);
                 continue;
             }
 
             if (FileName::equals(ext, global.json_ext))
             {
                 global.params.doXGeneration = 1;
-                global.params.xfilename = (char *)files.data[i];
+                global.params.xfilename = files.tdata()[i];
                 continue;
             }
 
             if (FileName::equals(ext, global.map_ext))
             {
-                global.params.mapfile = (char *)files.data[i];
+                global.params.mapfile = files.tdata()[i];
                 continue;
             }
 
 #if TARGET_WINDOS
             if (FileName::equals(ext, "res"))
             {
-                global.params.resfile = (char *)files.data[i];
+                global.params.resfile = files.tdata()[i];
                 continue;
             }
 
             if (FileName::equals(ext, "def"))
             {
-                global.params.deffile = (char *)files.data[i];
+                global.params.deffile = files.tdata()[i];
                 continue;
             }
 
@@ -1036,7 +1036,7 @@ int main(int argc, char *argv[])
                     strcmp(name, ".") == 0)
                 {
                 Linvalid:
-                    error("invalid file name '%s'", (char *)files.data[i]);
+                    error("invalid file name '%s'", files.tdata()[i]);
                     fatal();
                 }
             }
@@ -1056,7 +1056,7 @@ int main(int argc, char *argv[])
          */
 
         Identifier *id = Lexer::idPool(name);
-        m = new Module((char *) files.data[i], id, global.params.doDocComments, global.params.doHdrGeneration);
+        m = new Module(files.tdata()[i], id, global.params.doDocComments, global.params.doHdrGeneration);
         modules.push(m);
 
         if (firstmodule)
@@ -1076,7 +1076,7 @@ int main(int argc, char *argv[])
     AsyncRead *aw = AsyncRead::create(modules.dim);
     for (i = 0; i < modules.dim; i++)
     {
-        m = (Module *)modules.data[i];
+        m = modules.tdata()[i];
         aw->addFile(m->srcfile);
     }
     aw->start();
@@ -1084,7 +1084,7 @@ int main(int argc, char *argv[])
     // Single threaded
     for (i = 0; i < modules.dim; i++)
     {
-        m = (Module *)modules.data[i];
+        m = modules.tdata()[i];
         m->read(0);
     }
 #endif
@@ -1093,7 +1093,7 @@ int main(int argc, char *argv[])
     int anydocfiles = 0;
     for (i = 0; i < modules.dim; i++)
     {
-        m = (Module *)modules.data[i];
+        m = modules.tdata()[i];
         if (global.params.verbose)
             printf("parse     %s\n", m->toChars());
         if (!Module::rootModule)
@@ -1120,7 +1120,7 @@ int main(int argc, char *argv[])
             // Remove m's object file from list of object files
             for (int j = 0; j < global.params.objfiles->dim; j++)
             {
-                if (m->objfile->name->str == global.params.objfiles->data[j])
+                if (m->objfile->name->str == global.params.objfiles->tdata()[j])
                 {
                     global.params.objfiles->remove(j);
                     break;
@@ -1153,7 +1153,7 @@ int main(int argc, char *argv[])
          */
         for (i = 0; i < modules.dim; i++)
         {
-            m = (Module *)modules.data[i];
+            m = modules.tdata()[i];
             if (global.params.verbose)
                 printf("import    %s\n", m->toChars());
             m->genhdrfile();
@@ -1166,7 +1166,7 @@ int main(int argc, char *argv[])
     // load all unconditional imports for better symbol resolving
     for (i = 0; i < modules.dim; i++)
     {
-       m = (Module *)modules.data[i];
+       m = modules.tdata()[i];
        if (global.params.verbose)
            printf("importall %s\n", m->toChars());
        m->importAll(0);
@@ -1177,7 +1177,7 @@ int main(int argc, char *argv[])
     // Do semantic analysis
     for (i = 0; i < modules.dim; i++)
     {
-        m = (Module *)modules.data[i];
+        m = modules.tdata()[i];
         if (global.params.verbose)
             printf("semantic  %s\n", m->toChars());
         m->semantic();
@@ -1191,7 +1191,7 @@ int main(int argc, char *argv[])
     // Do pass 2 semantic analysis
     for (i = 0; i < modules.dim; i++)
     {
-        m = (Module *)modules.data[i];
+        m = modules.tdata()[i];
         if (global.params.verbose)
             printf("semantic2 %s\n", m->toChars());
         m->semantic2();
@@ -1202,7 +1202,7 @@ int main(int argc, char *argv[])
     // Do pass 3 semantic analysis
     for (i = 0; i < modules.dim; i++)
     {
-        m = (Module *)modules.data[i];
+        m = modules.tdata()[i];
         if (global.params.verbose)
             printf("semantic3 %s\n", m->toChars());
         m->semantic3();
@@ -1235,7 +1235,7 @@ int main(int argc, char *argv[])
             // since otherwise functions in them cannot be inlined
             for (i = 0; i < Module::amodules.dim; i++)
             {
-                m = (Module *)Module::amodules.data[i];
+                m = Module::amodules.tdata()[i];
                 if (global.params.verbose)
                     printf("semantic3 %s\n", m->toChars());
                 m->semantic3();
@@ -1246,7 +1246,7 @@ int main(int argc, char *argv[])
 
         for (i = 0; i < modules.dim; i++)
         {
-            m = (Module *)modules.data[i];
+            m = modules.tdata()[i];
             if (global.params.verbose)
                 printf("inline scan %s\n", m->toChars());
             m->inlineScan();
@@ -1266,7 +1266,7 @@ int main(int argc, char *argv[])
         // Add input object and input library files to output library
         for (int i = 0; i < libmodules.dim; i++)
         {
-            char *p = (char *)libmodules.data[i];
+            char *p = libmodules.tdata()[i];
             library->addObject(p, NULL, 0);
         }
     }
@@ -1280,7 +1280,7 @@ int main(int argc, char *argv[])
     {
         for (i = 0; i < modules.dim; i++)
         {
-            m = (Module *)modules.data[i];
+            m = modules.tdata()[i];
             if (global.params.verbose)
                 printf("code      %s\n", m->toChars());
             if (i == 0)
@@ -1291,14 +1291,14 @@ int main(int argc, char *argv[])
         }
         if (!global.errors && modules.dim)
         {
-            obj_end(library, ((Module *)modules.data[0])->objfile);
+            obj_end(library, modules.tdata()[0]->objfile);
         }
     }
     else
     {
         for (i = 0; i < modules.dim; i++)
         {
-            m = (Module *)modules.data[i];
+            m = modules.tdata()[i];
             if (global.params.verbose)
                 printf("code      %s\n", m->toChars());
             if (global.params.obj)
@@ -1355,7 +1355,7 @@ int main(int argc, char *argv[])
                  */
                 for (i = 0; i < modules.dim; i++)
                 {
-                    Module *m = (Module *)modules.data[i];
+                    Module *m = modules.tdata()[i];
                     m->deleteObjFile();
                     if (global.params.oneobj)
                         break;
@@ -1395,7 +1395,7 @@ void getenv_setargv(const char *envvar, int *pargc, char** *pargv)
     argv->setDim(argc);
 
     for (int i = 0; i < argc; i++)
-        argv->data[i] = (void *)(*pargv)[i];
+        argv->tdata()[i] = (*pargv)[i];
 
     int j = 1;                  // leave argv[0] alone
     while (1)
@@ -1471,7 +1471,7 @@ void getenv_setargv(const char *envvar, int *pargc, char** *pargv)
 
 Ldone:
     *pargc = argc;
-    *pargv = (char **)argv->data;
+    *pargv = argv->tdata();
 }
 
 #if WINDOWS_SEH
diff --git a/src/mars.h b/src/mars.h
index 1c7cc2658f63..a68987daba7b 100644
--- a/src/mars.h
+++ b/src/mars.h
@@ -189,10 +189,10 @@ struct Param
     char *xfilename;            // write JSON file to xfilename
 
     unsigned debuglevel;        // debug level
-    Identifiers *debugids;      // debug identifiers
+    Strings *debugids;     // debug identifiers
 
     unsigned versionlevel;      // version level
-    Identifiers *versionids;    // version identifiers
+    Strings *versionids;   // version identifiers
 
     bool dump_source;
 
diff --git a/src/module.c b/src/module.c
index 7aaae8189b15..c392372d710a 100644
--- a/src/module.c
+++ b/src/module.c
@@ -277,7 +277,7 @@ Module *Module::load(Loc loc, Identifiers *packages, Identifier *ident)
         int i;
 
         for (i = 0; i < packages->dim; i++)
-        {   Identifier *pid = (Identifier *)packages->data[i];
+        {   Identifier *pid = packages->tdata()[i];
 
             buf.writestring(pid->toChars());
 #if _WIN32
@@ -314,7 +314,7 @@ Module *Module::load(Loc loc, Identifiers *packages, Identifier *ident)
     {
         for (size_t i = 0; i < global.path->dim; i++)
         {
-            char *p = (char *)global.path->data[i];
+            char *p = global.path->tdata()[i];
             char *n = FileName::combine(p, sdi);
             if (FileName::exists(n))
             {   result = n;
@@ -338,7 +338,7 @@ Module *Module::load(Loc loc, Identifiers *packages, Identifier *ident)
         if (packages)
         {
             for (size_t i = 0; i < packages->dim; i++)
-            {   Identifier *pid = (Identifier *)packages->data[i];
+            {   Identifier *pid = packages->tdata()[i];
                 printf("%s.", pid->toChars());
             }
         }
@@ -367,7 +367,7 @@ void Module::read(Loc loc)
             {
                 for (int i = 0; i < global.path->dim; i++)
                 {
-                    char *p = (char *)global.path->data[i];
+                    char *p = global.path->tdata()[i];
                     fprintf(stdmsg, "import path[%d] = %s\n", i, p);
                 }
             }
@@ -686,7 +686,7 @@ void Module::importAll(Scope *prevsc)
     // Add import of "object" if this module isn't "object"
     if (ident != Id::object)
     {
-        if (members->dim == 0 || ((Dsymbol *)members->data[0])->ident != Id::object)
+        if (members->dim == 0 || members->tdata()[0]->ident != Id::object)
         {
             Import *im = new Import(0, NULL, Id::object, NULL, 0);
             members->shift(im);
@@ -699,7 +699,7 @@ void Module::importAll(Scope *prevsc)
         symtab = new DsymbolTable();
         for (int i = 0; i < members->dim; i++)
         {
-            Dsymbol *s = (Dsymbol *)members->data[i];
+            Dsymbol *s = members->tdata()[i];
             s->addMember(NULL, sc->scopesym, 1);
         }
     }
@@ -712,13 +712,13 @@ void Module::importAll(Scope *prevsc)
      */
     setScope(sc);               // remember module scope for semantic
     for (int i = 0; i < members->dim; i++)
-    {   Dsymbol *s = (Dsymbol *)members->data[i];
+    {   Dsymbol *s = members->tdata()[i];
         s->setScope(sc);
     }
 
     for (int i = 0; i < members->dim; i++)
     {
-        Dsymbol *s = (Dsymbol *)members->data[i];
+        Dsymbol *s = members->tdata()[i];
         s->importAll(sc);
     }
 
@@ -773,7 +773,7 @@ void Module::semantic()
 
     // Do semantic() on members that don't depend on others
     for (int i = 0; i < members->dim; i++)
-    {   Dsymbol *s = (Dsymbol *)members->data[i];
+    {   Dsymbol *s = members->tdata()[i];
 
         //printf("\tModule('%s'): '%s'.semantic0()\n", toChars(), s->toChars());
         s->semantic0(sc);
@@ -781,7 +781,7 @@ void Module::semantic()
 
     // Pass 1 semantic routines: do public side of the definition
     for (int i = 0; i < members->dim; i++)
-    {   Dsymbol *s = (Dsymbol *)members->data[i];
+    {   Dsymbol *s = members->tdata()[i];
 
         //printf("\tModule('%s'): '%s'.semantic()\n", toChars(), s->toChars());
         s->semantic(sc);
@@ -803,7 +803,7 @@ void Module::semantic2()
     {
         for (int i = 0; i < deferred.dim; i++)
         {
-            Dsymbol *sd = (Dsymbol *)deferred.data[i];
+            Dsymbol *sd = deferred.tdata()[i];
 
             sd->error("unable to resolve forward reference in definition");
         }
@@ -825,7 +825,7 @@ void Module::semantic2()
     for (i = 0; i < members->dim; i++)
     {   Dsymbol *s;
 
-        s = (Dsymbol *)members->data[i];
+        s = members->tdata()[i];
         s->semantic2(sc);
     }
 
@@ -854,7 +854,7 @@ void Module::semantic3()
     for (i = 0; i < members->dim; i++)
     {   Dsymbol *s;
 
-        s = (Dsymbol *)members->data[i];
+        s = members->tdata()[i];
         //printf("Module %s: %s.semantic3()\n", toChars(), s->toChars());
         s->semantic3(sc);
     }
@@ -877,7 +877,7 @@ void Module::inlineScan()
     //printf("Module = %p\n", sc.scopesym);
 
     for (int i = 0; i < members->dim; i++)
-    {   Dsymbol *s = (Dsymbol *)members->data[i];
+    {   Dsymbol *s = members->tdata()[i];
         //if (global.params.verbose)
             //printf("inline scan symbol %s\n", s->toChars());
 
@@ -900,7 +900,7 @@ void Module::gensymfile()
     buf.writenl();
 
     for (int i = 0; i < members->dim; i++)
-    {   Dsymbol *s = (Dsymbol *)members->data[i];
+    {   Dsymbol *s = members->tdata()[i];
 
         s->toCBuffer(&buf, &hgs);
     }
@@ -961,7 +961,7 @@ Dsymbol *Module::symtabInsert(Dsymbol *s)
 void Module::clearCache()
 {
     for (int i = 0; i < amodules.dim; i++)
-    {   Module *m = (Module *)amodules.data[i];
+    {   Module *m = amodules.tdata()[i];
         m->searchCacheIdent = NULL;
     }
 }
@@ -975,7 +975,7 @@ void Module::addDeferredSemantic(Dsymbol *s)
     // Don't add it if it is already there
     for (int i = 0; i < deferred.dim; i++)
     {
-        Dsymbol *sd = (Dsymbol *)deferred.data[i];
+        Dsymbol *sd = deferred.tdata()[i];
 
         if (sd == s)
             return;
@@ -1020,7 +1020,7 @@ void Module::runDeferredSemantic()
             todo = (Dsymbol **)alloca(len * sizeof(Dsymbol *));
             assert(todo);
         }
-        memcpy(todo, deferred.data, len * sizeof(Dsymbol *));
+        memcpy(todo, deferred.tdata(), len * sizeof(Dsymbol *));
         deferred.setDim(0);
 
         for (int i = 0; i < len; i++)
@@ -1053,7 +1053,7 @@ int Module::imports(Module *m)
     }
 #endif
     for (int i = 0; i < aimports.dim; i++)
-    {   Module *mi = (Module *)aimports.data[i];
+    {   Module *mi = aimports.tdata()[i];
         if (mi == m)
             return TRUE;
         if (!mi->insearch)
@@ -1077,7 +1077,7 @@ int Module::selfImports()
     if (!selfimports)
     {
         for (int i = 0; i < amodules.dim; i++)
-        {   Module *mi = (Module *)amodules.data[i];
+        {   Module *mi = amodules.tdata()[i];
             //printf("\t[%d] %s\n", i, mi->toChars());
             mi->insearch = 0;
         }
@@ -1085,7 +1085,7 @@ int Module::selfImports()
         selfimports = imports(this) + 1;
 
         for (int i = 0; i < amodules.dim; i++)
-        {   Module *mi = (Module *)amodules.data[i];
+        {   Module *mi = amodules.tdata()[i];
             //printf("\t[%d] %s\n", i, mi->toChars());
             mi->insearch = 0;
         }
@@ -1111,7 +1111,7 @@ char *ModuleDeclaration::toChars()
     if (packages && packages->dim)
     {
         for (i = 0; i < packages->dim; i++)
-        {   Identifier *pid = (Identifier *)packages->data[i];
+        {   Identifier *pid = packages->tdata()[i];
 
             buf.writestring(pid->toChars());
             buf.writeByte('.');
@@ -1149,7 +1149,7 @@ DsymbolTable *Package::resolve(Identifiers *packages, Dsymbol **pparent, Package
     {   int i;
 
         for (i = 0; i < packages->dim; i++)
-        {   Identifier *pid = (Identifier *)packages->data[i];
+        {   Identifier *pid = packages->tdata()[i];
             Dsymbol *p;
 
             p = dst->lookup(pid);
diff --git a/src/module.h b/src/module.h
index 0187f838cef0..b1c278db8f2f 100644
--- a/src/module.h
+++ b/src/module.h
@@ -97,12 +97,12 @@ struct Module : Package
     ModuleInfoDeclaration *vmoduleinfo;
 
     unsigned debuglevel;        // debug level
-    Identifiers *debugids;      // debug identifiers
-    Identifiers *debugidsNot;   // forward referenced debug identifiers
+    Strings *debugids;      // debug identifiers
+    Strings *debugidsNot;       // forward referenced debug identifiers
 
     unsigned versionlevel;      // version level
-    Identifiers *versionids;    // version identifiers
-    Identifiers *versionidsNot; // forward referenced version identifiers
+    Strings *versionids;    // version identifiers
+    Strings *versionidsNot;     // forward referenced version identifiers
 
     Macro *macrotable;          // document comment macros
     Escape *escapetable;        // document comment escapes
diff --git a/src/mtype.c b/src/mtype.c
index d1472ab01cbe..fce704ad0940 100644
--- a/src/mtype.c
+++ b/src/mtype.c
@@ -3279,7 +3279,7 @@ void TypeSArray::resolve(Loc loc, Scope *sc, Expression **pe, Type **pt, Dsymbol
             {   error(loc, "tuple index %ju exceeds length %u", d, td->objects->dim);
                 goto Ldefault;
             }
-            Object *o = (Object *)td->objects->data[(size_t)d];
+            Object *o = td->objects->tdata()[(size_t)d];
             if (o->dyncast() == DYNCAST_DSYMBOL)
             {
                 *ps = (Dsymbol *)o;
@@ -3299,7 +3299,7 @@ void TypeSArray::resolve(Loc loc, Scope *sc, Expression **pe, Type **pt, Dsymbol
              */
             Objects *objects = new Objects;
             objects->setDim(1);
-            objects->data[0] = o;
+            objects->tdata()[0] = o;
 
             TupleDeclaration *tds = new TupleDeclaration(loc, td->ident, objects);
             *ps = tds;
@@ -3333,7 +3333,7 @@ Type *TypeSArray::semantic(Loc loc, Scope *sc)
         {   error(loc, "tuple index %ju exceeds %u", d, sd->objects->dim);
             return Type::terror;
         }
-        Object *o = (Object *)sd->objects->data[(size_t)d];
+        Object *o = sd->objects->tdata()[(size_t)d];
         if (o->dyncast() != DYNCAST_TYPE)
         {   error(loc, "%s is not a type", toChars());
             return Type::terror;
@@ -3407,7 +3407,7 @@ Type *TypeSArray::semantic(Loc loc, Scope *sc)
             {   error(loc, "tuple index %ju exceeds %u", d, tt->arguments->dim);
                 goto Lerror;
             }
-            Parameter *arg = (Parameter *)tt->arguments->data[(size_t)d];
+            Parameter *arg = tt->arguments->tdata()[(size_t)d];
             return arg->type;
         }
         case Tstruct:
@@ -3593,7 +3593,7 @@ Expression *TypeSArray::defaultInitLiteral(Loc loc)
     Expressions *elements = new Expressions();
     elements->setDim(d);
     for (size_t i = 0; i < d; i++)
-        elements->data[i] = elementinit;
+        elements->tdata()[i] = elementinit;
     ArrayLiteralExp *ae = new ArrayLiteralExp(0, elements);
     ae->type = this;
     return ae;
@@ -4863,10 +4863,10 @@ Type *TypeFunction::semantic(Loc loc, Scope *sc)
     if (parameters)
     {   tf->parameters = (Parameters *)parameters->copy();
         for (size_t i = 0; i < parameters->dim; i++)
-        {   Parameter *arg = (Parameter *)parameters->data[i];
+        {   Parameter *arg = parameters->tdata()[i];
             Parameter *cpy = (Parameter *)mem.malloc(sizeof(Parameter));
             memcpy(cpy, arg, sizeof(Parameter));
-            tf->parameters->data[i] = (void *)cpy;
+            tf->parameters->tdata()[i] = cpy;
         }
     }
 
@@ -4990,7 +4990,7 @@ Type *TypeFunction::semantic(Loc loc, Scope *sc)
                 {
                     size_t tdim = tt->arguments->dim;
                     for (size_t j = 0; j < tdim; j++)
-                    {   Parameter *narg = (Parameter *)tt->arguments->data[j];
+                    {   Parameter *narg = tt->arguments->tdata()[j];
                         narg->storageClass = fparam->storageClass;
                     }
                 }
@@ -5009,7 +5009,7 @@ Type *TypeFunction::semantic(Loc loc, Scope *sc)
             if (fparam->storageClass & STCauto)
             {
                 if (fargs && i < fargs->dim)
-                {   Expression *farg = (Expression *)fargs->data[i];
+                {   Expression *farg = fargs->tdata()[i];
                     if (farg->isLvalue())
                         ;                               // ref parameter
                     else
@@ -5182,7 +5182,7 @@ int TypeFunction::callMatch(Expression *ethis, Expressions *args, int flag)
                 goto L1;
             goto Nomatch;               // not enough arguments
         }
-        arg = (Expression *)args->data[u];
+        arg = args->tdata()[u];
         assert(arg);
         //printf("arg: %s, type: %s\n", arg->toChars(), arg->type->toChars());
 
@@ -5259,7 +5259,7 @@ int TypeFunction::callMatch(Expression *ethis, Expressions *args, int flag)
                     {   TypeArray *ta = (TypeArray *)tb;
                         for (; u < nargs; u++)
                         {
-                            arg = (Expression *)args->data[u];
+                            arg = args->tdata()[u];
                             assert(arg);
 #if 1
                             /* If lazy array of delegates,
@@ -5514,7 +5514,7 @@ void TypeQualified::syntaxCopyHelper(TypeQualified *t)
     idents.setDim(t->idents.dim);
     for (int i = 0; i < idents.dim; i++)
     {
-        Identifier *id = (Identifier *)t->idents.data[i];
+        Identifier *id = t->idents.tdata()[i];
         if (id->dyncast() == DYNCAST_DSYMBOL)
         {
             TemplateInstance *ti = (TemplateInstance *)id;
@@ -5522,7 +5522,7 @@ void TypeQualified::syntaxCopyHelper(TypeQualified *t)
             ti = (TemplateInstance *)ti->syntaxCopy(NULL);
             id = (Identifier *)ti;
         }
-        idents.data[i] = id;
+        idents.tdata()[i] = id;
     }
 }
 
@@ -5537,7 +5537,7 @@ void TypeQualified::toCBuffer2Helper(OutBuffer *buf, HdrGenState *hgs)
     int i;
 
     for (i = 0; i < idents.dim; i++)
-    {   Identifier *id = (Identifier *)idents.data[i];
+    {   Identifier *id = idents.tdata()[i];
 
         buf->writeByte('.');
 
@@ -5591,7 +5591,7 @@ void TypeQualified::resolveHelper(Loc loc, Scope *sc,
         //printf("\t2: s = '%s' %p, kind = '%s'\n",s->toChars(), s, s->kind());
         for (int i = 0; i < idents.dim; i++)
         {
-            Identifier *id = (Identifier *)idents.data[i];
+            Identifier *id = idents.tdata()[i];
             Dsymbol *sm = s->searchX(loc, sc, id);
             //printf("\t3: s = '%s' %p, kind = '%s'\n",s->toChars(), s, s->kind());
             //printf("\tgetType = '%s'\n", s->getType()->toChars());
@@ -5614,7 +5614,7 @@ void TypeQualified::resolveHelper(Loc loc, Scope *sc,
                     e = new DsymbolExp(loc, s, 0);
                     do
                     {
-                        id = (Identifier *)idents.data[i];
+                        id = idents.tdata()[i];
                         e = new DotIdExp(loc, e, id);
                     } while (++i < idents.dim);
                     e = e->semantic(sc);
@@ -5640,7 +5640,7 @@ void TypeQualified::resolveHelper(Loc loc, Scope *sc,
                 L3:
                     for (; i < idents.dim; i++)
                     {
-                        id = (Identifier *)idents.data[i];
+                        id = idents.tdata()[i];
                         //printf("e: '%s', id: '%s', type = %p\n", e->toChars(), id->toChars(), e->type);
                         if (id == Id::offsetof || !e->type)
                         {   e = new DotIdExp(e->loc, e, id);
@@ -5835,7 +5835,7 @@ Dsymbol *TypeIdentifier::toDsymbol(Scope *sc)
     {
         for (int i = 0; i < idents.dim; i++)
         {
-            Identifier *id = (Identifier *)idents.data[i];
+            Identifier *id = idents.tdata()[i];
             s = s->searchX(loc, sc, id);
             if (!s)                 // failed to find a symbol
             {   //printf("\tdidn't find a symbol\n");
@@ -5895,7 +5895,7 @@ Expression *TypeIdentifier::toExpression()
     Expression *e = new IdentifierExp(loc, ident);
     for (int i = 0; i < idents.dim; i++)
     {
-        Identifier *id = (Identifier *)idents.data[i];
+        Identifier *id = idents.tdata()[i];
         e = new DotIdExp(loc, e, id);
     }
 
@@ -6166,7 +6166,7 @@ Type *TypeTypeof::semantic(Loc loc, Scope *sc)
         {
             if (!s)
                 break;
-            Identifier *id = (Identifier *)idents.data[i];
+            Identifier *id = idents.tdata()[i];
             s = s->searchX(loc, sc, id);
         }
 
@@ -6246,7 +6246,7 @@ Type *TypeReturn::semantic(Loc loc, Scope *sc)
         {
             if (!s)
                 break;
-            Identifier *id = (Identifier *)idents.data[i];
+            Identifier *id = idents.tdata()[i];
             s = s->searchX(loc, sc, id);
         }
         if (s)
@@ -6915,7 +6915,7 @@ Expression *TypeStruct::dotExp(Scope *sc, Expression *e, Identifier *ident)
         Expressions *exps = new Expressions;
         exps->reserve(sym->fields.dim);
         for (size_t i = 0; i < sym->fields.dim; i++)
-        {   VarDeclaration *v = (VarDeclaration *)sym->fields.data[i];
+        {   VarDeclaration *v = sym->fields.tdata()[i];
             Expression *fe = new DotVarExp(e->loc, e, v);
             exps->push(fe);
         }
@@ -7127,7 +7127,7 @@ Expression *TypeStruct::defaultInitLiteral(Loc loc)
     structelems->setDim(sym->fields.dim);
     for (size_t j = 0; j < structelems->dim; j++)
     {
-        VarDeclaration *vd = (VarDeclaration *)(sym->fields.data[j]);
+        VarDeclaration *vd = sym->fields.tdata()[j];
         Expression *e;
         if (vd->init)
         {   if (vd->init->isVoidInitializer())
@@ -7137,7 +7137,7 @@ Expression *TypeStruct::defaultInitLiteral(Loc loc)
         }
         else
             e = vd->type->defaultInitLiteral();
-        structelems->data[j] = e;
+        structelems->tdata()[j] = e;
     }
     StructLiteralExp *structinit = new StructLiteralExp(loc, (StructDeclaration *)sym, structelems);
     // Why doesn't the StructLiteralExp constructor do this, when
@@ -7168,7 +7168,7 @@ int TypeStruct::isAssignable()
      * then one cannot assign this struct.
      */
     for (size_t i = 0; i < sym->fields.dim; i++)
-    {   VarDeclaration *v = (VarDeclaration *)sym->fields.data[i];
+    {   VarDeclaration *v = sym->fields.tdata()[i];
         if (v->isConst() || v->isImmutable())
             return FALSE;
     }
@@ -7183,7 +7183,7 @@ int TypeStruct::hasPointers()
     sym->size(0);               // give error for forward references
     for (size_t i = 0; i < s->fields.dim; i++)
     {
-        Dsymbol *sm = (Dsymbol *)s->fields.data[i];
+        Dsymbol *sm = s->fields.tdata()[i];
         Declaration *d = sm->isDeclaration();
         if (d->storage_class & STCref || d->hasPointers())
             return TRUE;
@@ -7249,7 +7249,7 @@ MATCH TypeStruct::implicitConvTo(Type *to)
                  * allow the conversion.
                  */
                 for (int i = 0; i < sym->fields.dim; i++)
-                {   Dsymbol *s = (Dsymbol *)sym->fields.data[i];
+                {   Dsymbol *s = sym->fields.tdata()[i];
                     VarDeclaration *v = s->isVarDeclaration();
                     assert(v && v->storage_class & STCfield);
 
@@ -7378,7 +7378,7 @@ Expression *TypeClass::dotExp(Scope *sc, Expression *e, Identifier *ident)
         Expressions *exps = new Expressions;
         exps->reserve(sym->fields.dim);
         for (size_t i = 0; i < sym->fields.dim; i++)
-        {   VarDeclaration *v = (VarDeclaration *)sym->fields.data[i];
+        {   VarDeclaration *v = sym->fields.tdata()[i];
             // Don't include hidden 'this' pointer
             if (v->isThisDeclaration())
                 continue;
@@ -7740,7 +7740,7 @@ TypeTuple::TypeTuple(Parameters *arguments)
     {
         for (size_t i = 0; i < arguments->dim; i++)
         {
-            Parameter *arg = (Parameter *)arguments->data[i];
+            Parameter *arg = arguments->tdata()[i];
             assert(arg && arg->type);
         }
     }
@@ -7760,11 +7760,11 @@ TypeTuple::TypeTuple(Expressions *exps)
     {
         arguments->setDim(exps->dim);
         for (size_t i = 0; i < exps->dim; i++)
-        {   Expression *e = (Expression *)exps->data[i];
+        {   Expression *e = exps->tdata()[i];
             if (e->type->ty == Ttuple)
                 e->error("cannot form tuple of tuples");
             Parameter *arg = new Parameter(STCundefined, e->type, NULL, NULL);
-            arguments->data[i] = (void *)arg;
+            arguments->tdata()[i] = arg;
         }
     }
     this->arguments = arguments;
@@ -7831,8 +7831,8 @@ int TypeTuple::equals(Object *o)
         if (arguments->dim == tt->arguments->dim)
         {
             for (size_t i = 0; i < tt->arguments->dim; i++)
-            {   Parameter *arg1 = (Parameter *)arguments->data[i];
-                Parameter *arg2 = (Parameter *)tt->arguments->data[i];
+            {   Parameter *arg1 = arguments->tdata()[i];
+                Parameter *arg2 = tt->arguments->tdata()[i];
 
                 if (!arg1->type->equals(arg2->type))
                     return 0;
@@ -7849,7 +7849,7 @@ Type *TypeTuple::reliesOnTident()
     {
         for (size_t i = 0; i < arguments->dim; i++)
         {
-            Parameter *arg = (Parameter *)arguments->data[i];
+            Parameter *arg = arguments->tdata()[i];
             Type *t = arg->type->reliesOnTident();
             if (t)
                 return t;
@@ -7868,9 +7868,9 @@ Type *TypeTuple::makeConst()
     t->arguments = new Parameters();
     t->arguments->setDim(arguments->dim);
     for (size_t i = 0; i < arguments->dim; i++)
-    {   Parameter *arg = (Parameter *)arguments->data[i];
+    {   Parameter *arg = arguments->tdata()[i];
         Parameter *narg = new Parameter(arg->storageClass, arg->type->constOf(), arg->ident, arg->defaultArg);
-        t->arguments->data[i] = (Parameter *)narg;
+        t->arguments->tdata()[i] = (Parameter *)narg;
     }
     return t;
 }
@@ -7958,7 +7958,7 @@ Type *TypeSlice::semantic(Loc loc, Scope *sc)
     Parameters *args = new Parameters;
     args->reserve(i2 - i1);
     for (size_t i = i1; i < i2; i++)
-    {   Parameter *arg = (Parameter *)tt->arguments->data[i];
+    {   Parameter *arg = tt->arguments->tdata()[i];
         args->push(arg);
     }
 
@@ -8014,7 +8014,7 @@ void TypeSlice::resolve(Loc loc, Scope *sc, Expression **pe, Type **pt, Dsymbol
             objects->setDim(i2 - i1);
             for (size_t i = 0; i < objects->dim; i++)
             {
-                objects->data[i] = td->objects->data[(size_t)i1 + i];
+                objects->tdata()[i] = td->objects->tdata()[(size_t)i1 + i];
             }
 
             TupleDeclaration *tds = new TupleDeclaration(loc, td->ident, objects);
@@ -8090,10 +8090,10 @@ Parameters *Parameter::arraySyntaxCopy(Parameters *args)
         a = new Parameters();
         a->setDim(args->dim);
         for (size_t i = 0; i < a->dim; i++)
-        {   Parameter *arg = (Parameter *)args->data[i];
+        {   Parameter *arg = args->tdata()[i];
 
             arg = arg->syntaxCopy();
-            a->data[i] = (void *)arg;
+            a->tdata()[i] = arg;
         }
     }
     return a;
@@ -8115,7 +8115,7 @@ char *Parameter::argsTypesToChars(Parameters *args, int varargs)
         for (int i = 0; i < args->dim; i++)
         {   if (i)
                 buf->writeByte(',');
-            Parameter *arg = (Parameter *)args->data[i];
+            Parameter *arg = args->tdata()[i];
             argbuf.reset();
             arg->type->toCBuffer2(&argbuf, &hgs, 0);
             buf->write(&argbuf);
@@ -8143,7 +8143,7 @@ void Parameter::argsToCBuffer(OutBuffer *buf, HdrGenState *hgs, Parameters *argu
         {
             if (i)
                 buf->writestring(", ");
-            Parameter *arg = (Parameter *)arguments->data[i];
+            Parameter *arg = arguments->tdata()[i];
 
             if (arg->storageClass & STCauto)
                 buf->writestring("auto ");
@@ -8309,7 +8309,7 @@ size_t Parameter::dim(Parameters *args)
     if (args)
     {
         for (size_t i = 0; i < args->dim; i++)
-        {   Parameter *arg = (Parameter *)args->data[i];
+        {   Parameter *arg = args->tdata()[i];
             Type *t = arg->type->toBasetype();
 
             if (t->ty == Ttuple)
@@ -8338,7 +8338,7 @@ Parameter *Parameter::getNth(Parameters *args, size_t nth, size_t *pn)
 
     size_t n = 0;
     for (size_t i = 0; i < args->dim; i++)
-    {   Parameter *arg = (Parameter *)args->data[i];
+    {   Parameter *arg = args->tdata()[i];
         Type *t = arg->type->toBasetype();
 
         if (t->ty == Ttuple)
diff --git a/src/opover.c b/src/opover.c
index 1bc86aa073d9..0bc43e65efb7 100644
--- a/src/opover.c
+++ b/src/opover.c
@@ -501,9 +501,9 @@ Expression *BinExp::op_overload(Scope *sc)
          */
 
         args1.setDim(1);
-        args1.data[0] = (void*) e1;
+        args1.tdata()[0] = e1;
         args2.setDim(1);
-        args2.data[0] = (void*) e2;
+        args2.tdata()[0] = e2;
         argsset = 1;
 
         Match m;
@@ -594,9 +594,9 @@ Expression *BinExp::op_overload(Scope *sc)
 
             if (!argsset)
             {   args1.setDim(1);
-                args1.data[0] = (void*) e1;
+                args1.tdata()[0] = e1;
                 args2.setDim(1);
-                args2.data[0] = (void*) e2;
+                args2.tdata()[0] = e2;
             }
 
             Match m;
@@ -753,9 +753,9 @@ Expression *BinExp::compare_overload(Scope *sc, Identifier *id)
         Expressions args2;
 
         args1.setDim(1);
-        args1.data[0] = (void*) e1;
+        args1.tdata()[0] = e1;
         args2.setDim(1);
-        args2.data[0] = (void*) e2;
+        args2.tdata()[0] = e2;
 
         Match m;
         memset(&m, 0, sizeof(m));
@@ -939,7 +939,7 @@ Expression *BinAssignExp::op_overload(Scope *sc)
                 Expressions *a = new Expressions();
                 a->push(e2);
                 for (int i = 0; i < ae->arguments->dim; i++)
-                    a->push(ae->arguments->data[i]);
+                    a->push(ae->arguments->tdata()[i]);
 
                 Objects *targsi = opToArg(sc, op);
                 Expression *e = new DotTemplateInstanceExp(loc, ae->e1, fd->ident, targsi);
@@ -1051,7 +1051,7 @@ Expression *BinAssignExp::op_overload(Scope *sc)
          */
 
         args2.setDim(1);
-        args2.data[0] = (void*) e2;
+        args2.tdata()[0] = e2;
 
         Match m;
         memset(&m, 0, sizeof(m));
@@ -1195,7 +1195,7 @@ void inferApplyArgTypes(enum TOK op, Parameters *arguments, Expression *aggr)
     for (size_t u = 0; 1; u++)
     {   if (u == arguments->dim)
             return;
-        Parameter *arg = (Parameter *)arguments->data[u];
+        Parameter *arg = arguments->tdata()[u];
         if (!arg->type)
             break;
     }
@@ -1203,7 +1203,7 @@ void inferApplyArgTypes(enum TOK op, Parameters *arguments, Expression *aggr)
     Dsymbol *s;
     AggregateDeclaration *ad;
 
-    Parameter *arg = (Parameter *)arguments->data[0];
+    Parameter *arg = arguments->tdata()[0];
     Type *taggr = aggr->type;
     if (!taggr)
         return;
@@ -1217,7 +1217,7 @@ void inferApplyArgTypes(enum TOK op, Parameters *arguments, Expression *aggr)
             {
                 if (!arg->type)
                     arg->type = Type::tsize_t;  // key type
-                arg = (Parameter *)arguments->data[1];
+                arg = arguments->tdata()[1];
             }
             if (!arg->type && tab->ty != Ttuple)
                 arg->type = tab->nextOf();      // value type
@@ -1230,7 +1230,7 @@ void inferApplyArgTypes(enum TOK op, Parameters *arguments, Expression *aggr)
             {
                 if (!arg->type)
                     arg->type = taa->index;     // key type
-                arg = (Parameter *)arguments->data[1];
+                arg = arguments->tdata()[1];
             }
             if (!arg->type)
                 arg->type = taa->next;          // value type
@@ -1366,7 +1366,7 @@ static int inferApplyArgTypesY(TypeFunction *tf, Parameters *arguments)
 
     for (size_t u = 0; u < nparams; u++)
     {
-        Parameter *arg = (Parameter *)arguments->data[u];
+        Parameter *arg = arguments->tdata()[u];
         Parameter *param = Parameter::getNth(tf->parameters, u);
         if (arg->type)
         {   if (!arg->type->equals(param->type))
@@ -1410,7 +1410,7 @@ void inferApplyArgTypesZ(TemplateDeclaration *tstart, Parameters *arguments)
         }
         if (!td->parameters || td->parameters->dim != 1)
             continue;
-        TemplateParameter *tp = (TemplateParameter *)td->parameters->data[0];
+        TemplateParameter *tp = td->parameters->tdata()[0];
         TemplateAliasParameter *tap = tp->isTemplateAliasParameter();
         if (!tap || !tap->specType || tap->specType->ty != Tfunction)
             continue;
diff --git a/src/optimize.c b/src/optimize.c
index b9948aa8aa88..4a59e6e71408 100644
--- a/src/optimize.c
+++ b/src/optimize.c
@@ -202,10 +202,10 @@ Expression *VarExp::optimize(int result)
 Expression *TupleExp::optimize(int result)
 {
     for (size_t i = 0; i < exps->dim; i++)
-    {   Expression *e = (Expression *)exps->data[i];
+    {   Expression *e = exps->tdata()[i];
 
         e = e->optimize(WANTvalue | (result & WANTinterpret));
-        exps->data[i] = (void *)e;
+        exps->tdata()[i] = e;
     }
     return this;
 }
@@ -215,10 +215,10 @@ Expression *ArrayLiteralExp::optimize(int result)
     if (elements)
     {
         for (size_t i = 0; i < elements->dim; i++)
-        {   Expression *e = (Expression *)elements->data[i];
+        {   Expression *e = elements->tdata()[i];
 
             e = e->optimize(WANTvalue | (result & (WANTinterpret | WANTexpand)));
-            elements->data[i] = (void *)e;
+            elements->tdata()[i] = e;
         }
     }
     return this;
@@ -228,14 +228,14 @@ Expression *AssocArrayLiteralExp::optimize(int result)
 {
     assert(keys->dim == values->dim);
     for (size_t i = 0; i < keys->dim; i++)
-    {   Expression *e = (Expression *)keys->data[i];
+    {   Expression *e = keys->tdata()[i];
 
         e = e->optimize(WANTvalue | (result & (WANTinterpret | WANTexpand)));
-        keys->data[i] = (void *)e;
+        keys->tdata()[i] = e;
 
-        e = (Expression *)values->data[i];
+        e = values->tdata()[i];
         e = e->optimize(WANTvalue | (result & (WANTinterpret | WANTexpand)));
-        values->data[i] = (void *)e;
+        values->tdata()[i] = e;
     }
     return this;
 }
@@ -245,11 +245,11 @@ Expression *StructLiteralExp::optimize(int result)
     if (elements)
     {
         for (size_t i = 0; i < elements->dim; i++)
-        {   Expression *e = (Expression *)elements->data[i];
+        {   Expression *e = elements->tdata()[i];
             if (!e)
                 continue;
             e = e->optimize(WANTvalue | (result & (WANTinterpret | WANTexpand)));
-            elements->data[i] = (void *)e;
+            elements->tdata()[i] = e;
         }
     }
     return this;
@@ -468,20 +468,20 @@ Expression *NewExp::optimize(int result)
     if (newargs)
     {
         for (size_t i = 0; i < newargs->dim; i++)
-        {   Expression *e = (Expression *)newargs->data[i];
+        {   Expression *e = newargs->tdata()[i];
 
             e = e->optimize(WANTvalue);
-            newargs->data[i] = (void *)e;
+            newargs->tdata()[i] = e;
         }
     }
 
     if (arguments)
     {
         for (size_t i = 0; i < arguments->dim; i++)
-        {   Expression *e = (Expression *)arguments->data[i];
+        {   Expression *e = arguments->tdata()[i];
 
             e = e->optimize(WANTvalue);
-            arguments->data[i] = (void *)e;
+            arguments->tdata()[i] = e;
         }
     }
     if (result & WANTinterpret)
@@ -500,10 +500,10 @@ Expression *CallExp::optimize(int result)
     if (arguments)
     {
         for (size_t i = 0; i < arguments->dim; i++)
-        {   Expression *e = (Expression *)arguments->data[i];
+        {   Expression *e = arguments->tdata()[i];
 
             e = e->optimize(WANTvalue);
-            arguments->data[i] = (void *)e;
+            arguments->tdata()[i] = e;
         }
     }
 
diff --git a/src/parse.c b/src/parse.c
index f803d5309f54..94e587087382 100644
--- a/src/parse.c
+++ b/src/parse.c
@@ -1984,7 +1984,7 @@ Objects *Parser::parseTemplateArgumentList2()
                          */
                         TemplateParameters *tpl = NULL;
                         for (int i = 0; i < tf->parameters->dim; i++)
-                        {   Parameter *param = (Parameter *)tf->parameters->data[i];
+                        {   Parameter *param = tf->parameters->tdata()[i];
                             if (param->ident == NULL &&
                                 param->type &&
                                 param->type->ty == Tident &&
@@ -3489,7 +3489,7 @@ Statement *Parser::parseStatement(int flags)
                 as->reserve(a->dim);
                 for (int i = 0; i < a->dim; i++)
                 {
-                    Dsymbol *d = (Dsymbol *)a->data[i];
+                    Dsymbol *d = a->tdata()[i];
                     s = new ExpStatement(loc, d);
                     as->push(s);
                 }
@@ -3497,7 +3497,7 @@ Statement *Parser::parseStatement(int flags)
             }
             else if (a->dim == 1)
             {
-                Dsymbol *d = (Dsymbol *)a->data[0];
+                Dsymbol *d = a->tdata()[0];
                 s = new ExpStatement(loc, d);
             }
             else
@@ -3707,7 +3707,7 @@ Statement *Parser::parseStatement(int flags)
             Expression *aggr = parseExpression();
             if (token.value == TOKslice && arguments->dim == 1)
             {
-                Parameter *a = (Parameter *)arguments->data[0];
+                Parameter *a = arguments->tdata()[0];
                 delete arguments;
                 nextToken();
                 Expression *upr = parseExpression();
@@ -3939,7 +3939,7 @@ Statement *Parser::parseStatement(int flags)
                 // Keep cases in order by building the case statements backwards
                 for (int i = cases.dim; i; i--)
                 {
-                    exp = (Expression *)cases.data[i - 1];
+                    exp = cases.tdata()[i - 1];
                     s = new CaseStatement(loc, exp, s);
                 }
             }
diff --git a/src/root/root.c b/src/root/root.c
index c6553da90cbd..f820fbbaccdc 100644
--- a/src/root/root.c
+++ b/src/root/root.c
@@ -804,7 +804,7 @@ char *FileName::searchPath(Strings *path, const char *name, int cwd)
 
         for (i = 0; i < path->dim; i++)
         {
-            char *p = (char *)path->data[i];
+            char *p = path->tdata()[i];
             char *n = combine(p, name);
 
             if (exists(n))
@@ -865,7 +865,7 @@ char *FileName::safeSearchPath(Strings *path, const char *name)
         for (i = 0; i < path->dim; i++)
         {
             char *cname = NULL;
-            char *cpath = canonicalName((char *)path->data[i]);
+            char *cpath = canonicalName(path->tdata()[i]);
             //printf("FileName::safeSearchPath(): name=%s; path=%s; cpath=%s\n",
             //      name, (char *)path->data[i], cpath);
             if (cpath == NULL)
@@ -1552,11 +1552,11 @@ OutBuffer::~OutBuffer()
     mem.free(data);
 }
 
-void *OutBuffer::extractData()
+char *OutBuffer::extractData()
 {
-    void *p;
+    char *p;
 
-    p = (void *)data;
+    p = (char *)data;
     data = NULL;
     offset = 0;
     size = 0;
diff --git a/src/root/root.h b/src/root/root.h
index 56965de6bc18..d71f54709b7c 100644
--- a/src/root/root.h
+++ b/src/root/root.h
@@ -271,7 +271,7 @@ struct OutBuffer : Object
 
     OutBuffer();
     ~OutBuffer();
-    void *extractData();
+    char *extractData();
     void mark();
 
     void reserve(unsigned nbytes);
@@ -314,7 +314,7 @@ struct OutBuffer : Object
 struct ArrayBase : Object
 {
     unsigned dim;
-  //protected:
+  protected:
     void **data;
 
   private:
@@ -336,7 +336,7 @@ struct ArrayBase : Object
     void *pop();
     void shift(void *ptr);
     void insert(unsigned index, void *ptr);
-  //protected:
+  protected:
     void insert(unsigned index, ArrayBase *a);
     void append(ArrayBase *a);
   public:
@@ -344,7 +344,7 @@ struct ArrayBase : Object
     void zero();
     void *tos();
     void sort();
-  //protected:
+  protected:
     ArrayBase *copy();
 };
 
diff --git a/src/s2ir.c b/src/s2ir.c
index 9f4ccfdbdb15..a9fe47bb3b6e 100644
--- a/src/s2ir.c
+++ b/src/s2ir.c
@@ -203,7 +203,7 @@ void PragmaStatement::toIR(IRState *irs)
     if (ident == Id::startaddress)
     {
         assert(args && args->dim == 1);
-        Expression *e = (Expression *)args->data[0];
+        Expression *e = args->tdata()[0];
         Dsymbol *sa = getDsymbol(e);
         FuncDeclaration *f = sa->isFuncDeclaration();
         assert(f);
@@ -869,7 +869,7 @@ void LabelStatement::toIR(IRState *irs)
         if (fwdrefs)
         {
             for (int i = 0; i < fwdrefs->dim; i++)
-            {   block *b = (block *)fwdrefs->data[i];
+            {   block *b = fwdrefs->tdata()[i];
 
                 if (b->Btry != lblock->Btry)
                 {
@@ -941,7 +941,7 @@ void SwitchStatement::toIR(IRState *irs)
         }
 
         for (int i = 0; i < numcases; i++)
-        {   CaseStatement *cs = (CaseStatement *)cases->data[i];
+        {   CaseStatement *cs = cases->tdata()[i];
 
             elem *ecase = cs->exp->toElem(&mystate);
             elem *e = el_bin(OPeqeq, TYbool, el_copytree(econd), ecase);
@@ -974,7 +974,7 @@ void SwitchStatement::toIR(IRState *irs)
     {
         // Number the cases so we can unscramble things after the sort()
         for (int i = 0; i < numcases; i++)
-        {   CaseStatement *cs = (CaseStatement *)cases->data[i];
+        {   CaseStatement *cs = cases->tdata()[i];
             cs->index = i;
         }
 
@@ -992,7 +992,7 @@ void SwitchStatement::toIR(IRState *irs)
         dtxoff(&dt, si, PTRSIZE * 2, TYnptr);
 
         for (int i = 0; i < numcases; i++)
-        {   CaseStatement *cs = (CaseStatement *)cases->data[i];
+        {   CaseStatement *cs = cases->tdata()[i];
 
             if (cs->exp->op != TOKstring)
             {   error("case '%s' is not a string", cs->exp->toChars()); // BUG: this should be an assert
@@ -1050,7 +1050,7 @@ void SwitchStatement::toIR(IRState *irs)
      */
     for (int i = 0; i < numcases; i++)
     {
-        CaseStatement *cs = (CaseStatement *)cases->data[i];
+        CaseStatement *cs = cases->tdata()[i];
         if (string)
         {
             pu[cs->index] = i;
@@ -1324,7 +1324,7 @@ void CompoundStatement::toIR(IRState *irs)
         size_t dim = statements->dim;
         for (size_t i = 0 ; i < dim ; i++)
         {
-            Statement *s = (Statement *)statements->data[i];
+            Statement *s = statements->tdata()[i];
             if (s != NULL)
             {
                 s->toIR(irs);
@@ -1355,7 +1355,7 @@ void UnrolledLoopStatement::toIR(IRState *irs)
     size_t dim = statements->dim;
     for (size_t i = 0 ; i < dim ; i++)
     {
-        Statement *s = (Statement *)statements->data[i];
+        Statement *s = statements->tdata()[i];
         if (s != NULL)
         {
             mystate.contBlock = block_calloc(blx);
@@ -1501,7 +1501,7 @@ void TryCatchStatement::toIR(IRState *irs)
     assert(catches);
     for (int i = 0 ; i < catches->dim; i++)
     {
-        Catch *cs = (Catch *)(catches->data[i]);
+        Catch *cs = catches->tdata()[i];
         if (cs->var)
             cs->var->csym = tryblock->jcatchvar;
         block *bcatch = blx->curblock;
diff --git a/src/statement.c b/src/statement.c
index f814d535e900..910234e19290 100644
--- a/src/statement.c
+++ b/src/statement.c
@@ -445,10 +445,10 @@ Statement *CompoundStatement::syntaxCopy()
     Statements *a = new Statements();
     a->setDim(statements->dim);
     for (size_t i = 0; i < statements->dim; i++)
-    {   Statement *s = (Statement *)statements->data[i];
+    {   Statement *s = statements->tdata()[i];
         if (s)
             s = s->syntaxCopy();
-        a->data[i] = s;
+        a->tdata()[i] = s;
     }
     CompoundStatement *cs = new CompoundStatement(loc, a);
     return cs;
@@ -463,7 +463,7 @@ Statement *CompoundStatement::semantic(Scope *sc)
 #if 0
     for (size_t i = 0; i < statements->dim; i++)
     {
-        s = (Statement *) statements->data[i];
+        s = statements->tdata()[i];
         if (s)
             printf("[%d]: %s", i, s->toChars());
     }
@@ -471,7 +471,7 @@ Statement *CompoundStatement::semantic(Scope *sc)
 
     for (size_t i = 0; i < statements->dim; )
     {
-        s = (Statement *) statements->data[i];
+        s = statements->tdata()[i];
         if (s)
         {   Statements *a = s->flatten(sc);
 
@@ -482,14 +482,14 @@ Statement *CompoundStatement::semantic(Scope *sc)
                 continue;
             }
             s = s->semantic(sc);
-            statements->data[i] = s;
+            statements->tdata()[i] = s;
             if (s)
             {
                 Statement *sentry;
                 Statement *sexception;
                 Statement *sfinally;
 
-                statements->data[i] = s->scopeCode(sc, &sentry, &sexception, &sfinally);
+                statements->tdata()[i] = s->scopeCode(sc, &sentry, &sexception, &sfinally);
                 if (sentry)
                 {
                     sentry = sentry->semantic(sc);
@@ -517,7 +517,7 @@ Statement *CompoundStatement::semantic(Scope *sc)
 
                         for (int j = i + 1; j < statements->dim; j++)
                         {
-                            a->push(statements->data[j]);
+                            a->push(statements->tdata()[j]);
                         }
                         body = new CompoundStatement(0, a);
                         body = new ScopeStatement(0, body);
@@ -558,7 +558,7 @@ Statement *CompoundStatement::semantic(Scope *sc)
 
                         for (int j = i + 1; j < statements->dim; j++)
                         {
-                            a->push(statements->data[j]);
+                            a->push(statements->tdata()[j]);
                         }
                         body = new CompoundStatement(0, a);
                         s = new TryFinallyStatement(0, body, sfinally);
@@ -574,7 +574,7 @@ Statement *CompoundStatement::semantic(Scope *sc)
     }
     if (statements->dim == 1)
     {
-        return (Statement *)statements->data[0];
+        return statements->tdata()[0];
     }
     return this;
 }
@@ -589,7 +589,7 @@ ReturnStatement *CompoundStatement::isReturnStatement()
     ReturnStatement *rs = NULL;
 
     for (int i = 0; i < statements->dim; i++)
-    {   Statement *s = (Statement *) statements->data[i];
+    {   Statement *s = statements->tdata()[i];
         if (s)
         {
             rs = s->isReturnStatement();
@@ -603,7 +603,7 @@ ReturnStatement *CompoundStatement::isReturnStatement()
 void CompoundStatement::toCBuffer(OutBuffer *buf, HdrGenState *hgs)
 {
     for (int i = 0; i < statements->dim; i++)
-    {   Statement *s = (Statement *) statements->data[i];
+    {   Statement *s = statements->tdata()[i];
         if (s)
             s->toCBuffer(buf, hgs);
     }
@@ -612,7 +612,7 @@ void CompoundStatement::toCBuffer(OutBuffer *buf, HdrGenState *hgs)
 int CompoundStatement::usesEH()
 {
     for (int i = 0; i < statements->dim; i++)
-    {   Statement *s = (Statement *) statements->data[i];
+    {   Statement *s = statements->tdata()[i];
         if (s && s->usesEH())
             return TRUE;
     }
@@ -624,7 +624,7 @@ int CompoundStatement::blockExit(bool mustNotThrow)
     //printf("CompoundStatement::blockExit(%p) %d\n", this, statements->dim);
     int result = BEfallthru;
     for (size_t i = 0; i < statements->dim; i++)
-    {   Statement *s = (Statement *) statements->data[i];
+    {   Statement *s = statements->tdata()[i];
         if (s)
         {
 //printf("result = x%x\n", result);
@@ -649,7 +649,7 @@ int CompoundStatement::comeFrom()
 
     //printf("CompoundStatement::comeFrom()\n");
     for (int i = 0; i < statements->dim; i++)
-    {   Statement *s = (Statement *)statements->data[i];
+    {   Statement *s = statements->tdata()[i];
 
         if (!s)
             continue;
@@ -662,7 +662,7 @@ int CompoundStatement::comeFrom()
 int CompoundStatement::isEmpty()
 {
     for (int i = 0; i < statements->dim; i++)
-    {   Statement *s = (Statement *) statements->data[i];
+    {   Statement *s = statements->tdata()[i];
         if (s && !s->isEmpty())
             return FALSE;
     }
@@ -683,10 +683,10 @@ Statement *CompoundDeclarationStatement::syntaxCopy()
     Statements *a = new Statements();
     a->setDim(statements->dim);
     for (size_t i = 0; i < statements->dim; i++)
-    {   Statement *s = (Statement *)statements->data[i];
+    {   Statement *s = statements->tdata()[i];
         if (s)
             s = s->syntaxCopy();
-        a->data[i] = s;
+        a->tdata()[i] = s;
     }
     CompoundDeclarationStatement *cs = new CompoundDeclarationStatement(loc, a);
     return cs;
@@ -696,7 +696,7 @@ void CompoundDeclarationStatement::toCBuffer(OutBuffer *buf, HdrGenState *hgs)
 {
     int nwritten = 0;
     for (int i = 0; i < statements->dim; i++)
-    {   Statement *s = (Statement *) statements->data[i];
+    {   Statement *s = statements->tdata()[i];
         ExpStatement *ds;
         if (s &&
             (ds = s->isExpStatement()) != NULL &&
@@ -760,10 +760,10 @@ Statement *UnrolledLoopStatement::syntaxCopy()
     Statements *a = new Statements();
     a->setDim(statements->dim);
     for (size_t i = 0; i < statements->dim; i++)
-    {   Statement *s = (Statement *)statements->data[i];
+    {   Statement *s = statements->tdata()[i];
         if (s)
             s = s->syntaxCopy();
-        a->data[i] = s;
+        a->tdata()[i] = s;
     }
     UnrolledLoopStatement *cs = new UnrolledLoopStatement(loc, a);
     return cs;
@@ -781,12 +781,12 @@ Statement *UnrolledLoopStatement::semantic(Scope *sc)
 
     for (size_t i = 0; i < statements->dim; i++)
     {
-        Statement *s = (Statement *) statements->data[i];
+        Statement *s = statements->tdata()[i];
         if (s)
         {
             //printf("[%d]: %s\n", i, s->toChars());
             s = s->semantic(scd);
-            statements->data[i] = s;
+            statements->tdata()[i] = s;
         }
     }
 
@@ -803,7 +803,7 @@ void UnrolledLoopStatement::toCBuffer(OutBuffer *buf, HdrGenState *hgs)
     for (size_t i = 0; i < statements->dim; i++)
     {   Statement *s;
 
-        s = (Statement *) statements->data[i];
+        s = statements->tdata()[i];
         if (s)
             s->toCBuffer(buf, hgs);
     }
@@ -825,7 +825,7 @@ int UnrolledLoopStatement::hasContinue()
 int UnrolledLoopStatement::usesEH()
 {
     for (size_t i = 0; i < statements->dim; i++)
-    {   Statement *s = (Statement *) statements->data[i];
+    {   Statement *s = statements->tdata()[i];
         if (s && s->usesEH())
             return TRUE;
     }
@@ -836,7 +836,7 @@ int UnrolledLoopStatement::blockExit(bool mustNotThrow)
 {
     int result = BEfallthru;
     for (size_t i = 0; i < statements->dim; i++)
-    {   Statement *s = (Statement *) statements->data[i];
+    {   Statement *s = statements->tdata()[i];
         if (s)
         {
             int r = s->blockExit(mustNotThrow);
@@ -852,7 +852,7 @@ int UnrolledLoopStatement::comeFrom()
 
     //printf("UnrolledLoopStatement::comeFrom()\n");
     for (size_t i = 0; i < statements->dim; i++)
-    {   Statement *s = (Statement *)statements->data[i];
+    {   Statement *s = statements->tdata()[i];
 
         if (!s)
             continue;
@@ -1396,10 +1396,10 @@ Statement *ForeachStatement::semantic(Scope *sc)
             Expression *e;
             Type *t;
             if (te)
-                e = (Expression *)te->exps->data[k];
+                e = te->exps->tdata()[k];
             else
                 t = Parameter::getNth(tuple->arguments, k)->type;
-            Parameter *arg = (Parameter *)arguments->data[0];
+            Parameter *arg = arguments->tdata()[0];
             Statements *st = new Statements();
 
             if (dim == 2)
@@ -1422,7 +1422,7 @@ Statement *ForeachStatement::semantic(Scope *sc)
                 var->storage_class |= STCmanifest;
                 DeclarationExp *de = new DeclarationExp(loc, var);
                 st->push(new ExpStatement(loc, de));
-                arg = (Parameter *)arguments->data[1];  // value
+                arg = arguments->tdata()[1];  // value
             }
             // Declare value
             if (arg->storageClass & (STCout | STCref | STClazy))
@@ -1493,7 +1493,7 @@ Statement *ForeachStatement::semantic(Scope *sc)
             {   Parameter *arg;
 
                 int i = (dim == 1) ? 0 : 1;     // index of value
-                arg = (Parameter *)arguments->data[i];
+                arg = arguments->tdata()[i];
                 arg->type = arg->type->semantic(loc, sc);
                 tnv = arg->type->toBasetype();
                 if (tnv->ty != tn->ty &&
@@ -1502,7 +1502,7 @@ Statement *ForeachStatement::semantic(Scope *sc)
                     if (arg->storageClass & STCref)
                         error("foreach: value of UTF conversion cannot be ref");
                     if (dim == 2)
-                    {   arg = (Parameter *)arguments->data[0];
+                    {   arg = arguments->tdata()[0];
                         if (arg->storageClass & STCref)
                             error("foreach: key cannot be ref");
                     }
@@ -1512,7 +1512,7 @@ Statement *ForeachStatement::semantic(Scope *sc)
 
             for (size_t i = 0; i < dim; i++)
             {   // Declare args
-                Parameter *arg = (Parameter *)arguments->data[i];
+                Parameter *arg = arguments->tdata()[i];
                 Type *argtype = arg->type->semantic(loc, sc);
                 VarDeclaration *var;
 
@@ -1717,7 +1717,7 @@ Statement *ForeachStatement::semantic(Scope *sc)
             e = new VarExp(loc, r);
             Expression *einit = new DotIdExp(loc, e, idhead);
 //          einit = einit->semantic(sc);
-            Parameter *arg = (Parameter *)arguments->data[0];
+            Parameter *arg = arguments->tdata()[0];
             VarDeclaration *ve = new VarDeclaration(loc, arg->type, arg->ident, new ExpInitializer(loc, einit));
             ve->storage_class |= STCforeach;
             ve->storage_class |= arg->storageClass & (STCin | STCout | STCref | STC_TYPECTOR);
@@ -1769,7 +1769,7 @@ Statement *ForeachStatement::semantic(Scope *sc)
              */
             Parameters *args = new Parameters();
             for (size_t i = 0; i < dim; i++)
-            {   Parameter *arg = (Parameter *)arguments->data[i];
+            {   Parameter *arg = arguments->tdata()[i];
                 Identifier *id;
 
                 arg->type = arg->type->semantic(loc, sc);
@@ -1789,7 +1789,7 @@ Statement *ForeachStatement::semantic(Scope *sc)
                 args->push(a);
             }
             Type *t = new TypeFunction(args, Type::tint32, 0, LINKd);
-            cases = new CaseStatements();
+            cases = new Statements();
             gotos = new CompoundStatements();
             FuncLiteralDeclaration *fld = new FuncLiteralDeclaration(loc, 0, t, TOKdelegate, this);
             fld->fbody = body;
@@ -1799,28 +1799,28 @@ Statement *ForeachStatement::semantic(Scope *sc)
 
             // Resolve any forward referenced goto's
             for (size_t i = 0; i < gotos->dim; i++)
-            {   CompoundStatement *cs = (CompoundStatement *)gotos->data[i];
-                GotoStatement *gs = (GotoStatement *)cs->statements->data[0];
+            {   CompoundStatement *cs = gotos->tdata()[i];
+                GotoStatement *gs = (GotoStatement *)cs->statements->tdata()[0];
 
                 if (!gs->label->statement)
                 {   // 'Promote' it to this scope, and replace with a return
                     cases->push(gs);
                     s = new ReturnStatement(0, new IntegerExp(cases->dim + 1));
-                    cs->statements->data[0] = (void *)s;
+                    cs->statements->tdata()[0] = s;
                 }
             }
 
             if (tab->ty == Taarray)
             {
                 // Check types
-                Parameter *arg = (Parameter *)arguments->data[0];
+                Parameter *arg = arguments->tdata()[0];
                 if (dim == 2)
                 {
                     if (arg->storageClass & STCref)
                         error("foreach: index cannot be ref");
                     if (!arg->type->equals(taa->index))
                         error("foreach: index must be type %s, not %s", taa->index->toChars(), arg->type->toChars());
-                    arg = (Parameter *)arguments->data[1];
+                    arg = arguments->tdata()[1];
                 }
                 if (!arg->type->equals(taa->nextOf()))
                     error("foreach: value must be type %s, not %s", taa->nextOf()->toChars(), arg->type->toChars());
@@ -1949,7 +1949,7 @@ Statement *ForeachStatement::semantic(Scope *sc)
                 // cases 2...
                 for (int i = 0; i < cases->dim; i++)
                 {
-                    s = (Statement *)cases->data[i];
+                    s = cases->tdata()[i];
                     s = new CaseStatement(0, new IntegerExp(i + 2), s);
                     a->push(s);
                 }
@@ -1978,7 +1978,7 @@ bool ForeachStatement::checkForArgTypes()
 {   bool result = TRUE;
 
     for (size_t i = 0; i < arguments->dim; i++)
-    {   Parameter *arg = (Parameter *)arguments->data[i];
+    {   Parameter *arg = arguments->tdata()[i];
         if (!arg->type)
         {
             error("cannot infer type for %s", arg->ident->toChars());
@@ -2031,7 +2031,7 @@ void ForeachStatement::toCBuffer(OutBuffer *buf, HdrGenState *hgs)
     buf->writestring(" (");
     for (int i = 0; i < arguments->dim; i++)
     {
-        Parameter *a = (Parameter *)arguments->data[i];
+        Parameter *a = arguments->tdata()[i];
         if (i)
             buf->writestring(", ");
         if (a->storageClass & STCref)
@@ -2574,7 +2574,7 @@ Statement *PragmaStatement::semantic(Scope *sc)
         {
             for (size_t i = 0; i < args->dim; i++)
             {
-                Expression *e = (Expression *)args->data[i];
+                Expression *e = args->tdata()[i];
 
                 e = e->semantic(sc);
                 e = e->optimize(WANTvalue | WANTinterpret);
@@ -2600,11 +2600,11 @@ Statement *PragmaStatement::semantic(Scope *sc)
             error("string expected for library name");
         else
         {
-            Expression *e = (Expression *)args->data[0];
+            Expression *e = args->tdata()[0];
 
             e = e->semantic(sc);
             e = e->optimize(WANTvalue | WANTinterpret);
-            args->data[0] = (void *)e;
+            args->tdata()[0] = e;
             if (e->op != TOKstring)
                 error("string expected for library name, not '%s'", e->toChars());
             else if (global.params.verbose)
@@ -2626,10 +2626,10 @@ Statement *PragmaStatement::semantic(Scope *sc)
             error("function name expected for start address");
         else
         {
-            Expression *e = (Expression *)args->data[0];
+            Expression *e = args->tdata()[0];
             e = e->semantic(sc);
             e = e->optimize(WANTvalue | WANTinterpret);
-            args->data[0] = (void *)e;
+            args->tdata()[0] = e;
             Dsymbol *sa = getDsymbol(e);
             if (!sa || !sa->isFuncDeclaration())
                 error("function name expected for start address, not '%s'", e->toChars());
@@ -2785,7 +2785,7 @@ Statement *SwitchStatement::semantic(Scope *sc)
     // Resolve any goto case's with exp
     for (int i = 0; i < gotoCases.dim; i++)
     {
-        GotoCaseStatement *gcs = (GotoCaseStatement *)gotoCases.data[i];
+        GotoCaseStatement *gcs = gotoCases.tdata()[i];
 
         if (!gcs->exp)
         {
@@ -2799,7 +2799,7 @@ Statement *SwitchStatement::semantic(Scope *sc)
                 continue;
             for (int j = 0; j < scx->sw->cases->dim; j++)
             {
-                CaseStatement *cs = (CaseStatement *)scx->sw->cases->data[j];
+                CaseStatement *cs = scx->sw->cases->tdata()[j];
 
                 if (cs->exp->equals(gcs->exp))
                 {
@@ -2854,11 +2854,11 @@ Statement *SwitchStatement::semantic(Scope *sc)
             size_t dim = ed->members->dim;
             for (size_t i = 0; i < dim; i++)
             {
-                EnumMember *em = ((Dsymbol *)ed->members->data[i])->isEnumMember();
+                EnumMember *em = ed->members->tdata()[i]->isEnumMember();
                 if (em)
                 {
                     for (size_t j = 0; j < cases->dim; j++)
-                    {   CaseStatement *cs = (CaseStatement *)cases->data[j];
+                    {   CaseStatement *cs = cases->tdata()[j];
                         if (cs->exp->equals(em->value))
                             goto L1;
                     }
@@ -2981,7 +2981,7 @@ Statement *CaseStatement::semantic(Scope *sc)
     L1:
         for (int i = 0; i < sw->cases->dim; i++)
         {
-            CaseStatement *cs = (CaseStatement *)sw->cases->data[i];
+            CaseStatement *cs = sw->cases->tdata()[i];
 
             //printf("comparing '%s' with '%s'\n", exp->toChars(), cs->exp->toChars());
             if (cs->exp->equals(exp))
@@ -2995,7 +2995,7 @@ Statement *CaseStatement::semantic(Scope *sc)
         // Resolve any goto case's with no exp to this case statement
         for (int i = 0; i < sw->gotoCases.dim; i++)
         {
-            GotoCaseStatement *gcs = (GotoCaseStatement *)sw->gotoCases.data[i];
+            GotoCaseStatement *gcs = sw->gotoCases.tdata()[i];
 
             if (!gcs->exp)
             {
@@ -4103,9 +4103,9 @@ Statement *TryCatchStatement::syntaxCopy()
     for (int i = 0; i < a->dim; i++)
     {   Catch *c;
 
-        c = (Catch *)catches->data[i];
+        c = catches->tdata()[i];
         c = c->syntaxCopy();
-        a->data[i] = c;
+        a->tdata()[i] = c;
     }
     TryCatchStatement *s = new TryCatchStatement(loc, body->syntaxCopy(), a);
     return s;
@@ -4118,12 +4118,12 @@ Statement *TryCatchStatement::semantic(Scope *sc)
     /* Even if body is NULL, still do semantic analysis on catches
      */
     for (size_t i = 0; i < catches->dim; i++)
-    {   Catch *c = (Catch *)catches->data[i];
+    {   Catch *c = catches->tdata()[i];
         c->semantic(sc);
 
         // Determine if current catch 'hides' any previous catches
         for (size_t j = 0; j < i; j++)
-        {   Catch *cj = (Catch *)catches->data[j];
+        {   Catch *cj = catches->tdata()[j];
             char *si = c->loc.toChars();
             char *sj = cj->loc.toChars();
 
@@ -4157,7 +4157,7 @@ int TryCatchStatement::blockExit(bool mustNotThrow)
     int catchresult = 0;
     for (size_t i = 0; i < catches->dim; i++)
     {
-        Catch *c = (Catch *)catches->data[i];
+        Catch *c = catches->tdata()[i];
         if (c->type == Type::terror)
             continue;
 
@@ -4188,7 +4188,7 @@ void TryCatchStatement::toCBuffer(OutBuffer *buf, HdrGenState *hgs)
         body->toCBuffer(buf, hgs);
     for (size_t i = 0; i < catches->dim; i++)
     {
-        Catch *c = (Catch *)catches->data[i];
+        Catch *c = catches->tdata()[i];
         c->toCBuffer(buf, hgs);
     }
 }
@@ -4518,10 +4518,10 @@ Statements *VolatileStatement::flatten(Scope *sc)
     a = statement ? statement->flatten(sc) : NULL;
     if (a)
     {   for (int i = 0; i < a->dim; i++)
-        {   Statement *s = (Statement *)a->data[i];
+        {   Statement *s = a->tdata()[i];
 
             s = new VolatileStatement(loc, s);
-            a->data[i] = s;
+            a->tdata()[i] = s;
         }
     }
 
@@ -4579,10 +4579,10 @@ Statements *DebugStatement::flatten(Scope *sc)
     Statements *a = statement ? statement->flatten(sc) : NULL;
     if (a)
     {   for (size_t i = 0; i < a->dim; i++)
-        {   Statement *s = (Statement *)a->data[i];
+        {   Statement *s = a->tdata()[i];
 
             s = new DebugStatement(loc, s);
-            a->data[i] = s;
+            a->tdata()[i] = s;
         }
     }
 
@@ -4629,7 +4629,7 @@ Statement *GotoStatement::semantic(Scope *sc)
          * list.
          */
         Statements *a = new Statements();
-        Statement *s;
+        CompoundStatement *s;
 
         a->push(this);
         s = new CompoundStatement(loc, a);
@@ -4708,10 +4708,10 @@ Statements *LabelStatement::flatten(Scope *sc)
             {
                 a->push(new ExpStatement(loc, (Expression *)NULL));
             }
-            Statement *s = (Statement *)a->data[0];
+            Statement *s = a->tdata()[0];
 
             s = new LabelStatement(loc, ident, s);
-            a->data[0] = s;
+            a->tdata()[0] = s;
         }
     }
 
diff --git a/src/statement.h b/src/statement.h
index 937a13b9bc3c..71ad02cafe67 100644
--- a/src/statement.h
+++ b/src/statement.h
@@ -322,7 +322,7 @@ struct ForeachStatement : Statement
 
     FuncDeclaration *func;      // function we're lexically in
 
-    CaseStatements *cases;      // put breaks, continues, gotos and returns here
+    Statements *cases;          // put breaks, continues, gotos and returns here
     CompoundStatements *gotos;  // forward referenced goto's go here
 
     ForeachStatement(Loc loc, enum TOK op, Parameters *arguments, Expression *aggr, Statement *body);
diff --git a/src/struct.c b/src/struct.c
index fe614b3e4fb3..f48ae77e27a6 100644
--- a/src/struct.c
+++ b/src/struct.c
@@ -72,7 +72,7 @@ void AggregateDeclaration::semantic2(Scope *sc)
         sc = sc->push(this);
         for (size_t i = 0; i < members->dim; i++)
         {
-            Dsymbol *s = (Dsymbol *)members->data[i];
+            Dsymbol *s = members->tdata()[i];
             s->semantic2(sc);
         }
         sc->pop();
@@ -88,7 +88,7 @@ void AggregateDeclaration::semantic3(Scope *sc)
         sc = sc->push(this);
         for (i = 0; i < members->dim; i++)
         {
-            Dsymbol *s = (Dsymbol *)members->data[i];
+            Dsymbol *s = members->tdata()[i];
             s->semantic3(sc);
         }
         sc->pop();
@@ -103,7 +103,7 @@ void AggregateDeclaration::inlineScan()
     {
         for (i = 0; i < members->dim; i++)
         {
-            Dsymbol *s = (Dsymbol *)members->data[i];
+            Dsymbol *s = members->tdata()[i];
             //printf("inline scan aggregate symbol '%s'\n", s->toChars());
             s->inlineScan();
         }
@@ -247,13 +247,13 @@ int AggregateDeclaration::firstFieldInUnion(int indx)
 {
     if (isUnionDeclaration())
         return 0;
-    VarDeclaration * vd = (VarDeclaration *)fields.data[indx];
+    VarDeclaration * vd = fields.tdata()[indx];
     int firstNonZero = indx; // first index in the union with non-zero size
     for (; ;)
     {
         if (indx == 0)
             return firstNonZero;
-        VarDeclaration * v = (VarDeclaration *)fields.data[indx - 1];
+        VarDeclaration * v = fields.tdata()[indx - 1];
         if (v->offset != vd->offset)
             return firstNonZero;
         --indx;
@@ -272,7 +272,7 @@ int AggregateDeclaration::firstFieldInUnion(int indx)
  */
 int AggregateDeclaration::numFieldsInUnion(int firstIndex)
 {
-    VarDeclaration * vd = (VarDeclaration *)fields.data[firstIndex];
+    VarDeclaration * vd = fields.tdata()[firstIndex];
     /* If it is a zero-length field, AND we can't find an earlier non-zero
      * sized field with the same offset, we assume it's not part of a union.
      */
@@ -282,7 +282,7 @@ int AggregateDeclaration::numFieldsInUnion(int firstIndex)
     int count = 1;
     for (int i = firstIndex+1; i < fields.dim; ++i)
     {
-        VarDeclaration * v = (VarDeclaration *)fields.data[i];
+        VarDeclaration * v = fields.tdata()[i];
         // If offsets are different, they are not in the same union
         if (v->offset != vd->offset)
             break;
@@ -380,7 +380,7 @@ void StructDeclaration::semantic(Scope *sc)
         int hasfunctions = 0;
         for (int i = 0; i < members->dim; i++)
         {
-            Dsymbol *s = (Dsymbol *)members->data[i];
+            Dsymbol *s = members->tdata()[i];
             //printf("adding member '%s' to '%s'\n", s->toChars(), this->toChars());
             s->addMember(sc, this, 1);
             if (s->isFuncDeclaration())
@@ -436,7 +436,7 @@ void StructDeclaration::semantic(Scope *sc)
      * resolve individual members like enums.
      */
     for (int i = 0; i < members_dim; i++)
-    {   Dsymbol *s = (Dsymbol *)members->data[i];
+    {   Dsymbol *s = members->tdata()[i];
         /* There are problems doing this in the general case because
          * Scope keeps track of things like 'offset'
          */
@@ -449,7 +449,7 @@ void StructDeclaration::semantic(Scope *sc)
 
     for (int i = 0; i < members_dim; i++)
     {
-        Dsymbol *s = (Dsymbol *)members->data[i];
+        Dsymbol *s = members->tdata()[i];
         s->semantic(sc2);
 #if 0
         if (sizeok == 2)
@@ -616,7 +616,7 @@ void StructDeclaration::semantic(Scope *sc)
     zeroInit = 1;
     for (int i = 0; i < fields.dim; i++)
     {
-        Dsymbol *s = (Dsymbol *)fields.data[i];
+        Dsymbol *s = fields.tdata()[i];
         VarDeclaration *vd = s->isVarDeclaration();
         if (vd && !vd->isDataseg())
         {
@@ -686,7 +686,7 @@ void StructDeclaration::toCBuffer(OutBuffer *buf, HdrGenState *hgs)
     buf->writenl();
     for (i = 0; i < members->dim; i++)
     {
-        Dsymbol *s = (Dsymbol *)members->data[i];
+        Dsymbol *s = members->tdata()[i];
 
         buf->writestring("    ");
         s->toCBuffer(buf, hgs);
diff --git a/src/template.c b/src/template.c
index 6f9a68e27e70..31e6305e94b0 100644
--- a/src/template.c
+++ b/src/template.c
@@ -100,7 +100,7 @@ int arrayObjectIsError(Objects *args)
 {
     for (size_t i = 0; i < args->dim; i++)
     {
-        Object *o = (Object *)args->data[i];
+        Object *o = args->tdata()[i];
         if (isError(o))
             return 1;
     }
@@ -248,8 +248,8 @@ int match(Object *o1, Object *o2, TemplateDeclaration *tempdecl, Scope *sc)
             goto Lnomatch;
         for (size_t i = 0; i < v1->objects.dim; i++)
         {
-            if (!match((Object *)v1->objects.data[i],
-                       (Object *)v2->objects.data[i],
+            if (!match(v1->objects.tdata()[i],
+                       v2->objects.tdata()[i],
                        tempdecl, sc))
                 goto Lnomatch;
         }
@@ -273,8 +273,8 @@ int arrayObjectMatch(Objects *oa1, Objects *oa2, TemplateDeclaration *tempdecl,
     if (oa1->dim != oa2->dim)
         return 0;
     for (size_t j = 0; j < oa1->dim; j++)
-    {   Object *o1 = (Object *)oa1->data[j];
-        Object *o2 = (Object *)oa2->data[j];
+    {   Object *o1 = oa1->tdata()[j];
+        Object *o2 = oa2->tdata()[j];
         if (!match(o1, o2, tempdecl, sc))
         {
             return 0;
@@ -311,7 +311,7 @@ void ObjectToCBuffer(OutBuffer *buf, HdrGenState *hgs, Object *oarg)
         {
             if (i)
                 buf->writeByte(',');
-            Object *o = (Object *)args->data[i];
+            Object *o = args->tdata()[i];
             ObjectToCBuffer(buf, hgs, o);
         }
     }
@@ -356,7 +356,7 @@ TemplateDeclaration::TemplateDeclaration(Loc loc, Identifier *id,
 #if 0
     if (parameters)
         for (int i = 0; i < parameters->dim; i++)
-        {   TemplateParameter *tp = (TemplateParameter *)parameters->data[i];
+        {   TemplateParameter *tp = parameters->tdata()[i];
             //printf("\tparameter[%d] = %p\n", i, tp);
             TemplateTypeParameter *ttp = tp->isTemplateTypeParameter();
 
@@ -392,8 +392,8 @@ Dsymbol *TemplateDeclaration::syntaxCopy(Dsymbol *)
         p = new TemplateParameters();
         p->setDim(parameters->dim);
         for (int i = 0; i < p->dim; i++)
-        {   TemplateParameter *tp = (TemplateParameter *)parameters->data[i];
-            p->data[i] = (void *)tp->syntaxCopy();
+        {   TemplateParameter *tp = parameters->tdata()[i];
+            p->tdata()[i] = tp->syntaxCopy();
         }
     }
     Expression *e = NULL;
@@ -471,21 +471,21 @@ void TemplateDeclaration::semantic(Scope *sc)
         origParameters->setDim(parameters->dim);
         for (int i = 0; i < parameters->dim; i++)
         {
-            TemplateParameter *tp = (TemplateParameter *)parameters->data[i];
-            origParameters->data[i] = (void *)tp->syntaxCopy();
+            TemplateParameter *tp = parameters->tdata()[i];
+            origParameters->tdata()[i] = tp->syntaxCopy();
         }
     }
 
     for (int i = 0; i < parameters->dim; i++)
     {
-        TemplateParameter *tp = (TemplateParameter *)parameters->data[i];
+        TemplateParameter *tp = parameters->tdata()[i];
 
         tp->declareParameter(paramscope);
     }
 
     for (int i = 0; i < parameters->dim; i++)
     {
-        TemplateParameter *tp = (TemplateParameter *)parameters->data[i];
+        TemplateParameter *tp = parameters->tdata()[i];
 
         tp->semantic(paramscope);
         if (i + 1 != parameters->dim && tp->isTemplateTupleParameter())
@@ -548,8 +548,8 @@ int TemplateDeclaration::overloadInsert(Dsymbol *s)
             goto Lcontinue;
 
         for (int i = 0; i < f->parameters->dim; i++)
-        {   TemplateParameter *p1 = (TemplateParameter *)f->parameters->data[i];
-            TemplateParameter *p2 = (TemplateParameter *)f2->parameters->data[i];
+        {   TemplateParameter *p1 = f->parameters->tdata()[i];
+            TemplateParameter *p2 = f2->parameters->tdata()[i];
 
             if (!p1->overloadMatch(p2))
                 goto Lcontinue;
@@ -643,7 +643,7 @@ MATCH TemplateDeclaration::matchWithInstance(TemplateInstance *ti,
     if (ti->tiargs->dim)
         printf("ti->tiargs->dim = %d, [0] = %p\n",
             ti->tiargs->dim,
-            ti->tiargs->data[0]);
+            ti->tiargs->tdata()[0]);
 #endif
     dedtypes->zero();
 
@@ -673,7 +673,7 @@ MATCH TemplateDeclaration::matchWithInstance(TemplateInstance *ti,
     m = MATCHexact;
     for (int i = 0; i < dedtypes_dim; i++)
     {   MATCH m2;
-        TemplateParameter *tp = (TemplateParameter *)parameters->data[i];
+        TemplateParameter *tp = parameters->tdata()[i];
         Declaration *sparam;
 
         //printf("\targument [%d]\n", i);
@@ -716,9 +716,9 @@ MATCH TemplateDeclaration::matchWithInstance(TemplateInstance *ti,
          */
         for (int i = 0; i < dedtypes_dim; i++)
         {
-            if (!dedtypes->data[i])
+            if (!dedtypes->tdata()[i])
             {   assert(i < ti->tiargs->dim);
-                dedtypes->data[i] = ti->tiargs->data[i];
+                dedtypes->tdata()[i] = (Type *)ti->tiargs->tdata()[i];
             }
         }
     }
@@ -754,16 +754,16 @@ MATCH TemplateDeclaration::matchWithInstance(TemplateInstance *ti,
     {
         for (int i = 0; i < dedtypes_dim; i++)
         {
-            TemplateParameter *tp = (TemplateParameter *)parameters->data[i];
+            TemplateParameter *tp = parameters->tdata()[i];
             Object *oarg;
 
             printf(" [%d]", i);
 
             if (i < ti->tiargs->dim)
-                oarg = (Object *)ti->tiargs->data[i];
+                oarg = ti->tiargs->tdata()[i];
             else
                 oarg = NULL;
-            tp->print(oarg, (Object *)dedtypes->data[i]);
+            tp->print(oarg, dedtypes->tdata()[i]);
         }
     }
     else
@@ -820,11 +820,11 @@ MATCH TemplateDeclaration::leastAsSpecialized(TemplateDeclaration *td2)
     ti.tiargs->setDim(parameters->dim);
     for (int i = 0; i < ti.tiargs->dim; i++)
     {
-        TemplateParameter *tp = (TemplateParameter *)parameters->data[i];
+        TemplateParameter *tp = parameters->tdata()[i];
 
-        void *p = tp->dummyArg();
+        Object *p = (Object *)tp->dummyArg();
         if (p)
-            ti.tiargs->data[i] = p;
+            ti.tiargs->tdata()[i] = p;
         else
             ti.tiargs->setDim(i);
     }
@@ -888,7 +888,7 @@ MATCH TemplateDeclaration::deduceFunctionTemplateMatch(Scope *sc, Loc loc, Objec
 #if 0
     printf("\nTemplateDeclaration::deduceFunctionTemplateMatch() %s\n", toChars());
     for (i = 0; i < fargs->dim; i++)
-    {   Expression *e = (Expression *)fargs->data[i];
+    {   Expression *e = fargs->tdata()[i];
         printf("\tfarg[%d] is %s, type is %s\n", i, e->toChars(), e->type->toChars());
     }
     printf("fd = %s\n", fd->toChars());
@@ -918,7 +918,7 @@ MATCH TemplateDeclaration::deduceFunctionTemplateMatch(Scope *sc, Loc loc, Objec
     for (i = 0; i < dedargs->dim; i++)
     {
         printf("\tdedarg[%d] = ", i);
-        Object *oarg = (Object *)dedargs->data[i];
+        Object *oarg = dedargs->tdata()[i];
         if (oarg) printf("%s", oarg->toChars());
         printf("\n");
     }
@@ -942,13 +942,13 @@ MATCH TemplateDeclaration::deduceFunctionTemplateMatch(Scope *sc, Loc loc, Objec
              */
             Tuple *t = new Tuple();
             assert(parameters->dim);
-            dedargs->data[parameters->dim - 1] = (void *)t;
+            dedargs->tdata()[parameters->dim - 1] = t;
 
             tuple_dim = nargsi - n;
             t->objects.setDim(tuple_dim);
             for (size_t i = 0; i < tuple_dim; i++)
             {
-                t->objects.data[i] = (void *)targsi->data[n + i];
+                t->objects.tdata()[i] = targsi->tdata()[n + i];
             }
             declareParameter(paramscope, tp, t);
             tp_is_declared = 1;
@@ -956,11 +956,11 @@ MATCH TemplateDeclaration::deduceFunctionTemplateMatch(Scope *sc, Loc loc, Objec
         else
             n = nargsi;
 
-        memcpy(dedargs->data, targsi->data, n * sizeof(*dedargs->data));
+        memcpy(dedargs->tdata(), targsi->tdata(), n * sizeof(*dedargs->tdata()));
 
         for (size_t i = 0; i < n; i++)
         {   assert(i < parameters->dim);
-            TemplateParameter *tp = (TemplateParameter *)parameters->data[i];
+            TemplateParameter *tp = parameters->tdata()[i];
             MATCH m;
             Declaration *sparam = NULL;
 
@@ -980,7 +980,7 @@ MATCH TemplateDeclaration::deduceFunctionTemplateMatch(Scope *sc, Loc loc, Objec
     for (i = 0; i < dedargs->dim; i++)
     {
         printf("\tdedarg[%d] = ", i);
-        Object *oarg = (Object *)dedargs->data[i];
+        Object *oarg = dedargs->tdata()[i];
         if (oarg) printf("%s", oarg->toChars());
         printf("\n");
     }
@@ -1004,7 +1004,7 @@ MATCH TemplateDeclaration::deduceFunctionTemplateMatch(Scope *sc, Loc loc, Objec
                 goto L2;
             Tuple *t = new Tuple();
             //printf("t = %p\n", t);
-            dedargs->data[parameters->dim - 1] = (void *)t;
+            dedargs->tdata()[parameters->dim - 1] = t;
             declareParameter(paramscope, tp, t);
             goto L2;
         }
@@ -1019,7 +1019,7 @@ MATCH TemplateDeclaration::deduceFunctionTemplateMatch(Scope *sc, Loc loc, Objec
              */
             for (fptupindex = 0; fptupindex < nfparams; fptupindex++)
             {
-                Parameter *fparam = (Parameter *)fparameters->data[fptupindex];
+                Parameter *fparam = fparameters->tdata()[fptupindex];
                 if (fparam->type->ty != Tident)
                     continue;
                 TypeIdentifier *tid = (TypeIdentifier *)fparam->type;
@@ -1036,13 +1036,13 @@ MATCH TemplateDeclaration::deduceFunctionTemplateMatch(Scope *sc, Loc loc, Objec
                  * now form the tuple argument.
                  */
                 Tuple *t = new Tuple();
-                dedargs->data[parameters->dim - 1] = (void *)t;
+                dedargs->tdata()[parameters->dim - 1] = t;
 
                 tuple_dim = nfargs - (nfparams - 1);
                 t->objects.setDim(tuple_dim);
                 for (i = 0; i < tuple_dim; i++)
-                {   Expression *farg = (Expression *)fargs->data[fptupindex + i];
-                    t->objects.data[i] = (void *)farg->type;
+                {   Expression *farg = fargs->tdata()[fptupindex + i];
+                    t->objects.tdata()[i] = farg->type;
                 }
                 declareParameter(paramscope, tp, t);
                 goto L2;
@@ -1067,7 +1067,7 @@ MATCH TemplateDeclaration::deduceFunctionTemplateMatch(Scope *sc, Loc loc, Objec
     {
         // Match 'ethis' to any TemplateThisParameter's
         for (size_t i = 0; i < parameters->dim; i++)
-        {   TemplateParameter *tp = (TemplateParameter *)parameters->data[i];
+        {   TemplateParameter *tp = parameters->tdata()[i];
             TemplateThisParameter *ttp = tp->isTemplateThisParameter();
             if (ttp)
             {   MATCH m;
@@ -1151,7 +1151,7 @@ MATCH TemplateDeclaration::deduceFunctionTemplateMatch(Scope *sc, Loc loc, Objec
             }
         }
         else
-        {   Expression *farg = (Expression *)fargs->data[i];
+        {   Expression *farg = fargs->tdata()[i];
 #if 0
             printf("\tfarg->type   = %s\n", farg->type->toChars());
             printf("\tfparam->type = %s\n", fparam->type->toChars());
@@ -1222,7 +1222,7 @@ MATCH TemplateDeclaration::deduceFunctionTemplateMatch(Scope *sc, Loc loc, Objec
             {   TypeArray *ta = (TypeArray *)tb;
                 for (; i < nfargs; i++)
                 {
-                    Expression *arg = (Expression *)fargs->data[i];
+                    Expression *arg = fargs->tdata()[i];
                     assert(arg);
                     MATCH m;
                     /* If lazy array of delegates,
@@ -1269,13 +1269,13 @@ MATCH TemplateDeclaration::deduceFunctionTemplateMatch(Scope *sc, Loc loc, Objec
 
     for (i = nargsi; i < dedargs->dim; i++)
     {
-        TemplateParameter *tparam = (TemplateParameter *)parameters->data[i];
+        TemplateParameter *tparam = parameters->tdata()[i];
         //printf("tparam[%d] = %s\n", i, tparam->ident->toChars());
         /* For T:T*, the dedargs is the T*, dedtypes is the T
          * But for function templates, we really need them to match
          */
-        Object *oarg = (Object *)dedargs->data[i];
-        Object *oded = (Object *)dedtypes.data[i];
+        Object *oarg = dedargs->tdata()[i];
+        Object *oded = dedtypes.tdata()[i];
         //printf("1dedargs[%d] = %p, dedtypes[%d] = %p\n", i, oarg, i, oded);
         //if (oarg) printf("oarg: %s\n", oarg->toChars());
         //if (oded) printf("oded: %s\n", oded->toChars());
@@ -1288,14 +1288,14 @@ MATCH TemplateDeclaration::deduceFunctionTemplateMatch(Scope *sc, Loc loc, Objec
                      * the oded == oarg
                      */
                     Declaration *sparam;
-                    dedargs->data[i] = (void *)oded;
+                    dedargs->tdata()[i] = oded;
                     MATCH m2 = tparam->matchArg(paramscope, dedargs, i, parameters, &dedtypes, &sparam, 0);
                     //printf("m2 = %d\n", m2);
                     if (!m2)
                         goto Lnomatch;
                     if (m2 < match)
                         match = m2;             // pick worst match
-                    if (dedtypes.data[i] != oded)
+                    if (dedtypes.tdata()[i] != oded)
                         error("specialization not allowed for deduced parameter %s", tparam->ident->toChars());
                 }
             }
@@ -1314,7 +1314,7 @@ MATCH TemplateDeclaration::deduceFunctionTemplateMatch(Scope *sc, Loc loc, Objec
                 }
             }
             declareParameter(paramscope, tparam, oded);
-            dedargs->data[i] = (void *)oded;
+            dedargs->tdata()[i] = oded;
         }
     }
 
@@ -1380,7 +1380,7 @@ MATCH TemplateDeclaration::deduceFunctionTemplateMatch(Scope *sc, Loc loc, Objec
 
 #if 0
     for (i = 0; i < dedargs->dim; i++)
-    {   Type *t = (Type *)dedargs->data[i];
+    {   Type *t = dedargs->tdata()[i];
         printf("\tdedargs[%d] = %d, %s\n", i, t->dyncast(), t->toChars());
     }
 #endif
@@ -1474,7 +1474,7 @@ TemplateTupleParameter *isVariadic(TemplateParameters *parameters)
     TemplateTupleParameter *tp = NULL;
 
     if (dim)
-        tp = ((TemplateParameter *)parameters->data[dim - 1])->isTemplateTupleParameter();
+        tp = (parameters->tdata()[dim - 1])->isTemplateTupleParameter();
     return tp;
 }
 
@@ -1520,13 +1520,13 @@ FuncDeclaration *TemplateDeclaration::deduceFunctionTemplate(Scope *sc, Loc loc,
     printf("    targsi:\n");
     if (targsi)
     {   for (int i = 0; i < targsi->dim; i++)
-        {   Object *arg = (Object *)targsi->data[i];
+        {   Object *arg = targsi->tdata()[i];
             printf("\t%s\n", arg->toChars());
         }
     }
     printf("    fargs:\n");
     for (int i = 0; i < fargs->dim; i++)
-    {   Expression *arg = (Expression *)fargs->data[i];
+    {   Expression *arg = fargs->tdata()[i];
         printf("\t%s %s\n", arg->type->toChars(), arg->toChars());
         //printf("\tty = %d\n", arg->type->ty);
     }
@@ -1587,7 +1587,7 @@ FuncDeclaration *TemplateDeclaration::deduceFunctionTemplate(Scope *sc, Loc loc,
         td_best = td;
         m_best = m;
         tdargs->setDim(dedargs.dim);
-        memcpy(tdargs->data, dedargs.data, tdargs->dim * sizeof(void *));
+        memcpy(tdargs->tdata(), dedargs.tdata(), tdargs->dim * sizeof(void *));
         continue;
     }
     if (!td_best)
@@ -1629,7 +1629,7 @@ FuncDeclaration *TemplateDeclaration::deduceFunctionTemplate(Scope *sc, Loc loc,
             {
                 if (i)
                     bufa.writeByte(',');
-                Object *oarg = (Object *)args->data[i];
+                Object *oarg = args->tdata()[i];
                 ObjectToCBuffer(&bufa, &hgs, oarg);
             }
         }
@@ -1654,9 +1654,9 @@ void TemplateDeclaration::toCBuffer(OutBuffer *buf, HdrGenState *hgs)
     buf->writeByte('(');
     for (int i = 0; i < parameters->dim; i++)
     {
-        TemplateParameter *tp = (TemplateParameter *)parameters->data[i];
+        TemplateParameter *tp = parameters->tdata()[i];
         if (hgs->ddoc)
-            tp = (TemplateParameter *)origParameters->data[i];
+            tp = origParameters->tdata()[i];
         if (i)
             buf->writeByte(',');
         tp->toCBuffer(buf, hgs);
@@ -1678,7 +1678,7 @@ void TemplateDeclaration::toCBuffer(OutBuffer *buf, HdrGenState *hgs)
         buf->writenl();
         for (int i = 0; i < members->dim; i++)
         {
-            Dsymbol *s = (Dsymbol *)members->data[i];
+            Dsymbol *s = members->tdata()[i];
             s->toCBuffer(buf, hgs);
         }
         buf->writebyte('}');
@@ -1697,7 +1697,7 @@ char *TemplateDeclaration::toChars()
     buf.writeByte('(');
     for (int i = 0; i < parameters->dim; i++)
     {
-        TemplateParameter *tp = (TemplateParameter *)parameters->data[i];
+        TemplateParameter *tp = parameters->tdata()[i];
         if (i)
             buf.writeByte(',');
         tp->toCBuffer(&buf, &hgs);
@@ -1724,7 +1724,7 @@ char *TemplateDeclaration::toChars()
 int templateIdentifierLookup(Identifier *id, TemplateParameters *parameters)
 {
     for (size_t i = 0; i < parameters->dim; i++)
-    {   TemplateParameter *tp = (TemplateParameter *)parameters->data[i];
+    {   TemplateParameter *tp = parameters->tdata()[i];
 
         if (tp->ident->equals(id))
             return i;
@@ -1787,7 +1787,7 @@ MATCH Type::deduceType(Scope *sc, Type *tparam, TemplateParameters *parameters,
             Loc loc;
             if (parameters->dim)
             {
-                TemplateParameter *tp = (TemplateParameter *)parameters->data[0];
+                TemplateParameter *tp = parameters->tdata()[0];
                 loc = tp->loc;
             }
 
@@ -1799,13 +1799,13 @@ MATCH Type::deduceType(Scope *sc, Type *tparam, TemplateParameters *parameters,
             return deduceType(sc, tparam, parameters, dedtypes);
         }
 
-        TemplateParameter *tp = (TemplateParameter *)parameters->data[i];
+        TemplateParameter *tp = parameters->tdata()[i];
 
         // Found the corresponding parameter tp
         if (!tp->isTemplateTypeParameter())
             goto Lnomatch;
         Type *tt = this;
-        Type *at = (Type *)dedtypes->data[i];
+        Type *at = (Type *)dedtypes->tdata()[i];
 
         // 7*7 == 49 cases
 
@@ -1827,7 +1827,7 @@ MATCH Type::deduceType(Scope *sc, Type *tparam, TemplateParameters *parameters,
                 // foo(U:U) wild(T)                        => wild(T)
                 // foo(U:U) wild(shared(T))                => wild(shared(T))
                 if (!at)
-                {   dedtypes->data[i] = (void *)tt;
+                {   dedtypes->tdata()[i] = tt;
                     goto Lexact;
                 }
                 break;
@@ -1846,7 +1846,7 @@ MATCH Type::deduceType(Scope *sc, Type *tparam, TemplateParameters *parameters,
                 // foo(U:wild(shared(U))  wild(shared(T)) => T
                 tt = mutableOf()->unSharedOf();
                 if (!at)
-                {   dedtypes->data[i] = (void *)tt;
+                {   dedtypes->tdata()[i] = tt;
                     goto Lexact;
                 }
                 break;
@@ -1864,7 +1864,7 @@ MATCH Type::deduceType(Scope *sc, Type *tparam, TemplateParameters *parameters,
                 // foo(U:const(U)) wild(shared(T))         => shared(T)
                 tt = mutableOf();
                 if (!at)
-                {   dedtypes->data[i] = (void *)tt;
+                {   dedtypes->tdata()[i] = tt;
                     goto Lconst;
                 }
                 break;
@@ -1877,7 +1877,7 @@ MATCH Type::deduceType(Scope *sc, Type *tparam, TemplateParameters *parameters,
                 // foo(U:shared(U)) wild(shared(T))        => wild(T)
                 tt = unSharedOf();
                 if (!at)
-                {   dedtypes->data[i] = (void *)tt;
+                {   dedtypes->tdata()[i] = tt;
                     goto Lconst;
                 }
                 break;
@@ -2024,11 +2024,11 @@ MATCH TypeSArray::deduceType(Scope *sc, Type *tparam, TemplateParameters *parame
                 // This code matches code in TypeInstance::deduceType()
                 if (i == -1)
                     goto Lnomatch;
-                TemplateParameter *tp = (TemplateParameter *)parameters->data[i];
+                TemplateParameter *tp = parameters->tdata()[i];
                 TemplateValueParameter *tvp = tp->isTemplateValueParameter();
                 if (!tvp)
                     goto Lnomatch;
-                Expression *e = (Expression *)dedtypes->data[i];
+                Expression *e = (Expression *)dedtypes->tdata()[i];
                 if (e)
                 {
                     if (!dim->equals(e))
@@ -2039,7 +2039,7 @@ MATCH TypeSArray::deduceType(Scope *sc, Type *tparam, TemplateParameters *parame
                     MATCH m = (MATCH)dim->implicitConvTo(vt);
                     if (!m)
                         goto Lnomatch;
-                    dedtypes->data[i] = dim;
+                    dedtypes->tdata()[i] = dim;
                 }
             }
             else if (dim->toInteger() != tp->dim->toInteger())
@@ -2056,7 +2056,7 @@ MATCH TypeSArray::deduceType(Scope *sc, Type *tparam, TemplateParameters *parame
 
                     for (size_t i = 0; i < parameters->dim; i++)
                     {
-                        TemplateParameter *tp = (TemplateParameter *)parameters->data[i];
+                        TemplateParameter *tp = parameters->tdata()[i];
 
                         if (tp->ident->equals(id))
                         {   // Found the corresponding template parameter
@@ -2064,13 +2064,13 @@ MATCH TypeSArray::deduceType(Scope *sc, Type *tparam, TemplateParameters *parame
                             if (!tvp || !tvp->valType->isintegral())
                                 goto Lnomatch;
 
-                            if (dedtypes->data[i])
+                            if (dedtypes->tdata()[i])
                             {
-                                if (!dim->equals((Object *)dedtypes->data[i]))
+                                if (!dim->equals(dedtypes->tdata()[i]))
                                     goto Lnomatch;
                             }
                             else
-                            {   dedtypes->data[i] = (void *)dim;
+                            {   dedtypes->tdata()[i] = dim;
                             }
                             return next->deduceType(sc, tparam->nextOf(), parameters, dedtypes);
                         }
@@ -2152,7 +2152,7 @@ MATCH TypeFunction::deduceType(Scope *sc, Type *tparam, TemplateParameters *para
             for (; 1; tupi++)
             {   if (tupi == parameters->dim)
                     goto L1;
-                TemplateParameter *t = (TemplateParameter *)parameters->data[tupi];
+                TemplateParameter *t = parameters->tdata()[tupi];
                 TemplateTupleParameter *tup = t->isTemplateTupleParameter();
                 if (tup && tup->ident->equals(tid->ident))
                     break;
@@ -2165,7 +2165,7 @@ MATCH TypeFunction::deduceType(Scope *sc, Type *tparam, TemplateParameters *para
 
             /* See if existing tuple, and whether it matches or not
              */
-            Object *o = (Object *)dedtypes->data[tupi];
+            Object *o = dedtypes->tdata()[tupi];
             if (o)
             {   // Existing deduced argument must be a tuple, and must match
                 Tuple *t = isTuple(o);
@@ -2173,7 +2173,7 @@ MATCH TypeFunction::deduceType(Scope *sc, Type *tparam, TemplateParameters *para
                     return MATCHnomatch;
                 for (size_t i = 0; i < tuple_dim; i++)
                 {   Parameter *arg = Parameter::getNth(this->parameters, nfparams - 1 + i);
-                    if (!arg->type->equals((Object *)t->objects.data[i]))
+                    if (!arg->type->equals(t->objects.tdata()[i]))
                         return MATCHnomatch;
                 }
             }
@@ -2183,9 +2183,9 @@ MATCH TypeFunction::deduceType(Scope *sc, Type *tparam, TemplateParameters *para
                 t->objects.setDim(tuple_dim);
                 for (size_t i = 0; i < tuple_dim; i++)
                 {   Parameter *arg = Parameter::getNth(this->parameters, nfparams - 1 + i);
-                    t->objects.data[i] = (void *)arg->type;
+                    t->objects.tdata()[i] = arg->type;
                 }
-                dedtypes->data[tupi] = (void *)t;
+                dedtypes->tdata()[tupi] = t;
             }
             nfparams--; // don't consider the last parameter for type deduction
             goto L2;
@@ -2216,8 +2216,8 @@ MATCH TypeIdentifier::deduceType(Scope *sc, Type *tparam, TemplateParameters *pa
 
         for (int i = 0; i < idents.dim; i++)
         {
-            Identifier *id1 = (Identifier *)idents.data[i];
-            Identifier *id2 = (Identifier *)tp->idents.data[i];
+            Identifier *id1 = idents.tdata()[i];
+            Identifier *id2 = tp->idents.tdata()[i];
 
             if (!id1->equals(id2))
                 return MATCHnomatch;
@@ -2265,7 +2265,7 @@ MATCH TypeInstance::deduceType(Scope *sc,
                     }
                     goto Lnomatch;
                 }
-                TemplateParameter *tpx = (TemplateParameter *)parameters->data[i];
+                TemplateParameter *tpx = parameters->tdata()[i];
                 // This logic duplicates tpx->matchArg()
                 TemplateAliasParameter *ta = tpx->isTemplateAliasParameter();
                 if (!ta)
@@ -2275,14 +2275,14 @@ MATCH TypeInstance::deduceType(Scope *sc,
                     goto Lnomatch;
                 if (ta->specAlias && sa != ta->specAlias)
                     goto Lnomatch;
-                if (dedtypes->data[i])
+                if (dedtypes->tdata()[i])
                 {   // Must match already deduced symbol
-                    Object *s = (Object *)dedtypes->data[i];
+                    Object *s = dedtypes->tdata()[i];
 
                     if (s != sa)
                         goto Lnomatch;
                 }
-                dedtypes->data[i] = sa;
+                dedtypes->tdata()[i] = sa;
             }
         }
         else if (tempinst->tempdecl != tp->tempinst->tempdecl)
@@ -2295,17 +2295,17 @@ MATCH TypeInstance::deduceType(Scope *sc,
             //printf("\ttest: tempinst->tiargs[%d]\n", i);
             Object *o1;
             if (i < tempinst->tiargs->dim)
-                o1 = (Object *)tempinst->tiargs->data[i];
+                o1 = tempinst->tiargs->tdata()[i];
             else if (i < tempinst->tdtypes.dim && i < tp->tempinst->tiargs->dim)
                 // Pick up default arg
-                o1 = (Object *)tempinst->tdtypes.data[i];
+                o1 = tempinst->tdtypes.tdata()[i];
             else
                 break;
 
             if (i >= tp->tempinst->tiargs->dim)
                 goto Lnomatch;
 
-            Object *o2 = (Object *)tp->tempinst->tiargs->data[i];
+            Object *o2 = tp->tempinst->tiargs->tdata()[i];
 
             Type *t1 = isType(o1);
             Type *t2 = isType(o2);
@@ -2354,16 +2354,16 @@ MATCH TypeInstance::deduceType(Scope *sc,
                 int vtdim = tempinst->tiargs->dim - i;
                 vt->objects.setDim(vtdim);
                 for (size_t k = 0; k < vtdim; k++)
-                    vt->objects.data[k] = (void *)tempinst->tiargs->data[i + k];
+                    vt->objects.tdata()[k] = tempinst->tiargs->tdata()[i + k];
 
-                Tuple *v = (Tuple *)dedtypes->data[j];
+                Tuple *v = (Tuple *)dedtypes->tdata()[j];
                 if (v)
                 {
                     if (!match(v, vt, tempinst->tempdecl, sc))
                         goto Lnomatch;
                 }
                 else
-                    dedtypes->data[j] = vt;
+                    dedtypes->tdata()[j] = vt;
                 break; //return MATCHexact;
             }
 
@@ -2392,12 +2392,12 @@ MATCH TypeInstance::deduceType(Scope *sc,
             L1:
                 if (j == -1)
                     goto Lnomatch;
-                TemplateParameter *tp = (TemplateParameter *)parameters->data[j];
+                TemplateParameter *tp = parameters->tdata()[j];
                 // BUG: use tp->matchArg() instead of the following
                 TemplateValueParameter *tv = tp->isTemplateValueParameter();
                 if (!tv)
                     goto Lnomatch;
-                Expression *e = (Expression *)dedtypes->data[j];
+                Expression *e = (Expression *)dedtypes->tdata()[j];
                 if (e)
                 {
                     if (!e1->equals(e))
@@ -2408,7 +2408,7 @@ MATCH TypeInstance::deduceType(Scope *sc,
                     MATCH m = (MATCH)e1->implicitConvTo(vt);
                     if (!m)
                         goto Lnomatch;
-                    dedtypes->data[j] = e1;
+                    dedtypes->tdata()[j] = e1;
                 }
             }
             else if (s1 && t2 && t2->ty == Tident)
@@ -2416,12 +2416,12 @@ MATCH TypeInstance::deduceType(Scope *sc,
                 j = templateParameterLookup(t2, parameters);
                 if (j == -1)
                     goto Lnomatch;
-                TemplateParameter *tp = (TemplateParameter *)parameters->data[j];
+                TemplateParameter *tp = parameters->tdata()[j];
                 // BUG: use tp->matchArg() instead of the following
                 TemplateAliasParameter *ta = tp->isTemplateAliasParameter();
                 if (!ta)
                     goto Lnomatch;
-                Dsymbol *s = (Dsymbol *)dedtypes->data[j];
+                Dsymbol *s = (Dsymbol *)dedtypes->tdata()[j];
                 if (s)
                 {
                     if (!s1->equals(s))
@@ -2429,7 +2429,7 @@ MATCH TypeInstance::deduceType(Scope *sc,
                 }
                 else
                 {
-                    dedtypes->data[j] = s1;
+                    dedtypes->tdata()[j] = s1;
                 }
             }
             else if (s1 && s2)
@@ -2474,7 +2474,7 @@ MATCH TypeStruct::deduceType(Scope *sc, Type *tparam, TemplateParameters *parame
          */
         TypeInstance *tpi = (TypeInstance *)tparam;
         if (tpi->idents.dim)
-        {   Identifier *id = (Identifier *)tpi->idents.data[tpi->idents.dim - 1];
+        {   Identifier *id = tpi->idents.tdata()[tpi->idents.dim - 1];
             if (id->dyncast() == DYNCAST_IDENTIFIER && sym->ident->equals(id))
             {
                 Type *tparent = sym->parent->getType();
@@ -2556,7 +2556,7 @@ void deduceBaseClassParameters(BaseClass *b,
         // Make a temporary copy of dedtypes so we don't destroy it
         Objects *tmpdedtypes = new Objects();
         tmpdedtypes->setDim(dedtypes->dim);
-        memcpy(tmpdedtypes->data, dedtypes->data, dedtypes->dim * sizeof(void *));
+        memcpy(tmpdedtypes->tdata(), dedtypes->tdata(), dedtypes->dim * sizeof(void *));
 
         TypeInstance *t = new TypeInstance(0, parti);
         MATCH m = t->deduceType(sc, tparam, parameters, tmpdedtypes);
@@ -2564,13 +2564,13 @@ void deduceBaseClassParameters(BaseClass *b,
         {
             // If this is the first ever match, it becomes our best estimate
             if (numBaseClassMatches==0)
-                memcpy(best->data, tmpdedtypes->data, tmpdedtypes->dim * sizeof(void *));
+                memcpy(best->tdata(), tmpdedtypes->tdata(), tmpdedtypes->dim * sizeof(void *));
             else for (size_t k = 0; k < tmpdedtypes->dim; ++k)
             {
                 // If we've found more than one possible type for a parameter,
                 // mark it as unknown.
-                if (tmpdedtypes->data[k] != best->data[k])
-                    best->data[k] = dedtypes->data[k];
+                if (tmpdedtypes->tdata()[k] != best->tdata()[k])
+                    best->tdata()[k] = dedtypes->tdata()[k];
             }
             ++numBaseClassMatches;
         }
@@ -2612,7 +2612,7 @@ MATCH TypeClass::deduceType(Scope *sc, Type *tparam, TemplateParameters *paramet
          */
         TypeInstance *tpi = (TypeInstance *)tparam;
         if (tpi->idents.dim)
-        {   Identifier *id = (Identifier *)tpi->idents.data[tpi->idents.dim - 1];
+        {   Identifier *id = tpi->idents.tdata()[tpi->idents.dim - 1];
             if (id->dyncast() == DYNCAST_IDENTIFIER && sym->ident->equals(id))
             {
                 Type *tparent = sym->parent->getType();
@@ -2648,7 +2648,7 @@ MATCH TypeClass::deduceType(Scope *sc, Type *tparam, TemplateParameters *paramet
         while(s && s->baseclasses->dim > 0)
         {
             // Test the base class
-            deduceBaseClassParameters((BaseClass *)(s->baseclasses->data[0]),
+            deduceBaseClassParameters((s->baseclasses->tdata()[0]),
                 sc, tparam, parameters, dedtypes,
                 best, numBaseClassMatches);
 
@@ -2659,14 +2659,14 @@ MATCH TypeClass::deduceType(Scope *sc, Type *tparam, TemplateParameters *paramet
                 deduceBaseClassParameters(b, sc, tparam, parameters, dedtypes,
                     best, numBaseClassMatches);
             }
-            s = ((BaseClass *)(s->baseclasses->data[0]))->base;
+            s = ((s->baseclasses->tdata()[0]))->base;
         }
 
         if (numBaseClassMatches == 0)
             return MATCHnomatch;
 
         // If we got at least one match, copy the known types into dedtypes
-        memcpy(dedtypes->data, best->data, best->dim * sizeof(void *));
+        memcpy(dedtypes->tdata(), best->tdata(), best->dim * sizeof(void *));
         return MATCHconvert;
     }
 
@@ -2818,14 +2818,14 @@ MATCH TemplateTypeParameter::matchArg(Scope *sc, Objects *tiargs,
     Type *ta;
 
     if (i < tiargs->dim)
-        oarg = (Object *)tiargs->data[i];
+        oarg = tiargs->tdata()[i];
     else
     {   // Get default argument instead
         oarg = defaultArg(loc, sc);
         if (!oarg)
         {   assert(i < dedtypes->dim);
             // It might have already been deduced
-            oarg = (Object *)dedtypes->data[i];
+            oarg = dedtypes->tdata()[i];
             if (!oarg)
             {
                 goto Lnomatch;
@@ -2842,7 +2842,7 @@ MATCH TemplateTypeParameter::matchArg(Scope *sc, Objects *tiargs,
     }
     //printf("ta is %s\n", ta->toChars());
 
-    t = (Type *)dedtypes->data[i];
+    t = (Type *)dedtypes->tdata()[i];
 
     if (specType)
     {
@@ -2855,7 +2855,7 @@ MATCH TemplateTypeParameter::matchArg(Scope *sc, Objects *tiargs,
 
         if (m2 < m)
             m = m2;
-        t = (Type *)dedtypes->data[i];
+        t = (Type *)dedtypes->tdata()[i];
     }
     else
     {
@@ -2881,7 +2881,7 @@ MATCH TemplateTypeParameter::matchArg(Scope *sc, Objects *tiargs,
 
     if (!t)
     {
-        dedtypes->data[i] = ta;
+        dedtypes->tdata()[i] = ta;
         t = ta;
     }
     *psparam = new AliasDeclaration(loc, ident, t);
@@ -3098,14 +3098,14 @@ MATCH TemplateAliasParameter::matchArg(Scope *sc,
     //printf("TemplateAliasParameter::matchArg()\n");
 
     if (i < tiargs->dim)
-        oarg = (Object *)tiargs->data[i];
+        oarg = tiargs->tdata()[i];
     else
     {   // Get default argument instead
         oarg = defaultArg(loc, sc);
         if (!oarg)
         {   assert(i < dedtypes->dim);
             // It might have already been deduced
-            oarg = (Object *)dedtypes->data[i];
+            oarg = dedtypes->tdata()[i];
             if (!oarg)
                 goto Lnomatch;
         }
@@ -3147,14 +3147,14 @@ MATCH TemplateAliasParameter::matchArg(Scope *sc,
         if (sa != specAlias)
             goto Lnomatch;
     }
-    else if (dedtypes->data[i])
+    else if (dedtypes->tdata()[i])
     {   // Must match already deduced symbol
-        Object *s = (Object *)dedtypes->data[i];
+        Object *s = dedtypes->tdata()[i];
 
         if (!sa || s != sa)
             goto Lnomatch;
     }
-    dedtypes->data[i] = sa;
+    dedtypes->tdata()[i] = sa;
 
     s = isDsymbol(sa);
     if (s)
@@ -3363,14 +3363,14 @@ MATCH TemplateValueParameter::matchArg(Scope *sc,
     Object *oarg;
 
     if (i < tiargs->dim)
-        oarg = (Object *)tiargs->data[i];
+        oarg = tiargs->tdata()[i];
     else
     {   // Get default argument instead
         oarg = defaultArg(loc, sc);
         if (!oarg)
         {   assert(i < dedtypes->dim);
             // It might have already been deduced
-            oarg = (Object *)dedtypes->data[i];
+            oarg = dedtypes->tdata()[i];
             if (!oarg)
                 goto Lnomatch;
         }
@@ -3408,9 +3408,9 @@ MATCH TemplateValueParameter::matchArg(Scope *sc,
         if (!ei->equals(e))
             goto Lnomatch;
     }
-    else if (dedtypes->data[i])
+    else if (dedtypes->tdata()[i])
     {   // Must match already deduced value
-        Expression *e = (Expression *)dedtypes->data[i];
+        Expression *e = (Expression *)dedtypes->tdata()[i];
 
         if (!ei || !ei->equals(e))
             goto Lnomatch;
@@ -3427,7 +3427,7 @@ MATCH TemplateValueParameter::matchArg(Scope *sc,
         if (!m)
             goto Lnomatch;
     }
-    dedtypes->data[i] = ei;
+    dedtypes->tdata()[i] = ei;
 
     init = new ExpInitializer(loc, ei);
     sparam = new VarDeclaration(loc, vt, ident, init);
@@ -3564,11 +3564,11 @@ MATCH TemplateTupleParameter::matchArg(Scope *sc,
     assert(i + 1 == dedtypes->dim);     // must be the last one
     Tuple *ovar;
 
-    if (dedtypes->data[i] && isTuple((Object *)dedtypes->data[i]))
+    if (dedtypes->tdata()[i] && isTuple(dedtypes->tdata()[i]))
         // It was already been deduced
-        ovar = isTuple((Object *)dedtypes->data[i]);
-    else if (i + 1 == tiargs->dim && isTuple((Object *)tiargs->data[i]))
-        ovar = isTuple((Object *)tiargs->data[i]);
+        ovar = isTuple(dedtypes->tdata()[i]);
+    else if (i + 1 == tiargs->dim && isTuple(tiargs->tdata()[i]))
+        ovar = isTuple(tiargs->tdata()[i]);
     else
     {
         ovar = new Tuple();
@@ -3578,11 +3578,11 @@ MATCH TemplateTupleParameter::matchArg(Scope *sc,
             //printf("i = %d, tiargs->dim = %d\n", i, tiargs->dim);
             ovar->objects.setDim(tiargs->dim - i);
             for (size_t j = 0; j < ovar->objects.dim; j++)
-                ovar->objects.data[j] = tiargs->data[i + j];
+                ovar->objects.tdata()[j] = tiargs->tdata()[i + j];
         }
     }
     *psparam = new TupleDeclaration(loc, ident, &ovar->objects);
-    dedtypes->data[i] = (void *)ovar;
+    dedtypes->tdata()[i] = ovar;
     return MATCHexact;
 }
 
@@ -3599,7 +3599,7 @@ void TemplateTupleParameter::print(Object *oarg, Object *oded)
         if (i)
             printf(", ");
 
-        Object *o = (Object *)v->objects.data[i];
+        Object *o = v->objects.tdata()[i];
 
         Dsymbol *sa = isDsymbol(o);
         if (sa)
@@ -3707,7 +3707,7 @@ Objects *TemplateInstance::arraySyntaxCopy(Objects *objs)
         a->setDim(objs->dim);
         for (size_t i = 0; i < objs->dim; i++)
         {
-            a->data[i] = objectSyntaxCopy((Object *)objs->data[i]);
+            a->tdata()[i] = objectSyntaxCopy(objs->tdata()[i]);
         }
     }
     return a;
@@ -3823,7 +3823,7 @@ void TemplateInstance::semantic(Scope *sc, Expressions *fargs)
 
     for (size_t i = 0; i < tempdecl->instances.dim; i++)
     {
-        TemplateInstance *ti = (TemplateInstance *)tempdecl->instances.data[i];
+        TemplateInstance *ti = tempdecl->instances.tdata()[i];
 #if LOG
         printf("\t%s: checking for match with instance %d (%p): '%s'\n", toChars(), i, ti, ti->toChars());
 #endif
@@ -3854,7 +3854,7 @@ void TemplateInstance::semantic(Scope *sc, Expressions *fargs)
                 size_t nfparams = Parameter::dim(fparameters); // Num function parameters
                 for (int i = 0; i < nfparams && i < fargs->dim; i++)
                 {   Parameter *fparam = Parameter::getNth(fparameters, i);
-                    Expression *farg = (Expression *)fargs->data[i];
+                    Expression *farg = fargs->tdata()[i];
                     if (fparam->storageClass & STCauto)         // if "auto ref"
                     {
                         if (farg->isLvalue())
@@ -3949,7 +3949,7 @@ void TemplateInstance::semantic(Scope *sc, Expressions *fargs)
                 a->push(this);
                 break;
             }
-            if (this == (Dsymbol *)a->data[i])  // if already in Array
+            if (this == a->tdata()[i])  // if already in Array
                 break;
         }
     }
@@ -3986,7 +3986,7 @@ void TemplateInstance::semantic(Scope *sc, Expressions *fargs)
     int memnum = 0;
     for (int i = 0; i < members->dim; i++)
     {
-        Dsymbol *s = (Dsymbol *)members->data[i];
+        Dsymbol *s = members->tdata()[i];
 #if LOG
         printf("\t[%d] adding member '%s' %p kind %s to '%s', memnum = %d\n", i, s->toChars(), s, s->kind(), this->toChars(), memnum);
 #endif
@@ -4057,7 +4057,7 @@ void TemplateInstance::semantic(Scope *sc, Expressions *fargs)
     }
     for (int i = 0; i < members->dim; i++)
     {
-        Dsymbol *s = (Dsymbol *)members->data[i];
+        Dsymbol *s = members->tdata()[i];
         //printf("\t[%d] semantic on '%s' %p kind %s in '%s'\n", i, s->toChars(), s, s->kind(), this->toChars());
         //printf("test: isnested = %d, sc2->parent = %s\n", isnested, sc2->parent->toChars());
 //      if (isnested)
@@ -4083,7 +4083,7 @@ void TemplateInstance::semantic(Scope *sc, Expressions *fargs)
      * or semantic3() yet.
      */
     for (size_t i = 0; i < Module::deferred.dim; i++)
-    {   Dsymbol *sd = (Dsymbol *)Module::deferred.data[i];
+    {   Dsymbol *sd = Module::deferred.tdata()[i];
 
         if (sd->parent == this)
             goto Laftersemantic;
@@ -4180,12 +4180,12 @@ void TemplateInstance::semanticTiargs(Loc loc, Scope *sc, Objects *tiargs, int f
         return;
     for (size_t j = 0; j < tiargs->dim; j++)
     {
-        Object *o = (Object *)tiargs->data[j];
+        Object *o = tiargs->tdata()[j];
         Type *ta = isType(o);
         Expression *ea = isExpression(o);
         Dsymbol *sa = isDsymbol(o);
 
-        //printf("1: tiargs->data[%d] = %p, %p, %p, ea=%p, ta=%p\n", j, o, isDsymbol(o), isTuple(o), ea, ta);
+        //printf("1: tiargs->tdata()[%d] = %p, %p, %p, ea=%p, ta=%p\n", j, o, isDsymbol(o), isTuple(o), ea, ta);
         if (ta)
         {
             //printf("type %s\n", ta->toChars());
@@ -4203,10 +4203,10 @@ void TemplateInstance::semanticTiargs(Loc loc, Scope *sc, Objects *tiargs, int f
                     ea = ea->optimize(WANTvalue);
                 else if (ea->op != TOKvar)
                     ea = ea->optimize(WANTvalue | WANTinterpret);
-                tiargs->data[j] = ea;
+                tiargs->tdata()[j] = ea;
             }
             else if (sa)
-            {   tiargs->data[j] = sa;
+            {   tiargs->tdata()[j] = sa;
                 TupleDeclaration *d = sa->toAlias()->isTupleDeclaration();
                 if (d)
                 {
@@ -4227,19 +4227,19 @@ void TemplateInstance::semanticTiargs(Loc loc, Scope *sc, Objects *tiargs, int f
                     if (dim)
                     {   tiargs->reserve(dim);
                         for (size_t i = 0; i < dim; i++)
-                        {   Parameter *arg = (Parameter *)tt->arguments->data[i];
+                        {   Parameter *arg = tt->arguments->tdata()[i];
                             tiargs->insert(j + i, arg->type);
                         }
                     }
                     j--;
                 }
                 else
-                    tiargs->data[j] = ta;
+                    tiargs->tdata()[j] = ta;
             }
             else
             {
                 assert(global.errors);
-                tiargs->data[j] = Type::terror;
+                tiargs->tdata()[j] = Type::terror;
             }
         }
         else if (ea)
@@ -4254,7 +4254,7 @@ void TemplateInstance::semanticTiargs(Loc loc, Scope *sc, Objects *tiargs, int f
                 ea = ea->optimize(WANTvalue);
             else if (ea->op != TOKvar)
                 ea = ea->optimize(WANTvalue | WANTinterpret);
-            tiargs->data[j] = ea;
+            tiargs->tdata()[j] = ea;
             if (ea->op == TOKtype)
             {   ta = ea->type;
                 goto Ltype;
@@ -4282,13 +4282,13 @@ void TemplateInstance::semanticTiargs(Loc loc, Scope *sc, Objects *tiargs, int f
         {
             assert(0);
         }
-        //printf("1: tiargs->data[%d] = %p\n", j, tiargs->data[j]);
+        //printf("1: tiargs->tdata()[%d] = %p\n", j, tiargs->tdata()[j]);
     }
 #if 0
     printf("-TemplateInstance::semanticTiargs()\n");
     for (size_t j = 0; j < tiargs->dim; j++)
     {
-        Object *o = (Object *)tiargs->data[j];
+        Object *o = tiargs->tdata()[j];
         Type *ta = isType(o);
         Expression *ea = isExpression(o);
         Dsymbol *sa = isDsymbol(o);
@@ -4335,7 +4335,7 @@ TemplateDeclaration *TemplateInstance::findTemplateDeclaration(Scope *sc)
         if (os)
         {   s = NULL;
             for (int i = 0; i < os->a.dim; i++)
-            {   Dsymbol *s2 = (Dsymbol *)os->a.data[i];
+            {   Dsymbol *s2 = os->a.tdata()[i];
                 if (s2->isTemplateDeclaration())
                 {
                     if (s)
@@ -4459,7 +4459,7 @@ TemplateDeclaration *TemplateInstance::findBestMatch(Scope *sc)
     {
         MATCH m;
 
-//if (tiargs->dim) printf("2: tiargs->dim = %d, data[0] = %p\n", tiargs->dim, tiargs->data[0]);
+//if (tiargs->dim) printf("2: tiargs->dim = %d, data[0] = %p\n", tiargs->dim, tiargs->tdata()[0]);
 
         // If more arguments than parameters,
         // then this is no match.
@@ -4509,7 +4509,7 @@ TemplateDeclaration *TemplateInstance::findBestMatch(Scope *sc)
         td_best = td;
         m_best = m;
         tdtypes.setDim(dedtypes.dim);
-        memcpy(tdtypes.data, dedtypes.data, tdtypes.dim * sizeof(void *));
+        memcpy(tdtypes.tdata(), dedtypes.tdata(), tdtypes.dim * sizeof(void *));
         continue;
     }
 
@@ -4538,9 +4538,9 @@ TemplateDeclaration *TemplateInstance::findBestMatch(Scope *sc)
     /* Cast any value arguments to be same type as value parameter
      */
     for (size_t i = 0; i < tiargs->dim; i++)
-    {   Object *o = (Object *)tiargs->data[i];
+    {   Object *o = tiargs->tdata()[i];
         Expression *ea = isExpression(o);       // value argument
-        TemplateParameter *tp = (TemplateParameter *)tempdecl->parameters->data[i];
+        TemplateParameter *tp = tempdecl->parameters->tdata()[i];
         assert(tp);
         TemplateValueParameter *tvp = tp->isTemplateValueParameter();
         if (tvp)
@@ -4548,7 +4548,7 @@ TemplateDeclaration *TemplateInstance::findBestMatch(Scope *sc)
             assert(ea);
             ea = ea->castTo(tvp->valType);
             ea = ea->optimize(WANTvalue | WANTinterpret);
-            tiargs->data[i] = (Object *)ea;
+            tiargs->tdata()[i] = (Object *)ea;
         }
     }
 #endif
@@ -4573,7 +4573,7 @@ int TemplateInstance::hasNestedArgs(Objects *args)
      * symbol that is on the stack.
      */
     for (size_t i = 0; i < args->dim; i++)
-    {   Object *o = (Object *)args->data[i];
+    {   Object *o = args->tdata()[i];
         Expression *ea = isExpression(o);
         Dsymbol *sa = isDsymbol(o);
         Tuple *va = isTuple(o);
@@ -4658,7 +4658,7 @@ Identifier *TemplateInstance::genIdent(Objects *args)
     char *id = tempdecl->ident->toChars();
     buf.printf("__T%zu%s", strlen(id), id);
     for (int i = 0; i < args->dim; i++)
-    {   Object *o = (Object *)args->data[i];
+    {   Object *o = args->tdata()[i];
         Type *ta = isType(o);
         Expression *ea = isExpression(o);
         Dsymbol *sa = isDsymbol(o);
@@ -4709,7 +4709,7 @@ Identifier *TemplateInstance::genIdent(Objects *args)
             buf.writestring(ea->type->deco);
 #else
             // Use type of parameter, not type of argument
-            TemplateParameter *tp = (TemplateParameter *)tempdecl->parameters->data[i];
+            TemplateParameter *tp = tempdecl->parameters->tdata()[i];
             assert(tp);
             TemplateValueParameter *tvp = tp->isTemplateValueParameter();
             assert(tvp);
@@ -4775,9 +4775,9 @@ void TemplateInstance::declareParameters(Scope *sc)
     //printf("TemplateInstance::declareParameters()\n");
     for (int i = 0; i < tdtypes.dim; i++)
     {
-        TemplateParameter *tp = (TemplateParameter *)tempdecl->parameters->data[i];
-        //Object *o = (Object *)tiargs->data[i];
-        Object *o = (Object *)tdtypes.data[i];          // initializer for tp
+        TemplateParameter *tp = tempdecl->parameters->tdata()[i];
+        //Object *o = tiargs->tdata()[i];
+        Object *o = tdtypes.tdata()[i];          // initializer for tp
 
         //printf("\ttdtypes[%d] = %p\n", i, o);
         tempdecl->declareParameter(sc, tp, o);
@@ -4849,7 +4849,7 @@ void TemplateInstance::semantic2(Scope *sc)
         sc->tinst = this;
         for (i = 0; i < members->dim; i++)
         {
-            Dsymbol *s = (Dsymbol *)members->data[i];
+            Dsymbol *s = members->tdata()[i];
 #if LOG
 printf("\tmember '%s', kind = '%s'\n", s->toChars(), s->kind());
 #endif
@@ -4880,7 +4880,7 @@ void TemplateInstance::semantic3(Scope *sc)
         sc->tinst = this;
         for (int i = 0; i < members->dim; i++)
         {
-            Dsymbol *s = (Dsymbol *)members->data[i];
+            Dsymbol *s = members->tdata()[i];
             s->semantic3(sc);
         }
         sc = sc->pop();
@@ -4979,7 +4979,7 @@ void TemplateInstance::toObjFile(int multiobj)
         {
             for (int i = 0; i < members->dim; i++)
             {
-                Dsymbol *s = (Dsymbol *)members->data[i];
+                Dsymbol *s = members->tdata()[i];
                 s->toObjFile(multiobj);
             }
         }
@@ -4995,7 +4995,7 @@ void TemplateInstance::inlineScan()
     {
         for (int i = 0; i < members->dim; i++)
         {
-            Dsymbol *s = (Dsymbol *)members->data[i];
+            Dsymbol *s = members->tdata()[i];
             s->inlineScan();
         }
     }
@@ -5018,7 +5018,7 @@ void TemplateInstance::toCBuffer(OutBuffer *buf, HdrGenState *hgs)
         {
             if (i)
                 buf->writeByte(',');
-            Object *oarg = (Object *)args->data[i];
+            Object *oarg = args->tdata()[i];
             ObjectToCBuffer(buf, hgs, oarg);
         }
         nest--;
@@ -5081,7 +5081,7 @@ char *TemplateInstance::toChars()
 
 TemplateMixin::TemplateMixin(Loc loc, Identifier *ident, Type *tqual,
         Identifiers *idents, Objects *tiargs)
-        : TemplateInstance(loc, (Identifier *)idents->data[idents->dim - 1])
+        : TemplateInstance(loc, idents->tdata()[idents->dim - 1])
 {
     //printf("TemplateMixin(ident = '%s')\n", ident ? ident->toChars() : "");
     this->ident = ident;
@@ -5097,7 +5097,7 @@ Dsymbol *TemplateMixin::syntaxCopy(Dsymbol *s)
     ids->setDim(idents->dim);
     for (int i = 0; i < idents->dim; i++)
     {   // Matches TypeQualified::syntaxCopyHelper()
-        Identifier *id = (Identifier *)idents->data[i];
+        Identifier *id = idents->tdata()[i];
         if (id->dyncast() == DYNCAST_DSYMBOL)
         {
             TemplateInstance *ti = (TemplateInstance *)id;
@@ -5105,7 +5105,7 @@ Dsymbol *TemplateMixin::syntaxCopy(Dsymbol *s)
             ti = (TemplateInstance *)ti->syntaxCopy(NULL);
             id = (Identifier *)ti;
         }
-        ids->data[i] = id;
+        ids->tdata()[i] = id;
     }
 
     tm = new TemplateMixin(loc, ident,
@@ -5162,7 +5162,7 @@ void TemplateMixin::semantic(Scope *sc)
         else
         {
             i = 1;
-            id = (Identifier *)idents->data[0];
+            id = idents->tdata()[0];
             switch (id->dyncast())
             {
                 case DYNCAST_IDENTIFIER:
@@ -5185,7 +5185,7 @@ void TemplateMixin::semantic(Scope *sc)
         {
             if (!s)
                 break;
-            id = (Identifier *)idents->data[i];
+            id = idents->tdata()[i];
             s = s->searchX(loc, sc, id);
         }
         if (!s)
@@ -5263,11 +5263,11 @@ void TemplateMixin::semantic(Scope *sc)
             continue;
 
         for (int i = 0; i < tiargs->dim; i++)
-        {   Object *o = (Object *)tiargs->data[i];
+        {   Object *o = tiargs->tdata()[i];
             Type *ta = isType(o);
             Expression *ea = isExpression(o);
             Dsymbol *sa = isDsymbol(o);
-            Object *tmo = (Object *)tm->tiargs->data[i];
+            Object *tmo = tm->tiargs->tdata()[i];
             if (ta)
             {
                 Type *tmta = isType(tmo);
@@ -5334,7 +5334,7 @@ void TemplateMixin::semantic(Scope *sc)
     for (unsigned i = 0; i < members->dim; i++)
     {   Dsymbol *s;
 
-        s = (Dsymbol *)members->data[i];
+        s = members->tdata()[i];
         s->addMember(argscope, this, i);
         //sc->insert(s);
         //printf("sc->parent = %p, sc->scopesym = %p\n", sc->parent, sc->scopesym);
@@ -5360,7 +5360,7 @@ void TemplateMixin::semantic(Scope *sc)
 
     for (int i = 0; i < members->dim; i++)
     {
-        Dsymbol *s = (Dsymbol *)members->data[i];
+        Dsymbol *s = members->tdata()[i];
         s->semantic(sc2);
     }
 
@@ -5416,7 +5416,7 @@ void TemplateMixin::semantic2(Scope *sc)
         sc = sc->push(this);
         for (i = 0; i < members->dim; i++)
         {
-            Dsymbol *s = (Dsymbol *)members->data[i];
+            Dsymbol *s = members->tdata()[i];
 #if LOG
             printf("\tmember '%s', kind = '%s'\n", s->toChars(), s->kind());
 #endif
@@ -5445,7 +5445,7 @@ void TemplateMixin::semantic3(Scope *sc)
         sc = sc->push(this);
         for (i = 0; i < members->dim; i++)
         {
-            Dsymbol *s = (Dsymbol *)members->data[i];
+            Dsymbol *s = members->tdata()[i];
             s->semantic3(sc);
         }
         sc = sc->pop();
@@ -5473,7 +5473,7 @@ int TemplateMixin::hasPointers()
     //printf("TemplateMixin::hasPointers() %s\n", toChars());
     for (size_t i = 0; i < members->dim; i++)
     {
-        Dsymbol *s = (Dsymbol *)members->data[i];
+        Dsymbol *s = members->tdata()[i];
         //printf(" s = %s %s\n", s->kind(), s->toChars());
         if (s->hasPointers())
         {
@@ -5500,7 +5500,7 @@ void TemplateMixin::toCBuffer(OutBuffer *buf, HdrGenState *hgs)
     buf->writestring("mixin ");
 
     for (int i = 0; i < idents->dim; i++)
-    {   Identifier *id = (Identifier *)idents->data[i];
+    {   Identifier *id = idents->tdata()[i];
 
         if (i)
             buf->writeByte('.');
@@ -5512,7 +5512,7 @@ void TemplateMixin::toCBuffer(OutBuffer *buf, HdrGenState *hgs)
         for (int i = 0; i < tiargs->dim; i++)
         {   if (i)
                 buf->writebyte(',');
-            Object *oarg = (Object *)tiargs->data[i];
+            Object *oarg = tiargs->tdata()[i];
             Type *t = isType(oarg);
             Expression *e = isExpression(oarg);
             Dsymbol *s = isDsymbol(oarg);
diff --git a/src/tk/mem.c b/src/tk/mem.c
index 89f8e82007b6..462b2aacc55f 100644
--- a/src/tk/mem.c
+++ b/src/tk/mem.c
@@ -342,7 +342,7 @@ static struct mem_debug
 #define mem_ptrtodl(p)  ((struct mem_debug *) ((char *)p - offsetof(struct mem_debug,data[0])))
 
 /* Convert from a mem_debug struct to a mem_ptr.        */
-#define mem_dltoptr(dl) ((void *) &((dl)->data[0]))
+#define mem_dltoptr(dl) ( &((dl)->tdata()[0]))
 
 /*****************************
  * Set new value of file,line
@@ -439,9 +439,9 @@ void *mem_calloc_debug(unsigned n, const char *fil, int lin)
     dl->Mnbytes = n;
     dl->Mbeforeval = BEFOREVAL;
 #if SUN || SUN386 /* bus error if we store a long at an odd address */
-    memcpy(&(dl->data[n]),&afterval,sizeof(AFTERVAL));
+    memcpy(&(dl->tdata()[n]),&afterval,sizeof(AFTERVAL));
 #else
-    *(long *) &(dl->data[n]) = AFTERVAL;
+    * &(dl->tdata()[n]) = AFTERVAL;
 #endif
 
     /* Add dl to start of allocation list       */
@@ -476,9 +476,9 @@ void mem_free_debug(void *ptr, const char *fil, int lin)
                 goto err2;
         }
 #if SUN || SUN386 /* Bus error if we read a long from an odd address    */
-        if (memcmp(&dl->data[dl->Mnbytes],&afterval,sizeof(AFTERVAL)) != 0)
+        if (memcmp(&dl->tdata()[dl->Mnbytes],&afterval,sizeof(AFTERVAL)) != 0)
 #else
-        if (*(long *) &dl->data[dl->Mnbytes] != AFTERVAL)
+        if (* &dl->tdata()[dl->Mnbytes] != AFTERVAL)
 #endif
         {
                 PRINT "Pointer x%lx overrun\n",(long)ptr);
@@ -563,9 +563,9 @@ static void mem_checkdl(struct mem_debug *dl)
             goto err2;
     }
 #if SUN || SUN386 /* Bus error if we read a long from an odd address    */
-    if (memcmp(&dl->data[dl->Mnbytes],&afterval,sizeof(AFTERVAL)) != 0)
+    if (memcmp(&dl->tdata()[dl->Mnbytes],&afterval,sizeof(AFTERVAL)) != 0)
 #else
-    if (*(long *) &dl->data[dl->Mnbytes] != AFTERVAL)
+    if (* &dl->tdata()[dl->Mnbytes] != AFTERVAL)
 #endif
     {
             PRINT "Pointer x%lx overrun\n",(long)p);
@@ -600,7 +600,7 @@ void mem_checkptr(void *p)
 
     for (dl = mem_alloclist.Mnext; dl != NULL; dl = dl->Mnext)
     {
-        if (p >= (void *) &(dl->data[0]) &&
+        if (p >=  &(dl->tdata()[0]) &&
             p < (void *)((char *)dl + sizeof(struct mem_debug)-1 + dl->Mnbytes))
             goto L1;
     }
diff --git a/src/tocsym.c b/src/tocsym.c
index 43eec3ebd707..ef7fc475be0f 100644
--- a/src/tocsym.c
+++ b/src/tocsym.c
@@ -785,7 +785,7 @@ Symbol *TypeAArray::aaGetSymbol(const char *func, int flags)
 
         // See if symbol is already in sarray
         for (i = 0; i < sarray->dim; i++)
-        {   s = (Symbol *)sarray->data[i];
+        {   s = sarray->tdata()[i];
             if (strcmp(id, s->Sident) == 0)
                 return s;                       // use existing Symbol
         }
diff --git a/src/toctype.c b/src/toctype.c
index ddc181a2f3bb..6a3c49589269 100644
--- a/src/toctype.c
+++ b/src/toctype.c
@@ -378,7 +378,7 @@ type *TypeStruct::toCtype()
          */
         if (global.params.symdebug)
             for (int i = 0; i < sym->fields.dim; i++)
-            {   VarDeclaration *v = (VarDeclaration *)sym->fields.data[i];
+            {   VarDeclaration *v = sym->fields.tdata()[i];
 
                 Symbol *s2 = symbol_name(v->ident->toChars(), SCmember, v->type->toCtype());
                 s2->Smemoff = v->offset;
@@ -505,7 +505,7 @@ type *TypeClass::toCtype()
      */
     if (global.params.symdebug)
         for (int i = 0; i < sym->fields.dim; i++)
-        {   VarDeclaration *v = (VarDeclaration *)sym->fields.data[i];
+        {   VarDeclaration *v = sym->fields.tdata()[i];
 
             Symbol *s2 = symbol_name(v->ident->toChars(), SCmember, v->type->toCtype());
             s2->Smemoff = v->offset;
diff --git a/src/tocvdebug.c b/src/tocvdebug.c
index 14ad2a7a730a..3311f16c26c7 100644
--- a/src/tocvdebug.c
+++ b/src/tocvdebug.c
@@ -148,7 +148,7 @@ unsigned cv4_Denum(EnumDeclaration *e)
     if (e->members)
     {
         for (i = 0; i < e->members->dim; i++)
-        {   EnumMember *sf = ((Dsymbol *)e->members->data[i])->isEnumMember();
+        {   EnumMember *sf = (e->members->tdata()[i])->isEnumMember();
             dinteger_t value;
 
             if (sf)
@@ -187,7 +187,7 @@ unsigned cv4_Denum(EnumDeclaration *e)
     int j = 2;
     int fieldi = 0;
     for (i = 0; i < e->members->dim; i++)
-    {   EnumMember *sf = ((Dsymbol *)e->members->data[i])->isEnumMember();
+    {   EnumMember *sf = (e->members->tdata()[i])->isEnumMember();
         dinteger_t value;
 
         if (sf)
@@ -363,7 +363,7 @@ void StructDeclaration::toDebug()
 
     count = nfields;
     for (i = 0; i < members->dim; i++)
-    {   Dsymbol *s = (Dsymbol *)members->data[i];
+    {   Dsymbol *s = members->tdata()[i];
         int nwritten;
 
         nwritten = s->cvMember(NULL);
@@ -386,7 +386,7 @@ void StructDeclaration::toDebug()
     TOWORD(p,LF_FIELDLIST);
     p += 2;
     for (i = 0; i < members->dim; i++)
-    {   Dsymbol *s = (Dsymbol *)members->data[i];
+    {   Dsymbol *s = members->tdata()[i];
 
         p += s->cvMember(p);
     }
@@ -496,7 +496,7 @@ void ClassDeclaration::toDebug()
 
                 //if (intsize == 4)
                     descriptor |= 5;
-                vshape->data[4 + n / 2] = descriptor;
+                vshape->tdata()[4 + n / 2] = descriptor;
                 descriptor <<= 4;
                 n++;
             }
@@ -528,7 +528,7 @@ void ClassDeclaration::toDebug()
 
     // Add in base classes
     for (i = 0; i < baseclasses->dim; i++)
-    {   BaseClass *bc = (BaseClass *)baseclasses->data[i];
+    {   BaseClass *bc = baseclasses->tdata()[i];
 
         nfields++;
         fnamelen += 6 + cv4_numericbytes(bc->offset);
@@ -536,7 +536,7 @@ void ClassDeclaration::toDebug()
 
     count = nfields;
     for (i = 0; i < members->dim; i++)
-    {   Dsymbol *s = (Dsymbol *)members->data[i];
+    {   Dsymbol *s = members->tdata()[i];
         int nwritten;
 
         nwritten = s->cvMember(NULL);
@@ -561,7 +561,7 @@ void ClassDeclaration::toDebug()
 
     // Add in base classes
     for (i = 0; i < baseclasses->dim; i++)
-    {   BaseClass *bc = (BaseClass *)baseclasses->data[i];
+    {   BaseClass *bc = baseclasses->tdata()[i];
         idx_t typidx;
         unsigned attribute;
 
@@ -581,7 +581,7 @@ void ClassDeclaration::toDebug()
 
 
     for (i = 0; i < members->dim; i++)
-    {   Dsymbol *s = (Dsymbol *)members->data[i];
+    {   Dsymbol *s = members->tdata()[i];
 
         p += s->cvMember(p);
     }
diff --git a/src/todt.c b/src/todt.c
index 1dcee1f77c8a..b45338412536 100644
--- a/src/todt.c
+++ b/src/todt.c
@@ -80,20 +80,20 @@ dt_t *StructInitializer::toDt()
 
     for (i = 0; i < vars.dim; i++)
     {
-        VarDeclaration *v = (VarDeclaration *)vars.data[i];
-        Initializer *val = (Initializer *)value.data[i];
+        VarDeclaration *v = vars.tdata()[i];
+        Initializer *val = value.tdata()[i];
 
         //printf("vars[%d] = %s\n", i, v->toChars());
 
         for (j = 0; 1; j++)
         {
             assert(j < dts.dim);
-            //printf(" adfield[%d] = %s\n", j, ((VarDeclaration *)ad->fields.data[j])->toChars());
-            if ((VarDeclaration *)ad->fields.data[j] == v)
+            //printf(" adfield[%d] = %s\n", j, (ad->fields.tdata()[j])->toChars());
+            if (ad->fields.tdata()[j] == v)
             {
-                if (dts.data[j])
+                if (dts.tdata()[j])
                     error(loc, "field %s of %s already initialized", v->toChars(), ad->toChars());
-                dts.data[j] = (void *)val->toDt();
+                dts.tdata()[j] = val->toDt();
                 break;
             }
         }
@@ -104,14 +104,14 @@ dt_t *StructInitializer::toDt()
     offset = 0;
     for (j = 0; j < dts.dim; j++)
     {
-        VarDeclaration *v = (VarDeclaration *)ad->fields.data[j];
+        VarDeclaration *v = ad->fields.tdata()[j];
 
-        d = (dt_t *)dts.data[j];
+        d = dts.tdata()[j];
         if (!d)
         {   // An instance specific initializer was not provided.
             // Look to see if there's a default initializer from the
             // struct definition
-            VarDeclaration *v = (VarDeclaration *)ad->fields.data[j];
+            VarDeclaration *v = ad->fields.tdata()[j];
 
             if (v->init)
             {
@@ -130,9 +130,9 @@ dt_t *StructInitializer::toDt()
                         v->type->toDt(&d);
                         break;
                     }
-                    VarDeclaration *v2 = (VarDeclaration *)ad->fields.data[k];
+                    VarDeclaration *v2 = ad->fields.tdata()[k];
 
-                    if (v2->offset < offset2 && dts.data[k])
+                    if (v2->offset < offset2 && dts.tdata()[k])
                         break;                  // overlap
                 }
             }
@@ -214,17 +214,17 @@ dt_t *ArrayInitializer::toDt()
     {   Expression *idx;
         Initializer *val;
 
-        idx = (Expression *)index.data[i];
+        idx = index.tdata()[i];
         if (idx)
             length = idx->toInteger();
         //printf("\tindex[%d] = %p, length = %u, dim = %u\n", i, idx, length, dim);
 
         assert(length < dim);
-        val = (Initializer *)value.data[i];
+        val = value.tdata()[i];
         dt = val->toDt();
-        if (dts.data[length])
+        if (dts.tdata()[length])
             error(loc, "duplicate initializations for index %d", length);
-        dts.data[length] = (void *)dt;
+        dts.tdata()[length] = dt;
         length++;
     }
 
@@ -241,7 +241,7 @@ dt_t *ArrayInitializer::toDt()
     pdtend = &d;
     for (i = 0; i < dim; i++)
     {
-        dt = (dt_t *)dts.data[i];
+        dt = dts.tdata()[i];
         if (dt)
             pdtend = dtcat(pdtend, dt);
         else
@@ -341,7 +341,7 @@ dt_t *ArrayInitializer::toDtBit()
     if (tb->nextOf()->defaultInit()->toInteger())
        databits.set();
 
-    size = sizeof(databits.data[0]);
+    size = sizeof(databits.tdata()[0]);
 
     length = 0;
     for (i = 0; i < index.dim; i++)
@@ -349,7 +349,7 @@ dt_t *ArrayInitializer::toDtBit()
         Initializer *val;
         Expression *eval;
 
-        idx = (Expression *)index.data[i];
+        idx = index.tdata()[i];
         if (idx)
         {   dinteger_t value;
             value = idx->toInteger();
@@ -361,7 +361,7 @@ dt_t *ArrayInitializer::toDtBit()
         }
         assert(length < dim);
 
-        val = (Initializer *)value.data[i];
+        val = value.tdata()[i];
         eval = val->toExpression();
         if (initbits.test(length))
             error(loc, "duplicate initializations for index %d", length);
@@ -589,7 +589,7 @@ dt_t **ArrayLiteralExp::toDt(dt_t **pdt)
     d = NULL;
     pdtend = &d;
     for (int i = 0; i < elements->dim; i++)
-    {   Expression *e = (Expression *)elements->data[i];
+    {   Expression *e = elements->tdata()[i];
 
         pdtend = e->toDt(pdtend);
     }
@@ -642,25 +642,25 @@ dt_t **StructLiteralExp::toDt(dt_t **pdt)
 
     for (i = 0; i < elements->dim; i++)
     {
-        Expression *e = (Expression *)elements->data[i];
+        Expression *e = elements->tdata()[i];
         if (!e)
             continue;
         dt = NULL;
         e->toDt(&dt);
-        dts.data[i] = (void *)dt;
+        dts.tdata()[i] = dt;
     }
 
     offset = 0;
     for (j = 0; j < dts.dim; j++)
     {
-        VarDeclaration *v = (VarDeclaration *)sd->fields.data[j];
+        VarDeclaration *v = sd->fields.tdata()[j];
 
-        d = (dt_t *)dts.data[j];
+        d = dts.tdata()[j];
         if (!d)
         {   // An instance specific initializer was not provided.
             // Look to see if there's a default initializer from the
             // struct definition
-            VarDeclaration *v = (VarDeclaration *)sd->fields.data[j];
+            VarDeclaration *v = sd->fields.tdata()[j];
 
             if (v->init)
             {
@@ -679,9 +679,9 @@ dt_t **StructLiteralExp::toDt(dt_t **pdt)
                         v->type->toDt(&d);
                         break;
                     }
-                    VarDeclaration *v2 = (VarDeclaration *)sd->fields.data[k];
+                    VarDeclaration *v2 = sd->fields.tdata()[k];
 
-                    if (v2->offset < offset2 && dts.data[k])
+                    if (v2->offset < offset2 && dts.tdata()[k])
                         break;                  // overlap
                 }
             }
@@ -836,7 +836,7 @@ void ClassDeclaration::toDt2(dt_t **pdt, ClassDeclaration *cd)
     // Note equivalence of this loop to struct's
     for (i = 0; i < fields.dim; i++)
     {
-        VarDeclaration *v = (VarDeclaration *)fields.data[i];
+        VarDeclaration *v = fields.tdata()[i];
         Initializer *init;
 
         //printf("\t\tv = '%s' v->offset = %2d, offset = %2d\n", v->toChars(), v->offset, offset);
@@ -873,7 +873,7 @@ void ClassDeclaration::toDt2(dt_t **pdt, ClassDeclaration *cd)
     toSymbol();                                         // define csym
 
     for (i = 0; i < vtblInterfaces->dim; i++)
-    {   BaseClass *b = (BaseClass *)vtblInterfaces->data[i];
+    {   BaseClass *b = vtblInterfaces->tdata()[i];
 
 #if 1 || INTERFACE_VIRTUAL
         for (ClassDeclaration *cd2 = cd; 1; cd2 = cd2->baseClass)
@@ -914,7 +914,7 @@ void StructDeclaration::toDt(dt_t **pdt)
     // Note equivalence of this loop to class's
     for (i = 0; i < fields.dim; i++)
     {
-        VarDeclaration *v = (VarDeclaration *)fields.data[i];
+        VarDeclaration *v = fields.tdata()[i];
         //printf("\tfield '%s' voffset %d, offset = %d\n", v->toChars(), v->offset, offset);
         dt = NULL;
         int sz;
diff --git a/src/toir.c b/src/toir.c
index 79c698a8e526..819f0af60918 100644
--- a/src/toir.c
+++ b/src/toir.c
@@ -732,7 +732,7 @@ void FuncDeclaration::buildClosure(IRState *irs)
 
         unsigned offset = PTRSIZE;      // leave room for previous sthis
         for (int i = 0; i < closureVars.dim; i++)
-        {   VarDeclaration *v = (VarDeclaration *)closureVars.data[i];
+        {   VarDeclaration *v = closureVars.tdata()[i];
             assert(v->isVarDeclaration());
 
 #if DMDV2
@@ -812,7 +812,7 @@ void FuncDeclaration::buildClosure(IRState *irs)
 
         // Copy function parameters into closure
         for (int i = 0; i < closureVars.dim; i++)
-        {   VarDeclaration *v = (VarDeclaration *)closureVars.data[i];
+        {   VarDeclaration *v = closureVars.tdata()[i];
 
             if (!v->isParameter())
                 continue;
diff --git a/src/toobj.c b/src/toobj.c
index eac158e4ed3e..dc4cbf2708e0 100644
--- a/src/toobj.c
+++ b/src/toobj.c
@@ -69,7 +69,7 @@ void Module::genmoduleinfo()
 
     //printf("members->dim = %d\n", members->dim);
     for (int i = 0; i < members->dim; i++)
-    {   Dsymbol *member = (Dsymbol *)members->data[i];
+    {   Dsymbol *member = members->tdata()[i];
 
         //printf("\tmember '%s'\n", member->toChars());
         member->addLocalClass(&aclasses);
@@ -78,7 +78,7 @@ void Module::genmoduleinfo()
     // importedModules[]
     int aimports_dim = aimports.dim;
     for (int i = 0; i < aimports.dim; i++)
-    {   Module *m = (Module *)aimports.data[i];
+    {   Module *m = aimports.tdata()[i];
         if (!m->needmoduleinfo)
             aimports_dim--;
     }
@@ -142,7 +142,7 @@ void Module::genmoduleinfo()
     {
         dtsize_t(&dt, aimports_dim);
         for (int i = 0; i < aimports.dim; i++)
-        {   Module *m = (Module *)aimports.data[i];
+        {   Module *m = aimports.tdata()[i];
 
             if (m->needmoduleinfo)
             {   Symbol *s = m->toSymbol();
@@ -163,7 +163,7 @@ void Module::genmoduleinfo()
         dtsize_t(&dt, aclasses.dim);
         for (int i = 0; i < aclasses.dim; i++)
         {
-            ClassDeclaration *cd = (ClassDeclaration *)aclasses.data[i];
+            ClassDeclaration *cd = aclasses.tdata()[i];
             dtxoff(&dt, cd->toSymbol(), 0, TYnptr);
         }
     }
@@ -216,7 +216,7 @@ void Module::genmoduleinfo()
 
     //printf("members->dim = %d\n", members->dim);
     for (int i = 0; i < members->dim; i++)
-    {   Dsymbol *member = (Dsymbol *)members->data[i];
+    {   Dsymbol *member = members->tdata()[i];
 
         //printf("\tmember '%s'\n", member->toChars());
         member->addLocalClass(&aclasses);
@@ -225,7 +225,7 @@ void Module::genmoduleinfo()
     // importedModules[]
     int aimports_dim = aimports.dim;
     for (int i = 0; i < aimports.dim; i++)
-    {   Module *m = (Module *)aimports.data[i];
+    {   Module *m = aimports.tdata()[i];
         if (!m->needModuleInfo())
             aimports_dim--;
     }
@@ -294,7 +294,7 @@ void Module::genmoduleinfo()
     //////////////////////////////////////////////
 
     for (int i = 0; i < aimports.dim; i++)
-    {   Module *m = (Module *)aimports.data[i];
+    {   Module *m = aimports.tdata()[i];
 
         if (m->needModuleInfo())
         {   Symbol *s = m->toSymbol();
@@ -312,7 +312,7 @@ void Module::genmoduleinfo()
 
     for (int i = 0; i < aclasses.dim; i++)
     {
-        ClassDeclaration *cd = (ClassDeclaration *)aclasses.data[i];
+        ClassDeclaration *cd = aclasses.data()[i];
         dtxoff(&dt, cd->toSymbol(), 0, TYnptr);
     }
 #endif
@@ -369,7 +369,7 @@ void ClassDeclaration::toObjFile(int multiobj)
     {
         Dsymbol *member;
 
-        member = (Dsymbol *)members->data[i];
+        member = members->tdata()[i];
         member->toObjFile(0);
     }
 
@@ -384,7 +384,7 @@ void ClassDeclaration::toObjFile(int multiobj)
 
         case 1:
             // One destructor, just use it directly
-            sdtor = ((DtorDeclaration *)dtors.data[0])->toSymbol();
+            sdtor = dtors.tdata()[0]->toSymbol();
             break;
 
         default:
@@ -405,7 +405,7 @@ void ClassDeclaration::toObjFile(int multiobj)
             // Call each of the destructors in dtors[]
             // in reverse order
             for (i = 0; i < dtors.dim; i++)
-            {   DtorDeclaration *d = (DtorDeclaration *)dtors.data[i];
+            {   DtorDeclaration *d = dtors.tdata()[i];
                 Symbol *s = d->toSymbol();
                 elem *e = el_bin(OPcall, TYvoid, el_var(s), el_var(sthis));
                 edtor = el_combine(e, edtor);
@@ -561,7 +561,7 @@ void ClassDeclaration::toObjFile(int multiobj)
         {
             for (size_t i = 0; i < cd->members->dim; i++)
             {
-                Dsymbol *sm = (Dsymbol *)cd->members->data[i];
+                Dsymbol *sm = cd->members->tdata()[i];
                 //printf("sm = %s %s\n", sm->kind(), sm->toChars());
                 if (sm->hasPointers())
                     goto L2;
@@ -601,12 +601,12 @@ void ClassDeclaration::toObjFile(int multiobj)
 
     //////////////////////////////////////////////
 
-    // Put out vtblInterfaces->data[]. Must immediately follow csym, because
+    // Put out vtblInterfaces->tdata()[]. Must immediately follow csym, because
     // of the fixup (*)
 
     offset += vtblInterfaces->dim * (4 * PTRSIZE);
     for (i = 0; i < vtblInterfaces->dim; i++)
-    {   BaseClass *b = (BaseClass *)vtblInterfaces->data[i];
+    {   BaseClass *b = vtblInterfaces->tdata()[i];
         ClassDeclaration *id = b->base;
 
         /* The layout is:
@@ -632,11 +632,11 @@ void ClassDeclaration::toObjFile(int multiobj)
         offset += id->vtbl.dim * PTRSIZE;
     }
 
-    // Put out the vtblInterfaces->data[].vtbl[]
+    // Put out the vtblInterfaces->tdata()[].vtbl[]
     // This must be mirrored with ClassDeclaration::baseVtblOffset()
     //printf("putting out %d interface vtbl[]s for '%s'\n", vtblInterfaces->dim, toChars());
     for (i = 0; i < vtblInterfaces->dim; i++)
-    {   BaseClass *b = (BaseClass *)vtblInterfaces->data[i];
+    {   BaseClass *b = vtblInterfaces->tdata()[i];
         ClassDeclaration *id = b->base;
 
         //printf("    interface[%d] is '%s'\n", i, id->toChars());
@@ -655,7 +655,7 @@ void ClassDeclaration::toObjFile(int multiobj)
         {
             assert(j < b->vtbl.dim);
 #if 0
-            Object *o = (Object *)b->vtbl.data[j];
+            Object *o = b->vtbl.tdata()[j];
             if (o)
             {
                 printf("o = %p\n", o);
@@ -664,7 +664,7 @@ void ClassDeclaration::toObjFile(int multiobj)
                 printf("s->kind() = '%s'\n", s->kind());
             }
 #endif
-            FuncDeclaration *fd = (FuncDeclaration *)b->vtbl.data[j];
+            FuncDeclaration *fd = b->vtbl.tdata()[j];
             if (fd)
                 dtxoff(&dt, fd->toThunkSymbol(b->offset), 0, TYnptr);
             else
@@ -682,7 +682,7 @@ void ClassDeclaration::toObjFile(int multiobj)
     for (cd = this->baseClass; cd; cd = cd->baseClass)
     {
         for (int k = 0; k < cd->vtblInterfaces->dim; k++)
-        {   BaseClass *bs = (BaseClass *)cd->vtblInterfaces->data[k];
+        {   BaseClass *bs = cd->vtblInterfaces->tdata()[k];
 
             if (bs->fillVtbl(this, &bvtbl, 0))
             {
@@ -705,7 +705,7 @@ void ClassDeclaration::toObjFile(int multiobj)
                     FuncDeclaration *fd;
 
                     assert(j < bvtbl.dim);
-                    fd = (FuncDeclaration *)bvtbl.data[j];
+                    fd = bvtbl.tdata()[j];
                     if (fd)
                         dtxoff(&dt, fd->toThunkSymbol(bs->offset), 0, TYnptr);
                     else
@@ -720,13 +720,13 @@ void ClassDeclaration::toObjFile(int multiobj)
     // This must be mirrored with ClassDeclaration::baseVtblOffset()
     //printf("putting out overriding interface vtbl[]s for '%s' at offset x%x\n", toChars(), offset);
     for (i = 0; i < vtblInterfaces->dim; i++)
-    {   BaseClass *b = (BaseClass *)vtblInterfaces->data[i];
+    {   BaseClass *b = vtblInterfaces->tdata()[i];
         ClassDeclaration *cd;
 
         for (cd = this->baseClass; cd; cd = cd->baseClass)
         {
             for (int k = 0; k < cd->vtblInterfaces->dim; k++)
-            {   BaseClass *bs = (BaseClass *)cd->vtblInterfaces->data[k];
+            {   BaseClass *bs = cd->vtblInterfaces->tdata()[k];
 
                 if (b->base == bs->base)
                 {
@@ -747,7 +747,7 @@ void ClassDeclaration::toObjFile(int multiobj)
                     for (; j < id->vtbl.dim; j++)
                     {
                         assert(j < b->vtbl.dim);
-                        FuncDeclaration *fd = (FuncDeclaration *)b->vtbl.data[j];
+                        FuncDeclaration *fd = b->vtbl.tdata()[j];
                         if (fd)
                             dtxoff(&dt, fd->toThunkSymbol(bs->offset), 0, TYnptr);
                         else
@@ -782,7 +782,7 @@ void ClassDeclaration::toObjFile(int multiobj)
     }
     for (; i < vtbl.dim; i++)
     {
-        FuncDeclaration *fd = ((Dsymbol *)vtbl.data[i])->isFuncDeclaration();
+        FuncDeclaration *fd = vtbl.tdata()[i]->isFuncDeclaration();
 
         //printf("\tvtbl[%d] = %p\n", i, fd);
         if (fd && (fd->fbody || !isAbstract()))
@@ -805,7 +805,7 @@ void ClassDeclaration::toObjFile(int multiobj)
                 for (int j = 1; j < vtbl.dim; j++)
                 {   if (j == i)
                         continue;
-                    FuncDeclaration *fd2 = ((Dsymbol *)vtbl.data[j])->isFuncDeclaration();
+                    FuncDeclaration *fd2 = vtbl.tdata()[j]->isFuncDeclaration();
                     if (!fd2->ident->equals(fd->ident))
                         continue;
                     if (fd->leastAsSpecialized(fd2) || fd2->leastAsSpecialized(fd))
@@ -859,7 +859,7 @@ unsigned ClassDeclaration::baseVtblOffset(BaseClass *bc)
 
     for (i = 0; i < vtblInterfaces->dim; i++)
     {
-        BaseClass *b = (BaseClass *)vtblInterfaces->data[i];
+        BaseClass *b = vtblInterfaces->tdata()[i];
 
         if (b == bc)
             return csymoffset;
@@ -876,7 +876,7 @@ unsigned ClassDeclaration::baseVtblOffset(BaseClass *bc)
     for (cd = this->baseClass; cd; cd = cd->baseClass)
     {
         for (int k = 0; k < cd->vtblInterfaces->dim; k++)
-        {   BaseClass *bs = (BaseClass *)cd->vtblInterfaces->data[k];
+        {   BaseClass *bs = cd->vtblInterfaces->tdata()[k];
 
             if (bs->fillVtbl(this, NULL, 0))
             {
@@ -891,14 +891,14 @@ unsigned ClassDeclaration::baseVtblOffset(BaseClass *bc)
 #endif
 #if INTERFACE_VIRTUAL
     for (i = 0; i < vtblInterfaces->dim; i++)
-    {   BaseClass *b = (BaseClass *)vtblInterfaces->data[i];
+    {   BaseClass *b = vtblInterfaces->tdata()[i];
         ClassDeclaration *cd;
 
         for (cd = this->baseClass; cd; cd = cd->baseClass)
         {
             //printf("\tbase class %s\n", cd->toChars());
             for (int k = 0; k < cd->vtblInterfaces->dim; k++)
-            {   BaseClass *bs = (BaseClass *)cd->vtblInterfaces->data[k];
+            {   BaseClass *bs = cd->vtblInterfaces->tdata()[k];
 
                 if (bc == bs)
                 {   //printf("\tcsymoffset = x%x\n", csymoffset);
@@ -935,7 +935,7 @@ void InterfaceDeclaration::toObjFile(int multiobj)
 
     // Put out the members
     for (i = 0; i < members->dim; i++)
-    {   Dsymbol *member = (Dsymbol *)members->data[i];
+    {   Dsymbol *member = members->tdata()[i];
 
         member->toObjFile(0);
     }
@@ -998,7 +998,7 @@ void InterfaceDeclaration::toObjFile(int multiobj)
     dtsize_t(&dt, 0);
     dtsize_t(&dt, 0);
 
-    // vtblInterfaces->data[]
+    // vtblInterfaces->tdata()[]
     unsigned offset;
     dtsize_t(&dt, vtblInterfaces->dim);
     if (vtblInterfaces->dim)
@@ -1051,12 +1051,12 @@ void InterfaceDeclaration::toObjFile(int multiobj)
 
     //////////////////////////////////////////////
 
-    // Put out vtblInterfaces->data[]. Must immediately follow csym, because
+    // Put out vtblInterfaces->tdata()[]. Must immediately follow csym, because
     // of the fixup (*)
 
     offset += vtblInterfaces->dim * (4 * PTRSIZE);
     for (i = 0; i < vtblInterfaces->dim; i++)
-    {   BaseClass *b = (BaseClass *)vtblInterfaces->data[i];
+    {   BaseClass *b = vtblInterfaces->tdata()[i];
         ClassDeclaration *id = b->base;
 
         // ClassInfo
@@ -1156,7 +1156,7 @@ void StructDeclaration::toObjFile(int multiobj)
         {
             Dsymbol *member;
 
-            member = (Dsymbol *)members->data[i];
+            member = members->tdata()[i];
             member->toObjFile(0);
         }
     }
diff --git a/src/traits.c b/src/traits.c
index e3e18b5a9685..1f8684bb5033 100644
--- a/src/traits.c
+++ b/src/traits.c
@@ -88,7 +88,7 @@ Expression *TraitsExp::semantic(Scope *sc)
 
 #define ISTYPE(cond) \
         for (size_t i = 0; i < dim; i++)        \
-        {   Type *t = getType((Object *)args->data[i]); \
+        {   Type *t = getType(args->tdata()[i]); \
             if (!t)                             \
                 goto Lfalse;                    \
             if (!(cond))                        \
@@ -100,7 +100,7 @@ Expression *TraitsExp::semantic(Scope *sc)
 
 #define ISDSYMBOL(cond) \
         for (size_t i = 0; i < dim; i++)        \
-        {   Dsymbol *s = getDsymbol((Object *)args->data[i]);   \
+        {   Dsymbol *s = getDsymbol(args->tdata()[i]);   \
             if (!s)                             \
                 goto Lfalse;                    \
             if (!(cond))                        \
@@ -186,7 +186,7 @@ Expression *TraitsExp::semantic(Scope *sc)
 
         if (dim != 1)
             goto Ldimerror;
-        Object *o = (Object *)args->data[0];
+        Object *o = args->tdata()[0];
         Dsymbol *s = getDsymbol(o);
         if (!s || !s->ident)
         {
@@ -200,7 +200,7 @@ Expression *TraitsExp::semantic(Scope *sc)
     {
         if (dim != 1)
             goto Ldimerror;
-        Object *o = (Object *)args->data[0];
+        Object *o = args->tdata()[0];
         Dsymbol *s = getDsymbol(o);
         if (s)
             s = s->toParent();
@@ -220,8 +220,8 @@ Expression *TraitsExp::semantic(Scope *sc)
     {
         if (dim != 2)
             goto Ldimerror;
-        Object *o = (Object *)args->data[0];
-        Expression *e = isExpression((Object *)args->data[1]);
+        Object *o = args->tdata()[0];
+        Expression *e = isExpression(args->tdata()[1]);
         if (!e)
         {   error("expression expected as second argument of __traits %s", ident->toChars());
             goto Lfalse;
@@ -312,7 +312,7 @@ Expression *TraitsExp::semantic(Scope *sc)
     {
         if (dim != 1)
             goto Ldimerror;
-        Object *o = (Object *)args->data[0];
+        Object *o = args->tdata()[0];
         Dsymbol *s = getDsymbol(o);
         ClassDeclaration *cd;
         if (!s || (cd = s->isClassDeclaration()) == NULL)
@@ -326,7 +326,7 @@ Expression *TraitsExp::semantic(Scope *sc)
     {
         if (dim != 1)
             goto Ldimerror;
-        Object *o = (Object *)args->data[0];
+        Object *o = args->tdata()[0];
         Dsymbol *s = getDsymbol(o);
         ScopeDsymbol *sd;
         if (!s)
@@ -354,7 +354,7 @@ Expression *TraitsExp::semantic(Scope *sc)
                     /* Skip if already present in exps[]
                      */
                     for (size_t j = 0; j < exps->dim; j++)
-                    {   StringExp *se2 = (StringExp *)exps->data[j];
+                    {   StringExp *se2 = (StringExp *)exps->tdata()[j];
                         if (strcmp(str, (char *)se2->string) == 0)
                             goto Lnext;
                     }
@@ -393,7 +393,7 @@ Expression *TraitsExp::semantic(Scope *sc)
             goto Lfalse;
 
         for (size_t i = 0; i < dim; i++)
-        {   Object *o = (Object *)args->data[i];
+        {   Object *o = args->tdata()[i];
             Expression *e;
 
             unsigned errors = global.errors;
@@ -433,8 +433,8 @@ Expression *TraitsExp::semantic(Scope *sc)
         if (dim != 2)
             goto Ldimerror;
         TemplateInstance::semanticTiargs(loc, sc, args, 0);
-        Object *o1 = (Object *)args->data[0];
-        Object *o2 = (Object *)args->data[1];
+        Object *o1 = args->tdata()[0];
+        Object *o2 = args->tdata()[1];
         Dsymbol *s1 = getDsymbol(o1);
         Dsymbol *s2 = getDsymbol(o2);
 
diff --git a/src/typinf.c b/src/typinf.c
index b07235fa24be..e6a96779d840 100644
--- a/src/typinf.c
+++ b/src/typinf.c
@@ -641,7 +641,7 @@ void TypeInfoStructDeclaration::toDt(dt_t **pdt)
         {
             if (i < tup->arguments->dim)
             {
-                Type *targ = ((Parameter *)tup->arguments->data[i])->type;
+                Type *targ = (tup->arguments->tdata()[i])->type;
                 targ = targ->merge();
                 targ->getTypeInfo(NULL);
                 dtxoff(pdt, targ->vtinfo->toSymbol(), 0, TYnptr);       // m_argi
@@ -712,7 +712,7 @@ void TypeInfoTupleDeclaration::toDt(dt_t **pdt)
 
     dt_t *d = NULL;
     for (size_t i = 0; i < dim; i++)
-    {   Parameter *arg = (Parameter *)tu->arguments->data[i];
+    {   Parameter *arg = tu->arguments->tdata()[i];
         Expression *e = arg->type->getTypeInfo(NULL);
         e = e->optimize(WANTvalue);
         e->toDt(&d);
@@ -839,7 +839,7 @@ Expression *createTypeInfoArray(Scope *sc, Expression *exps[], int dim)
     args->setDim(dim);
     for (size_t i = 0; i < dim; i++)
     {   Parameter *arg = new Parameter(STCin, exps[i]->type, NULL, NULL);
-        args->data[i] = (void *)arg;
+        args->tdata()[i] = arg;
     }
     TypeTuple *tup = new TypeTuple(args);
     Expression *e = tup->getTypeInfo(sc);
diff --git a/src/version.c b/src/version.c
index d4a48dd8989f..37f33c066e14 100644
--- a/src/version.c
+++ b/src/version.c
@@ -63,7 +63,7 @@ int DebugSymbol::addMember(Scope *sc, ScopeDsymbol *sd, int memnum)
             if (findCondition(m->debugidsNot, ident))
                 error("defined after use");
             if (!m->debugids)
-                m->debugids = new Identifiers();
+                m->debugids = new Strings();
             m->debugids->push(ident->toChars());
         }
     }
@@ -144,7 +144,7 @@ int VersionSymbol::addMember(Scope *sc, ScopeDsymbol *sd, int memnum)
             if (findCondition(m->versionidsNot, ident))
                 error("defined after use");
             if (!m->versionids)
-                m->versionids = new Identifiers();
+                m->versionids = new Strings();
             m->versionids->push(ident->toChars());
         }
     }