Rollup of 10 pull requests

compiler/rustc_ast/src/ast.rs

@@ -175,9 +175,9 @@ impl GenericArgs {
     }
 
     pub fn span(&self) -> Span {
-        match *self {
-            AngleBracketed(ref data) => data.span,
-            Parenthesized(ref data) => data.span,
+        match self {
+            AngleBracketed(data) => data.span,
+            Parenthesized(data) => data.span,
         }
     }
 }
@@ -312,8 +312,8 @@ pub enum GenericBound {
 impl GenericBound {
     pub fn span(&self) -> Span {
         match self {
-            GenericBound::Trait(ref t, ..) => t.span,
-            GenericBound::Outlives(ref l) => l.ident.span,
+            GenericBound::Trait(t, ..) => t.span,
+            GenericBound::Outlives(l) => l.ident.span,
         }
     }
 }
@@ -1115,23 +1115,23 @@ impl Expr {
     /// If this is not the case, name resolution does not resolve `N` when using
     /// `min_const_generics` as more complex expressions are not supported.
     pub fn is_potential_trivial_const_param(&self) -> bool {
-        let this = if let ExprKind::Block(ref block, None) = self.kind {
-            if block.stmts.len() == 1 {
-                if let StmtKind::Expr(ref expr) = block.stmts[0].kind { expr } else { self }
-            } else {
-                self
-            }
+        let this = if let ExprKind::Block(block, None) = &self.kind
+            && block.stmts.len() == 1
+            && let StmtKind::Expr(expr) = &block.stmts[0].kind
+        {
+            expr
         } else {
             self
         };
 
-        if let ExprKind::Path(None, ref path) = this.kind {
-            if path.segments.len() == 1 && path.segments[0].args.is_none() {
-                return true;
-            }
+        if let ExprKind::Path(None, path) = &this.kind
+            && path.segments.len() == 1
+            && path.segments[0].args.is_none()
+        {
+            true
+        } else {
+            false
         }
-
-        false
     }
 
     pub fn to_bound(&self) -> Option<GenericBound> {
@@ -2393,9 +2393,9 @@ pub enum FnRetTy {
 
 impl FnRetTy {
     pub fn span(&self) -> Span {
-        match *self {
-            FnRetTy::Default(span) => span,
-            FnRetTy::Ty(ref ty) => ty.span,
+        match self {
+            &FnRetTy::Default(span) => span,
+            FnRetTy::Ty(ty) => ty.span,
         }
     }
 }
@@ -2657,8 +2657,8 @@ pub enum VariantData {
 impl VariantData {
     /// Return the fields of this variant.
     pub fn fields(&self) -> &[FieldDef] {
-        match *self {
-            VariantData::Struct(ref fields, ..) | VariantData::Tuple(ref fields, _) => fields,
+        match self {
+            VariantData::Struct(fields, ..) | VariantData::Tuple(fields, _) => fields,
             _ => &[],
         }
     }

compiler/rustc_ast/src/attr/mod.rs

@@ -44,16 +44,16 @@ impl MarkedAttrs {
 impl NestedMetaItem {
     /// Returns the `MetaItem` if `self` is a `NestedMetaItem::MetaItem`.
     pub fn meta_item(&self) -> Option<&MetaItem> {
-        match *self {
-            NestedMetaItem::MetaItem(ref item) => Some(item),
+        match self {
+            NestedMetaItem::MetaItem(item) => Some(item),
             _ => None,
         }
     }
 
     /// Returns the `Lit` if `self` is a `NestedMetaItem::Literal`s.
     pub fn literal(&self) -> Option<&Lit> {
-        match *self {
-            NestedMetaItem::Literal(ref lit) => Some(lit),
+        match self {
+            NestedMetaItem::Literal(lit) => Some(lit),
             _ => None,
         }
     }
@@ -116,18 +116,18 @@ impl NestedMetaItem {
 impl Attribute {
     #[inline]
     pub fn has_name(&self, name: Symbol) -> bool {
-        match self.kind {
-            AttrKind::Normal(ref normal) => normal.item.path == name,
+        match &self.kind {
+            AttrKind::Normal(normal) => normal.item.path == name,
             AttrKind::DocComment(..) => false,
         }
     }
 
     /// For a single-segment attribute, returns its name; otherwise, returns `None`.
     pub fn ident(&self) -> Option<Ident> {
-        match self.kind {
-            AttrKind::Normal(ref normal) => {
-                if normal.item.path.segments.len() == 1 {
-                    Some(normal.item.path.segments[0].ident)
+        match &self.kind {
+            AttrKind::Normal(normal) => {
+                if let [ident] = &*normal.item.path.segments {
+                    Some(ident.ident)
                 } else {
                     None
                 }
@@ -140,17 +140,15 @@ impl Attribute {
     }
 
     pub fn value_str(&self) -> Option<Symbol> {
-        match self.kind {
-            AttrKind::Normal(ref normal) => {
-                normal.item.meta_kind().and_then(|kind| kind.value_str())
-            }
+        match &self.kind {
+            AttrKind::Normal(normal) => normal.item.meta_kind().and_then(|kind| kind.value_str()),
             AttrKind::DocComment(..) => None,
         }
     }
 
     pub fn meta_item_list(&self) -> Option<Vec<NestedMetaItem>> {
-        match self.kind {
-            AttrKind::Normal(ref normal) => match normal.item.meta_kind() {
+        match &self.kind {
+            AttrKind::Normal(normal) => match normal.item.meta_kind() {
                 Some(MetaItemKind::List(list)) => Some(list),
                 _ => None,
             },
@@ -191,8 +189,8 @@ impl MetaItem {
     }
 
     pub fn meta_item_list(&self) -> Option<&[NestedMetaItem]> {
-        match self.kind {
-            MetaItemKind::List(ref l) => Some(&l[..]),
+        match &self.kind {
+            MetaItemKind::List(l) => Some(&**l),
             _ => None,
         }
     }
@@ -268,9 +266,9 @@ impl Attribute {
     /// * `#[doc = "doc"]` returns `Some("doc")`.
     /// * `#[doc(...)]` returns `None`.
     pub fn doc_str(&self) -> Option<Symbol> {
-        match self.kind {
-            AttrKind::DocComment(.., data) => Some(data),
-            AttrKind::Normal(ref normal) if normal.item.path == sym::doc => {
+        match &self.kind {
+            AttrKind::DocComment(.., data) => Some(*data),
+            AttrKind::Normal(normal) if normal.item.path == sym::doc => {
                 normal.item.meta_kind().and_then(|kind| kind.value_str())
             }
             _ => None,
@@ -282,8 +280,8 @@ impl Attribute {
     }
 
     pub fn get_normal_item(&self) -> &AttrItem {
-        match self.kind {
-            AttrKind::Normal(ref normal) => &normal.item,
+        match &self.kind {
+            AttrKind::Normal(normal) => &normal.item,
             AttrKind::DocComment(..) => panic!("unexpected doc comment"),
         }
     }
@@ -297,28 +295,28 @@ impl Attribute {
 
     /// Extracts the MetaItem from inside this Attribute.
     pub fn meta(&self) -> Option<MetaItem> {
-        match self.kind {
-            AttrKind::Normal(ref normal) => normal.item.meta(self.span),
+        match &self.kind {
+            AttrKind::Normal(normal) => normal.item.meta(self.span),
             AttrKind::DocComment(..) => None,
         }
     }
 
     pub fn meta_kind(&self) -> Option<MetaItemKind> {
-        match self.kind {
-            AttrKind::Normal(ref normal) => normal.item.meta_kind(),
+        match &self.kind {
+            AttrKind::Normal(normal) => normal.item.meta_kind(),
             AttrKind::DocComment(..) => None,
         }
     }
 
     pub fn tokens(&self) -> TokenStream {
-        match self.kind {
-            AttrKind::Normal(ref normal) => normal
+        match &self.kind {
+            AttrKind::Normal(normal) => normal
                 .tokens
                 .as_ref()
                 .unwrap_or_else(|| panic!("attribute is missing tokens: {:?}", self))
                 .to_attr_token_stream()
                 .to_tokenstream(),
-            AttrKind::DocComment(comment_kind, data) => TokenStream::new(vec![TokenTree::Token(
+            &AttrKind::DocComment(comment_kind, data) => TokenStream::new(vec![TokenTree::Token(
                 Token::new(token::DocComment(comment_kind, self.style, data), self.span),
                 Spacing::Alone,
             )]),
@@ -496,17 +494,17 @@ impl MetaItem {
                 let span = span.with_hi(segments.last().unwrap().ident.span.hi());
                 Path { span, segments, tokens: None }
             }
-            Some(TokenTree::Token(Token { kind: token::Interpolated(nt), .. }, _)) => match *nt {
-                token::Nonterminal::NtMeta(ref item) => return item.meta(item.path.span),
-                token::Nonterminal::NtPath(ref path) => (**path).clone(),
+            Some(TokenTree::Token(Token { kind: token::Interpolated(nt), .. }, _)) => match &*nt {
+                token::Nonterminal::NtMeta(item) => return item.meta(item.path.span),
+                token::Nonterminal::NtPath(path) => (**path).clone(),
                 _ => return None,
             },
             _ => return None,
         };
         let list_closing_paren_pos = tokens.peek().map(|tt| tt.span().hi());
         let kind = MetaItemKind::from_tokens(tokens)?;
-        let hi = match kind {
-            MetaItemKind::NameValue(ref lit) => lit.span.hi(),
+        let hi = match &kind {
+            MetaItemKind::NameValue(lit) => lit.span.hi(),
             MetaItemKind::List(..) => list_closing_paren_pos.unwrap_or(path.span.hi()),
             _ => path.span.hi(),
         };
@@ -518,8 +516,8 @@ impl MetaItem {
 impl MetaItemKind {
     pub fn value_str(&self) -> Option<Symbol> {
         match self {
-            MetaItemKind::NameValue(ref v) => match v.kind {
-                LitKind::Str(ref s, _) => Some(*s),
+            MetaItemKind::NameValue(v) => match v.kind {
+                LitKind::Str(s, _) => Some(s),
                 _ => None,
             },
             _ => None,
@@ -557,15 +555,15 @@ impl MetaItemKind {
     }
 
     fn token_trees(&self, span: Span) -> Vec<TokenTree> {
-        match *self {
+        match self {
             MetaItemKind::Word => vec![],
-            MetaItemKind::NameValue(ref lit) => {
+            MetaItemKind::NameValue(lit) => {
                 vec![
                     TokenTree::token_alone(token::Eq, span),
                     TokenTree::Token(lit.to_token(), Spacing::Alone),
                 ]
             }
-            MetaItemKind::List(ref list) => {
+            MetaItemKind::List(list) => {
                 let mut tokens = Vec::new();
                 for (i, item) in list.iter().enumerate() {
                     if i > 0 {
@@ -648,16 +646,16 @@ impl MetaItemKind {
 
 impl NestedMetaItem {
     pub fn span(&self) -> Span {
-        match *self {
-            NestedMetaItem::MetaItem(ref item) => item.span,
-            NestedMetaItem::Literal(ref lit) => lit.span,
+        match self {
+            NestedMetaItem::MetaItem(item) => item.span,
+            NestedMetaItem::Literal(lit) => lit.span,
         }
     }
 
     fn token_trees(&self) -> Vec<TokenTree> {
-        match *self {
-            NestedMetaItem::MetaItem(ref item) => item.token_trees(),
-            NestedMetaItem::Literal(ref lit) => {
+        match self {
+            NestedMetaItem::MetaItem(item) => item.token_trees(),
+            NestedMetaItem::Literal(lit) => {
                 vec![TokenTree::Token(lit.to_token(), Spacing::Alone)]
             }
         }

compiler/rustc_ast/src/mut_visit.rs

@@ -439,15 +439,15 @@ pub fn noop_visit_constraint<T: MutVisitor>(
 ) {
     vis.visit_id(id);
     vis.visit_ident(ident);
-    if let Some(ref mut gen_args) = gen_args {
+    if let Some(gen_args) = gen_args {
         vis.visit_generic_args(gen_args);
     }
     match kind {
-        AssocConstraintKind::Equality { ref mut term } => match term {
+        AssocConstraintKind::Equality { term } => match term {
             Term::Ty(ty) => vis.visit_ty(ty),
             Term::Const(c) => vis.visit_anon_const(c),
         },
-        AssocConstraintKind::Bound { ref mut bounds } => visit_bounds(bounds, vis),
+        AssocConstraintKind::Bound { bounds } => visit_bounds(bounds, vis),
     }
     vis.visit_span(span);
 }
@@ -880,7 +880,7 @@ pub fn noop_flat_map_generic_param<T: MutVisitor>(
     let GenericParam { id, ident, attrs, bounds, kind, colon_span, is_placeholder: _ } = &mut param;
     vis.visit_id(id);
     vis.visit_ident(ident);
-    if let Some(ref mut colon_span) = colon_span {
+    if let Some(colon_span) = colon_span {
         vis.visit_span(colon_span);
     }
     visit_attrs(attrs, vis);

compiler/rustc_ast/src/token.rs

@@ -601,17 +601,18 @@ impl Token {
 
     /// Returns `true` if the token is an interpolated path.
     fn is_path(&self) -> bool {
-        if let Interpolated(ref nt) = self.kind && let NtPath(..) = **nt {
+        if let Interpolated(nt) = &self.kind && let NtPath(..) = **nt {
             return true;
         }
+
         false
     }
 
     /// Would `maybe_whole_expr` in `parser.rs` return `Ok(..)`?
     /// That is, is this a pre-parsed expression dropped into the token stream
     /// (which happens while parsing the result of macro expansion)?
     pub fn is_whole_expr(&self) -> bool {
-        if let Interpolated(ref nt) = self.kind
+        if let Interpolated(nt) = &self.kind
             && let NtExpr(_) | NtLiteral(_) | NtPath(_) | NtBlock(_) = **nt
         {
             return true;
@@ -622,9 +623,10 @@ impl Token {
 
     // Is the token an interpolated block (`$b:block`)?
     pub fn is_whole_block(&self) -> bool {
-        if let Interpolated(ref nt) = self.kind && let NtBlock(..) = **nt {
+        if let Interpolated(nt) = &self.kind && let NtBlock(..) = **nt {
             return true;
         }
+
         false
     }
 

compiler/rustc_ast/src/util/parser.rs

@@ -377,26 +377,26 @@ pub fn needs_par_as_let_scrutinee(order: i8) -> bool {
 /// parens or other delimiters, e.g., `X { y: 1 }`, `X { y: 1 }.method()`, `foo == X { y: 1 }` and
 /// `X { y: 1 } == foo` all do, but `(X { y: 1 }) == foo` does not.
 pub fn contains_exterior_struct_lit(value: &ast::Expr) -> bool {
-    match value.kind {
+    match &value.kind {
         ast::ExprKind::Struct(..) => true,
 
-        ast::ExprKind::Assign(ref lhs, ref rhs, _)
-        | ast::ExprKind::AssignOp(_, ref lhs, ref rhs)
-        | ast::ExprKind::Binary(_, ref lhs, ref rhs) => {
+        ast::ExprKind::Assign(lhs, rhs, _)
+        | ast::ExprKind::AssignOp(_, lhs, rhs)
+        | ast::ExprKind::Binary(_, lhs, rhs) => {
             // X { y: 1 } + X { y: 2 }
             contains_exterior_struct_lit(&lhs) || contains_exterior_struct_lit(&rhs)
         }
-        ast::ExprKind::Await(ref x)
-        | ast::ExprKind::Unary(_, ref x)
-        | ast::ExprKind::Cast(ref x, _)
-        | ast::ExprKind::Type(ref x, _)
-        | ast::ExprKind::Field(ref x, _)
-        | ast::ExprKind::Index(ref x, _) => {
+        ast::ExprKind::Await(x)
+        | ast::ExprKind::Unary(_, x)
+        | ast::ExprKind::Cast(x, _)
+        | ast::ExprKind::Type(x, _)
+        | ast::ExprKind::Field(x, _)
+        | ast::ExprKind::Index(x, _) => {
             // &X { y: 1 }, X { y: 1 }.y
             contains_exterior_struct_lit(&x)
         }
 
-        ast::ExprKind::MethodCall(box ast::MethodCall { ref receiver, .. }) => {
+        ast::ExprKind::MethodCall(box ast::MethodCall { receiver, .. }) => {
             // X { y: 1 }.bar(...)
             contains_exterior_struct_lit(&receiver)
         }