Merge pull request #1738 from drdanz/const_sinkhole

Improve const correctness

bindings/yarp.i

@@ -146,7 +146,7 @@
 #ifdef SWIGJAVA
     %rename(wait_c) *::wait();
     %rename(clone_c) *::clone() const;
-    %rename(toString_c) *::toString();
+    %rename(toString_c) *::toString() const;
 #endif
 
 #ifdef SWIGCHICKEN

doc/release/v3_0_0.md

@@ -108,6 +108,11 @@ Important Changes
   Note that `RateThread` used the period in msec(int), `PeriodicThread`
   requires the period in sec(double), so remember to consider a x1000 factor
   when migrate the code.
+* Several methods in public interfaces have a slightly different signature (see
+  #1738 for details).
+* It is now possible to write a `const Portable` on a `Port`.
+* `const Bytes` and `const ManagedBytes` can no longer return non-const pointers
+  to the underlying data.
 
 #### `YARP_dev`
 
@@ -182,6 +187,8 @@ Important Changes
   `IPositionDirect::setPositions(const int, const int*, const double*)`(#1351).
 * The file `yarp/dev/ControlBoardInterfacesImpl.inl` was renamed
   `yarp/dev/ControlBoardInterfacesImpl-inl.h`
+* Several methods in public interfaces have a slightly different signature (see
+  #1738 for details).
 
 #### `YARP_sig`
 

example/carrier/carrier_human.cpp

@@ -60,7 +60,7 @@ class HumanStream : public yarp::os::TwoWayStream, public yarp::os::InputStream,
     /////////////////////////////////////////////////
     // InputStream
 
-    virtual ssize_t read(const yarp::os::Bytes& b) {
+    virtual ssize_t read(yarp::os::Bytes& b) {
         if (interrupting) { return -1; }
         while (inputCache.size() < b.length()) {
             yInfo() <<"*** CHECK OTHER TERMINAL FOR SOMETHING TO TYPE:";
@@ -144,48 +144,48 @@ class HumanCarrier : public yarp::os::Carrier {
     /////////////////////////////////////////////////
     // First, the easy bits...
 
-    virtual yarp::os::Carrier *create() {
+    virtual yarp::os::Carrier *create() const {
         return new HumanCarrier();
     }
 
-    virtual std::string getName() {
+    virtual std::string getName() const {
         return "human";
     }
 
-    virtual bool isConnectionless() {
+    virtual bool isConnectionless() const {
         return true;
     }
 
-    virtual bool canAccept() {
+    virtual bool canAccept() const {
         return true;
     }
 
-    virtual bool canOffer() {
+    virtual bool canOffer() const {
         return true;
     }
 
-    virtual bool isTextMode() {
+    virtual bool isTextMode() const {
         // let's be text mode, for human-friendliness
         return true;
     }
 
-    virtual bool canEscape() {
+    virtual bool canEscape() const {
         return true;
     }
 
-    virtual bool requireAck() {
+    virtual bool requireAck() const {
         return true;
     }
 
-    virtual bool supportReply() {
+    virtual bool supportReply() const {
         return true;
     }
 
-    virtual bool isLocal() {
+    virtual bool isLocal() const {
         return false;
     }
 
-    virtual std::string toString() {
+    virtual std::string toString() const {
         return "humans are handy";
     }
 

example/carrier/carrier_stub.cpp

@@ -21,23 +21,28 @@
  * 8-bytes of a regular text mode connection.
  *
  */
-class TestCarrier : public yarp::os::impl::TextCarrier {
-
+class TestCarrier : public yarp::os::impl::TextCarrier
+{
+
 public:
-    virtual std::string getName() {
+    virtual std::string getName() const override
+    {
         return "test";
     }
 
-    virtual std::string getSpecifierName() {
+    virtual std::string getSpecifierName() const override
+    {
         return "TESTTEST";
     }
 
-    virtual Carrier *create() {
+    virtual Carrier *create() const override
+    {
         return new TestCarrier();
     }
 };
 
-int main(int argc, char *argv[]) {
+int main(int argc, char *argv[])
+{
     yarp::os::Network yarp;
     yarp::os::Carriers::addCarrierPrototype(new TestCarrier);
 

example/idl/thrift/generated/include/firstInterface/PointQuality.h

@@ -22,7 +22,7 @@ namespace yarp {
 class yarp::test::PointQualityVocab : public yarp::os::idl::WireVocab {
 public:
   virtual int fromString(const std::string& input);
-  virtual std::string toString(int input);
+  virtual std::string toString(int input) const;
 };
 
 

example/os/playback.cpp

@@ -59,7 +59,7 @@ class Saver : public Portable {
         return reader.expectBlock(mem.get(),mem.length());
     }
 
-    virtual bool write(ConnectionWriter& writer) {
+    virtual bool write(ConnectionWriter& writer) const {
         if (mem.length()==0) {
             fprintf(stderr,"Nothing to write.\n");
             return false;

src/carriers/bayer_carrier/BayerCarrier.cpp

@@ -97,7 +97,7 @@ yarp::os::ConnectionReader& BayerCarrier::modifyIncomingData(yarp::os::Connectio
     have_result = false;
     if (need_reset) {
         int m = DC1394_BAYER_METHOD_BILINEAR;
-        Searchable& config = reader.getConnectionModifiers();
+        const Searchable& config = reader.getConnectionModifiers();
         half = false;
         if (config.check("size")) {
             if (config.find("size").asString() == "half") {
@@ -293,6 +293,10 @@ bool BayerCarrier::debayerFull(yarp::sig::ImageOf<PixelMono>& src,
     return true;
 }
 
+bool BayerCarrier::processBuffered() const {
+    return const_cast<BayerCarrier*>(this)->processBuffered();
+}
+
 bool BayerCarrier::processBuffered() {
     if (!have_result) {
         //printf("Copy-based conversion.\n");
@@ -310,7 +314,7 @@ bool BayerCarrier::processBuffered() {
     return true;
 }
 
-bool BayerCarrier::processDirect(const yarp::os::Bytes& bytes) {
+bool BayerCarrier::processDirect(yarp::os::Bytes& bytes) {
     if (have_result) {
         memcpy(bytes.get(),out.getRawImage(),bytes.length());
         return true;
@@ -328,7 +332,7 @@ bool BayerCarrier::processDirect(const yarp::os::Bytes& bytes) {
 }
 
 
-yarp::conf::ssize_t BayerCarrier::read(const yarp::os::Bytes& b) {
+yarp::conf::ssize_t BayerCarrier::read(yarp::os::Bytes& b) {
     // copy across small stuff - the image header
     if (consumed<sizeof(header)) {
         size_t len = b.length();

src/carriers/bayer_carrier/BayerCarrier.h

@@ -87,15 +87,15 @@ class yarp::os::BayerCarrier : public yarp::os::ModifyingCarrier,
         if (local) delete local;
     }
 
-    virtual Carrier *create() override {
+    virtual Carrier *create() const override {
         return new BayerCarrier();
     }
 
-    virtual std::string getName() override {
+    virtual std::string getName() const override {
         return "bayer";
     }
 
-    virtual std::string toString() override {
+    virtual std::string toString() const override {
         return "bayer_carrier";
     }
 
@@ -105,7 +105,7 @@ class yarp::os::BayerCarrier : public yarp::os::ModifyingCarrier,
     ////////////////////////////////////////////////////////////////////////
     // ConnectionReader methods
 
-    virtual bool expectBlock(const char *data, size_t len) override {
+    virtual bool expectBlock(char *data, size_t len) override {
         return local->expectBlock(data,len);
     }
 
@@ -141,19 +141,19 @@ class yarp::os::BayerCarrier : public yarp::os::ModifyingCarrier,
         return local->expectFloat64();
     }
 
-    virtual bool isTextMode() override {
+    virtual bool isTextMode() const override {
         return false;
     }
 
-    virtual bool isBareMode() override {
+    virtual bool isBareMode() const override {
         return false;
     }
 
     virtual bool convertTextMode() override {
         return true;
     }
 
-    virtual size_t getSize() override {
+    virtual size_t getSize() const override {
         if (image_data_len) {
             processBuffered();
         }
@@ -168,35 +168,35 @@ class yarp::os::BayerCarrier : public yarp::os::ModifyingCarrier,
         return parent->readEnvelope();
     }
 
-    virtual Portable *getReference() override {
+    virtual Portable *getReference() const override {
         return parent->getReference();
     }
 
-    virtual Contact getRemoteContact() override {
+    virtual Contact getRemoteContact() const override {
         return parent->getRemoteContact();
     }
 
-    virtual Contact getLocalContact() override {
+    virtual Contact getLocalContact() const override {
         return parent->getLocalContact();
     }
 
-    virtual bool isValid() override {
+    virtual bool isValid() const override {
         return true;
     }
 
-    virtual bool isActive() override {
+    virtual bool isActive() const override {
         return parent->isActive();
     }
 
-    virtual bool isError() override {
+    virtual bool isError() const override {
         return parent->isError()||!happy;
     }
 
     virtual void requestDrop() override {
         parent->requestDrop();
     }
 
-    virtual yarp::os::Searchable& getConnectionModifiers() override {
+    virtual const yarp::os::Searchable& getConnectionModifiers() const override {
         return parent->getConnectionModifiers();
     }
 
@@ -208,12 +208,12 @@ class yarp::os::BayerCarrier : public yarp::os::ModifyingCarrier,
     // InputStream methods
 
     using yarp::os::InputStream::read;
-    virtual yarp::conf::ssize_t read(const yarp::os::Bytes& b) override;
+    virtual yarp::conf::ssize_t read(yarp::os::Bytes& b) override;
 
     virtual void close() override {
     }
 
-    virtual bool isOk() override {
+    virtual bool isOk() const override {
         return happy;
     }
 
@@ -230,9 +230,17 @@ class yarp::os::BayerCarrier : public yarp::os::ModifyingCarrier,
     virtual bool debayerHalf(yarp::sig::ImageOf<yarp::sig::PixelMono>& src,
                              yarp::sig::ImageOf<yarp::sig::PixelRgb>& dest);
 
+    /*
+     * The const version of the processBuffered() method performs a const_cast,
+     * and calls the non-const version. This allows to call it in const methods.
+     * Conceptually this is not completely wrong because it does not modify
+     * the external state of the class, but just some internal representation.
+     */
+    virtual bool processBuffered() const;
+
     virtual bool processBuffered();
 
-    virtual bool processDirect(const yarp::os::Bytes& bytes);
+    virtual bool processDirect(yarp::os::Bytes& bytes);
 
 };