GCC 4.4 compatibility: worked around "Sorry, not implemented" error.

New function declaration syntax for deduced return types doesn't work
here fully yet.

src/MeshTools/CompressIndices.h

@@ -38,7 +38,11 @@ class CompressIndices {
         CompressIndices(const std::vector<unsigned int>& indices): indices(indices) {}
 
         inline std::tuple<size_t, Type, char*> operator()() const {
+            #ifndef MAGNUM_GCC44_COMPATIBILITY
             return SizeBasedCall<Compressor>(*std::max_element(indices.begin(), indices.end()))(indices);
+            #else
+            return SizeBasedCall<std::tuple<size_t, Type, char*>, Compressor>(*std::max_element(indices.begin(), indices.end()))(indices);
+            #endif
         }
 
         void operator()(IndexedMesh* mesh, Buffer::Usage usage) const {

src/SizeTraits.h

@@ -101,7 +101,11 @@ based on data size:
 bar = SizeBasedCall<Foo>(dataSize)(arg1, arg2, ...);
 @endcode
 */
+#ifndef MAGNUM_GCC44_COMPATIBILITY
 template<class Base> struct SizeBasedCall: public Base {
+#else
+template<class Return, class Base> struct SizeBasedCall: public Base {
+#endif
     /**
      * @brief Constructor
      * @param size          Data size
@@ -120,7 +124,11 @@ template<class Base> struct SizeBasedCall: public Base {
     #ifndef MAGNUM_GCC45_COMPATIBILITY
     template<typename ...Args> auto operator()(Args&&... arguments) -> decltype(Base::template run<GLubyte>(std::forward<Args>(arguments)...)) {
     #else
+    #ifdef MAGNUM_GCC44_COMPATIBILITY
+    template<typename Args> Return operator()(Args&& arguments) {
+    #else
     template<typename Args> auto operator()(Args&& arguments) -> decltype(Base::template run<GLubyte>(std::forward<Args>(arguments))) {
+    #endif
     #endif
         switch(Math::log(256, size)) {
             case 0:
@@ -148,8 +156,12 @@ template<class Base> struct SizeBasedCall: public Base {
         #ifndef MAGNUM_GCC45_COMPATIBILITY
         return decltype(Base::template run<GLubyte>(std::forward<Args>(arguments)...))();
         #else
+        #ifdef MAGNUM_GCC44_COMPATIBILITY
+        return Return();
+        #else
         return decltype(Base::template run<GLubyte>(std::forward<Args>(arguments)))();
         #endif
+        #endif
     }
 
     private: