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/// \brief The free-function template,
/// which is overloading a method with the same name in AbstractA below.
template <class T>
inline const T overloadedMethod(const T& lhs, const T& rhs)
{
    return T(lhs.value+rhs.value);
}
 
/// \brief AbstractA class
class AbstractA
{
public:
    AbstractA (int aVal):
      value(aVal)
      {}
 
 
      inline const AbstractA overloadedMethod(const AbstractA &rhs) const
      {
          return AbstractA(value+rhs.value);            
      }
 
protected:
    int value;
};
 
/// \brief A class, deriving from AbstractA,
/// and friending the free-function template.
class A : public AbstractA
{   
    friend const A overloadedMethod <A>(const A& lhs, const A& rhs);
        /// This one gives me compilation error
    //template<class T> friend const T overloadedMethod(const T& lhs, const T& rhs);
        /// This one would be okay
 
public:
    A (int aVal):
      AbstractA(aVal)
      {}
};
 
int main()
{
   A a1(1), a2(2);
   overloadedMethod(a1, a2);
 
   return 0;
}

prog.cpp:31:20: error: field ‘overloadedMethod’ has incomplete type
     friend const A overloadedMethod <A>(const A& lhs, const A& rhs);
                    ^
prog.cpp:31:20: error: expected ‘;’ at end of member declaration
prog.cpp:31:37: error: expected unqualified-id before ‘<’ token
     friend const A overloadedMethod <A>(const A& lhs, const A& rhs);
                                     ^
prog.cpp: In instantiation of ‘const T overloadedMethod(const T&, const T&) [with T = A]’:
prog.cpp:45:27:   required from here
prog.cpp:24:9: error: ‘int AbstractA::value’ is protected
     int value;
         ^
prog.cpp:6:23: error: within this context
     return T(lhs.value+rhs.value);
                       ^
prog.cpp:24:9: error: ‘int AbstractA::value’ is protected
     int value;
         ^
prog.cpp:6:23: error: within this context
     return T(lhs.value+rhs.value);
                       ^

Standard output is empty