Returning pointer-to-member-function (without typedefs)

Question

Compiling on C++03, I've attempted to write up a test template function that returns a pointer-to-member-function of a member function that returns int, and takes two float arguments:

template<typename TemplateClass>
int (TemplateClass::*)(float,float) Testtest(TemplateClass &A)
{
    return &TemplateClass::Function;
}

But naturally, no matter what variations on the pointer-to-member-function syntax I use, the compiler complains of initialisation errors. Typedef, although it works with known classes, for obvious reasons (naming conflicts), won't accept template class arguments for classes that I can't know ahead of time which are likely to use the same function.

What non-typedef way is there to get this function to compile and return a pointer-to-member-function?

Answer 1

To declare it without a type alias, without type deduction, and without a trailing return type:

template<typename TemplateClass>
int (TemplateClass::* Testtest(TemplateClass &A))(float,float)

But of course this isn't what you would use in real code. Instead you would use an alias template:

template<typename T>
using return_type = int (T::*)(float,float);

template<typename TemplateClass>
return_type<TemplateClass> Testtest(TemplateClass &A)

Or return type deduction in C++14:

template<typename TemplateClass>
auto Testtest(TemplateClass &A)

Or a trailing return type (in C++11):

template<typename TemplateClass>
auto Testtest(TemplateClass &A) -> int (TemplateClass::*)(float,float)

Answer 2

You need this prototype:

template<typename TemplateClass>
int (TemplateClass::*Testtest(TemplateClass &A)) (float,float) { }