Overriding return type in function template specialization

Question

I would like to specialize a function template such that the return type changes depending on the type of the template argument.

class ReturnTypeSpecializati         


        

Answer 1

Since the specialization has to agree with the base template on the return type, you can make it so by adding a "return type trait", a struct you can specialize and draw the true return type from:

// in the normal case, just the identity
template
struct item_return{ typedef T type; };

template
typename item_return::type item();

template<>
struct item_return{ typedef int type; };
template<>
int item();

Live example.

Note that you might want to stick to the following, so you only need to update the return-type in the item_return specialization.

template<>
item_return::type foo(){ ... }
// note: No `typename` needed, because `float` is not a dependent type