Is it possible to overload a function that can tell a fixed array from a pointer?

Question

Motivation:

Almost for fun, I am trying to write a function overload that can tell apart whether the argument is a fixed-size array or a pointer.

Answer 1

You may use the following:

namespace detail
{
    template  struct helper;

    template  struct helper { void operator() () const {std::cout << "pointer\n";} };
    template  struct helper { void operator() ()const {std::cout << "array\n";} };
}


template 
void f(const T& )
{
    detail::helper{}();
}

Live example