#include <iostream>
void f( int ) { std::cout << "int, "; }
void f( void * ) { std::cout << "void *, "; }
template< typename T >
void f( T ) { std::cout << "T, "; }

int main() {
    int a; void *b; long c;
    f( a ), f( b ), f( c );
    // outputs: int, void *, T
}