#include <type_traits>
#include <iostream>
#include <string>



template<class T, class Enable = void>
struct A {
    static void f(){
        std::cout << "Global" << std::endl;
    }
};
template<class T>
struct A<T, void> {
    static void f(){
        std::cout << "Specialization void" << std::endl;
    }
};
template<class T>
struct A<T, int> {
    static void f(){
        std::cout << "Specialization int" << std::endl;
    }
};
template<typename T>
void f(T val){
    A<T>::f();
}

int main()
{
    f(0);
    f('ch');
}