#include <iostream>

#include <type_traits>

class A {};

class B : A {};

class C {};

int main()

{

std::cout << std::boolalpha;

std::cout << "a2b: " << std::is_base_of<A, B>::value << '\n';

std::cout << "b2a: " << std::is_base_of<B, A>::value << '\n';

std::cout << "c2b: " << std::is_base_of<C, B>::value << '\n';

std::cout << "same type: " << std::is_base_of<C, C>::value << '\n';

}