#include <variant>

#include <string>

#include <iostream>

int main()

{

std::variant<int, std::string> v = "abc";

std::cout << std::boolalpha

<< "variant holds int? "

<< std::holds_alternative<int>(v) << '\n'

<< "variant holds string? "

<< std::holds_alternative<std::string>(v) << '\n';

}