std:: holds_alternative

Checks if the variant v holds the alternative T . The call is ill-formed if T does not appear exactly once in Types...

Parameters

Return value

true if the variant currently holds the alternative T , false otherwise.

Example

#include <cassert>
#include <string>
#include <variant>
 
int main()
{
    std::variant<int, std::string> v = "abc";
    assert(not std::holds_alternative<int>(v));
    assert(std::holds_alternative<std::string>(v));
}

See also