Given the following code:
给出以下代码:
#include <iostream>
#include <optional>
struct foo
{
explicit operator std::optional<int>() {
return std::optional<int>( 1 );
}
explicit operator int() {
return 0;
}
};
int main()
{
foo my_foo;
std::optional<int> my_opt( my_foo );
std::cout << "value: " << my_opt.value() << std::endl;
}
#include