#include <limits>

class Foo {
public:
    constexpr Foo(const int value) : value(value) {}    
    constexpr operator int () const { return value; }
    
private:
    int value;
};

class Bar : public Foo {
public:
	using Foo::Foo;
    constexpr static Foo UNKNOWN = std::numeric_limits<int>::max();
    constexpr static Foo ANY     = UNKNOWN - 1;
};

int main() {
	return Bar(0);
}