typeChecks.hpp

#pragma once
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wnonnull"
 
#include <type_traits>
 
namespace z ::core::types {
struct no {};
 
template <typename T, typename Arg>
no operator<(const T &, const Arg &);
template <typename T, typename Arg>
no operator>(const T &, const Arg &);
template <typename T, typename Arg>
no operator==(const T &, const Arg &);
 
template <typename T, typename Arg = T>
struct lesserExists {
    enum { value = !std::is_same<decltype(std::declval<T>() < std::declval<Arg>()), no>::value };
};
 
template <typename T, typename Arg = T>
struct greaterExists {
    enum { value = !std::is_same<decltype(std::declval<T>() > std::declval<Arg>()), no>::value };
};
 
template <typename T, typename Arg = T>
struct equalExists {
    enum { value = !std::is_same<decltype(std::declval<T>() == std::declval<Arg>()), no>::value };
};
 
} // namespace z::core::types
 
#pragma GCC diagnostic pop