#pragma once
#include <type_traits>
namespace WTF {
template<typename> struct EnumTraits;
template<typename E, E...> struct EnumValues;
template<typename T, typename E> struct EnumValueChecker;
template<typename T, typename E, E e, E... es>
struct EnumValueChecker<T, EnumValues<E, e, es...>> {
static constexpr bool isValidEnum(T t)
{
return (static_cast<T>(e) == t) ? true : EnumValueChecker<T, EnumValues<E, es...>>::isValidEnum(t);
}
};
template<typename T, typename E>
struct EnumValueChecker<T, EnumValues<E>> {
static constexpr bool isValidEnum(T)
{
return false;
}
};
template<typename E, typename T, typename = std::enable_if_t<!std::is_same_v<std::underlying_type_t<E>, bool>>>
constexpr auto isValidEnum(T t) -> decltype(EnumValueChecker<T, typename EnumTraits<E>::values>::isValidEnum(t), bool())
{
static_assert(sizeof(T) >= sizeof(std::underlying_type_t<E>), "Integral type must be at least the size of the underlying enum type");
return EnumValueChecker<T, typename EnumTraits<E>::values>::isValidEnum(t);
}
template<typename E, typename T, typename = std::enable_if_t<!std::is_same_v<std::underlying_type_t<E>, bool>>>
auto isValidEnum(T t) -> decltype(EnumTraits<E>::isValidEnum(t), bool())
{
return EnumTraits<E>::isValidEnum(t);
}
template<typename E, typename T, typename = std::enable_if_t<std::is_same_v<std::underlying_type_t<E>, bool>>>
constexpr bool isValidEnum(T t)
{
return !t || t == 1;
}
template<typename E>
constexpr auto enumToUnderlyingType(E e)
{
return static_cast<std::underlying_type_t<E>>(e);
}
}
using WTF::isValidEnum;