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TL/include/tl/identifier.h
jeanlemotan 8297b0b45f First
2024-07-02 18:06:33 +02:00

55 lines
1.7 KiB
C++

#pragma once
#include "tl/detail/prologue.h"
#include "tl/hash_map.h"
#include <compare>
namespace tl
{
template<typename T, T invalid_value, typename Tag>
struct identifier
{
using underlying_type = T;
constexpr identifier() noexcept = default;
explicit constexpr identifier(T value) noexcept : m_value(std::move(value)) {}
constexpr T value() const noexcept { return m_value; }
constexpr bool is_valid() const noexcept { return m_value != invalid_value; }
//inline static identifier<T, invalid_value, Tag> invalid() noexcept { return identifier<T, invalid_value, Tag>(); }
auto operator<=>(const identifier<T, invalid_value, Tag>& other) const noexcept { return m_value <=> other.value(); }
auto operator<=>(const T& other) const noexcept { return m_value <=> other; }
bool operator==(const identifier<T, invalid_value, Tag>& other) const noexcept { return m_value == other.value(); }
bool operator==(const T& other) const noexcept { return m_value == other; }
private:
T m_value = invalid_value;
};
}
#define TL_DECLARE_INTEGRAL_ID(NAME, TYPE, INVALID_VALUE) \
struct NAME##_tag {};\
using NAME = tl::identifier<TYPE, INVALID_VALUE, NAME##_tag>;
template <typename T, T invalid_value, typename Tag>
struct std::formatter<tl::identifier<T, invalid_value, Tag>>
{
constexpr auto parse(format_parse_context& ctx) noexcept { return ctx.begin(); }
auto format(const tl::identifier<T, invalid_value, Tag>& id, std::format_context& ctx) const
{
return format_to(ctx.out(), "{}", id.value());
}
};
template<typename T, T invalid_value, typename Tag>
struct eastl::hash<tl::identifier<T, invalid_value, Tag>>
{
size_t operator()(tl::identifier<T, invalid_value, Tag> const& id) const
{
return hash<T>()(id.value());
}
};