type_identity.hpp

/*
 * Copyright (c) 2024 The RefValue Project
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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 * THE SOFTWARE.
 */
 
#pragma once
 
#if __has_include(<version>)
#include <version>
#endif
 
#if __cpp_lib_type_identity >= 201806L
#include <type_traits>
#endif
 
namespace essence {
#if __cpp_lib_type_identity >= 201806L
    using std::type_identity;
    using std::type_identity_t;
#else
    template <typename T>
    struct type_identity {
        using type = T;
    };
 
    template <typename T>
    using type_identity_t = typename type_identity<T>::type;
#endif
} // namespace essence