template_utils.h

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// =====================================================================================================================
// Copyright 2024 Medusa Slockbower
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//  http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// =====================================================================================================================
 
#ifndef TEMPLATEUTILS_H
#define TEMPLATEUTILS_H
 
namespace open_cpp_utils
{
 
template<typename T, T V>
struct constant_value
{
    using type = T;
    static constexpr type value = V;
 
    constexpr operator type() const noexcept { return value; }
    [[nodiscard]] constexpr type operator()() const { return value; }
};
 
template<bool V>
using bool_constant = constant_value<bool, V>;
 
using true_type  = bool_constant<true>; 
using false_type = bool_constant<false>; 
 
template<typename, typename>
inline static constexpr bool is_same = false_type{};
 
template<typename T>
inline static constexpr bool is_same<T, T> = true_type{};
 
template<typename...Ts>
inline static constexpr bool is_unique = true_type{};
 
template<typename T, typename...Ts>
inline constexpr bool is_unique<T, Ts...> = bool_constant<(!is_same<T, Ts> && ...) && is_unique<Ts...>>{};
 
}
 
#endif //TEMPLATEUTILS_H