is_assignable_from.hpp

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//
//  CeresEngine - A game development framework
//
//  Created by Rogiel Sulzbach.
//  Copyright (c) 2018-2022 Rogiel Sulzbach. All rights reserved.
//
 
#pragma once
 
#include "CeresEngine/Foundation/Traits/is_constructible_from.hpp"
#include "CeresEngine/Foundation/Traits/is_convertible_to.hpp"
 
#include <type_traits>
 
namespace CeresEngine::traits {
 
    template<class LHS, class RHS, class = void> struct is_assignable_from : std::false_type {};
 
    template<class LHS, class RHS>
    struct is_assignable_from<LHS, RHS,
        std::enable_if_t<
            // clang-format off
            std::is_lvalue_reference_v<LHS> &&
            std::is_same_v<decltype(std::declval<LHS>() = std::declval<RHS&&>()), LHS>
            // clang-format on
            >> : std::true_type {};
 
    template<class LHS, class RHS> bool constexpr is_assignable_from_v = is_assignable_from<LHS, RHS>::value;
 
    template<class LHS, class RHS>
    concept assignable_from = is_assignable_from_v<LHS, RHS>;
 
} // namespace CeresEngine::traits