124 lines
		
	
	
		
			3.1 KiB
		
	
	
	
		
			C++
		
	
	
	
		
		
			
		
	
	
			124 lines
		
	
	
		
			3.1 KiB
		
	
	
	
		
			C++
		
	
	
	
|  | //
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|  | // traits/static_require.hpp
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|  | // ~~~~~~~~~~~~~~~~~~~~~~~~~
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|  | //
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|  | // Copyright (c) 2003-2023 Christopher M. Kohlhoff (chris at kohlhoff dot com)
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|  | //
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|  | // Distributed under the Boost Software License, Version 1.0. (See accompanying
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|  | // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
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|  | //
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|  | 
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|  | #ifndef ASIO_TRAITS_STATIC_REQUIRE_HPP
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|  | #define ASIO_TRAITS_STATIC_REQUIRE_HPP
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|  | 
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|  | #if defined(_MSC_VER) && (_MSC_VER >= 1200)
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|  | # pragma once
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|  | #endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
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|  | 
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|  | #include "asio/detail/config.hpp"
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|  | #include "asio/detail/type_traits.hpp"
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|  | #include "asio/traits/static_query.hpp"
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|  | 
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|  | #if defined(ASIO_HAS_DECLTYPE) \
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|  |   && defined(ASIO_HAS_NOEXCEPT) | ||
|  | # define ASIO_HAS_DEDUCED_STATIC_REQUIRE_TRAIT 1
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|  | #endif // defined(ASIO_HAS_DECLTYPE)
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|  |        //   && defined(ASIO_HAS_NOEXCEPT)
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|  | 
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|  | #include "asio/detail/push_options.hpp"
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|  | 
 | ||
|  | namespace asio { | ||
|  | namespace traits { | ||
|  | 
 | ||
|  | template <typename T, typename Property, typename = void> | ||
|  | struct static_require_default; | ||
|  | 
 | ||
|  | template <typename T, typename Property, typename = void> | ||
|  | struct static_require; | ||
|  | 
 | ||
|  | } // namespace traits
 | ||
|  | namespace detail { | ||
|  | 
 | ||
|  | struct no_static_require | ||
|  | { | ||
|  |   ASIO_STATIC_CONSTEXPR(bool, is_valid = false); | ||
|  | }; | ||
|  | 
 | ||
|  | template <typename T, typename Property, typename = void> | ||
|  | struct static_require_trait : | ||
|  |   conditional< | ||
|  |     is_same<T, typename decay<T>::type>::value | ||
|  |       && is_same<Property, typename decay<Property>::type>::value, | ||
|  |     no_static_require, | ||
|  |     traits::static_require< | ||
|  |       typename decay<T>::type, | ||
|  |       typename decay<Property>::type> | ||
|  |   >::type | ||
|  | { | ||
|  | }; | ||
|  | 
 | ||
|  | #if defined(ASIO_HAS_DEDUCED_STATIC_REQUIRE_TRAIT)
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|  | 
 | ||
|  | #if defined(ASIO_HAS_WORKING_EXPRESSION_SFINAE)
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|  | 
 | ||
|  | template <typename T, typename Property> | ||
|  | struct static_require_trait<T, Property, | ||
|  |   typename enable_if< | ||
|  |     decay<Property>::type::value() == traits::static_query<T, Property>::value() | ||
|  |   >::type> | ||
|  | { | ||
|  |   ASIO_STATIC_CONSTEXPR(bool, is_valid = true); | ||
|  | }; | ||
|  | 
 | ||
|  | #else // defined(ASIO_HAS_WORKING_EXPRESSION_SFINAE)
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|  | 
 | ||
|  | false_type static_require_test(...); | ||
|  | 
 | ||
|  | template <typename T, typename Property> | ||
|  | true_type static_require_test(T*, Property*, | ||
|  |     typename enable_if< | ||
|  |       Property::value() == traits::static_query<T, Property>::value() | ||
|  |     >::type* = 0); | ||
|  | 
 | ||
|  | template <typename T, typename Property> | ||
|  | struct has_static_require | ||
|  | { | ||
|  |   ASIO_STATIC_CONSTEXPR(bool, value = | ||
|  |     decltype((static_require_test)( | ||
|  |       static_cast<T*>(0), static_cast<Property*>(0)))::value); | ||
|  | }; | ||
|  | 
 | ||
|  | template <typename T, typename Property> | ||
|  | struct static_require_trait<T, Property, | ||
|  |   typename enable_if< | ||
|  |     has_static_require<typename decay<T>::type, | ||
|  |       typename decay<Property>::type>::value | ||
|  |   >::type> | ||
|  | { | ||
|  |   ASIO_STATIC_CONSTEXPR(bool, is_valid = true); | ||
|  | }; | ||
|  | 
 | ||
|  | #endif // defined(ASIO_HAS_WORKING_EXPRESSION_SFINAE)
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|  | 
 | ||
|  | #endif // defined(ASIO_HAS_DEDUCED_STATIC_REQUIRE_TRAIT)
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|  | 
 | ||
|  | } // namespace detail
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|  | namespace traits { | ||
|  | 
 | ||
|  | template <typename T, typename Property, typename> | ||
|  | struct static_require_default : detail::static_require_trait<T, Property> | ||
|  | { | ||
|  | }; | ||
|  | 
 | ||
|  | template <typename T, typename Property, typename> | ||
|  | struct static_require : static_require_default<T, Property> | ||
|  | { | ||
|  | }; | ||
|  | 
 | ||
|  | } // namespace traits
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|  | } // namespace asio
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|  | 
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|  | #include "asio/detail/pop_options.hpp"
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|  | 
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|  | #endif // ASIO_TRAITS_STATIC_REQUIRE_HPP
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