| 1 | /* |
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| 2 | * Copyright Andrey Semashev 2018. |
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| 3 | * Distributed under the Boost Software License, Version 1.0. |
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| 4 | * (See accompanying file LICENSE_1_0.txt or copy at |
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| 5 | * http://www.boost.org/LICENSE_1_0.txt) |
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| 6 | */ |
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| 7 | /*! |
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| 8 | * \file allocator_traits.hpp |
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| 9 | * \author Andrey Semashev |
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| 10 | * \date 03.01.2018 |
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| 11 | * |
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| 12 | * \brief This header is the Boost.Log library implementation, see the library documentation |
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| 13 | * at http://www.boost.org/doc/libs/release/libs/log/doc/html/index.html. |
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| 14 | */ |
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| 15 | |
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| 16 | #ifndef BOOST_LOG_ALLOCATOR_TRAITS_HPP_INCLUDED_ |
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| 17 | #define BOOST_LOG_ALLOCATOR_TRAITS_HPP_INCLUDED_ |
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| 18 | |
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| 19 | #include <memory> |
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| 20 | #include <boost/log/detail/config.hpp> |
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| 21 | #if defined(BOOST_NO_CXX11_ALLOCATOR) |
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| 22 | #include <boost/core/allocator_access.hpp> |
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| 23 | #include <boost/core/allocator_traits.hpp> |
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| 24 | #endif |
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| 25 | #include <boost/log/utility/use_std_allocator.hpp> |
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| 26 | #include <boost/log/detail/header.hpp> |
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| 27 | |
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| 28 | #ifdef BOOST_HAS_PRAGMA_ONCE |
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| 29 | #pragma once |
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| 30 | #endif |
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| 31 | |
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| 32 | namespace boost { |
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| 33 | |
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| 34 | BOOST_LOG_OPEN_NAMESPACE |
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| 35 | |
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| 36 | namespace aux { |
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| 37 | |
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| 38 | // A portable name for allocator traits |
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| 39 | #if !defined(BOOST_NO_CXX11_ALLOCATOR) |
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| 40 | using std::allocator_traits; |
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| 41 | #else |
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| 42 | using boost::allocator_traits; |
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| 43 | #endif |
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| 44 | |
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| 45 | /*! |
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| 46 | * \brief A standalone trait to rebind an allocator to another type. |
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| 47 | * |
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| 48 | * This trait mostly exists to hide differences between <tt>std::allocator_traits</tt> and <tt>boost::allocator_traits</tt> |
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| 49 | * in terms of allocator rebinding and also provide custom behavior in some cases. |
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| 50 | */ |
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| 51 | template< typename Allocator, typename U > |
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| 52 | struct rebind_alloc |
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| 53 | { |
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| 54 | #if !defined(BOOST_NO_CXX11_ALLOCATOR) |
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| 55 | typedef typename std::allocator_traits< Allocator >::BOOST_NESTED_TEMPLATE rebind_alloc< U > type; |
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| 56 | #else |
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| 57 | typedef typename boost::allocator_rebind< Allocator, U >::type type; |
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| 58 | #endif |
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| 59 | }; |
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| 60 | |
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| 61 | /*! |
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| 62 | * This specialization mostly exists to keep <tt>std::allocator<void></tt> working. |
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| 63 | * The default template will attempt to instantiate the allocator type to test if it provides the nested <tt>rebind</tt> template. |
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| 64 | * We don't want that to happen because it prohibits using <tt>std::allocator<void></tt> in C++17 and later, which deprecated |
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| 65 | * this allocator specialization. This specialization does not use the nested <tt>rebind</tt> template in this case. |
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| 66 | */ |
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| 67 | template< typename T, typename U > |
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| 68 | struct rebind_alloc< std::allocator< T >, U > |
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| 69 | { |
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| 70 | typedef std::allocator< U > type; |
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| 71 | }; |
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| 72 | |
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| 73 | template< typename U > |
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| 74 | struct rebind_alloc< use_std_allocator, U > |
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| 75 | { |
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| 76 | typedef std::allocator< U > type; |
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| 77 | }; |
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| 78 | |
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| 79 | } // namespace aux |
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| 80 | |
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| 81 | BOOST_LOG_CLOSE_NAMESPACE // namespace log |
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| 82 | |
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| 83 | } // namespace boost |
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| 84 | |
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| 85 | #include <boost/log/detail/footer.hpp> |
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| 86 | |
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| 87 | #endif // BOOST_LOG_ALLOCATOR_TRAITS_HPP_INCLUDED_ |
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| 88 | |
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