libstdc++
alloc_traits.h
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00001 // Allocator traits -*- C++ -*-
00002 
00003 // Copyright (C) 2011-2015 Free Software Foundation, Inc.
00004 //
00005 // This file is part of the GNU ISO C++ Library.  This library is free
00006 // software; you can redistribute it and/or modify it under the
00007 // terms of the GNU General Public License as published by the
00008 // Free Software Foundation; either version 3, or (at your option)
00009 // any later version.
00010 
00011 // This library is distributed in the hope that it will be useful,
00012 // but WITHOUT ANY WARRANTY; without even the implied warranty of
00013 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00014 // GNU General Public License for more details.
00015 
00016 // Under Section 7 of GPL version 3, you are granted additional
00017 // permissions described in the GCC Runtime Library Exception, version
00018 // 3.1, as published by the Free Software Foundation.
00019 
00020 // You should have received a copy of the GNU General Public License and
00021 // a copy of the GCC Runtime Library Exception along with this program;
00022 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
00023 // <http://www.gnu.org/licenses/>.
00024 
00025 /** @file ext/alloc_traits.h
00026  *  This file is a GNU extension to the Standard C++ Library.
00027  */
00028 
00029 #ifndef _EXT_ALLOC_TRAITS_H
00030 #define _EXT_ALLOC_TRAITS_H 1
00031 
00032 #pragma GCC system_header
00033 
00034 #if __cplusplus >= 201103L
00035 # include <bits/move.h>
00036 # include <bits/alloc_traits.h>
00037 #else
00038 # include <bits/allocator.h>  // for __alloc_swap
00039 #endif
00040 
00041 namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
00042 {
00043 _GLIBCXX_BEGIN_NAMESPACE_VERSION
00044 
00045 #if __cplusplus >= 201103L
00046   template<typename _Alloc>
00047     struct __allocator_always_compares_equal : std::false_type { };
00048 
00049   template<typename _Tp>
00050     struct __allocator_always_compares_equal<std::allocator<_Tp>>
00051     : std::true_type { };
00052 
00053   template<typename, typename> struct array_allocator;
00054 
00055   template<typename _Tp, typename _Array>
00056     struct __allocator_always_compares_equal<array_allocator<_Tp, _Array>>
00057     : std::true_type { };
00058 
00059   template<typename> struct bitmap_allocator;
00060 
00061   template<typename _Tp>
00062     struct __allocator_always_compares_equal<bitmap_allocator<_Tp>>
00063     : std::true_type { };
00064 
00065   template<typename> struct malloc_allocator;
00066 
00067   template<typename _Tp>
00068     struct __allocator_always_compares_equal<malloc_allocator<_Tp>>
00069     : std::true_type { };
00070 
00071   template<typename> struct mt_allocator;
00072 
00073   template<typename _Tp>
00074     struct __allocator_always_compares_equal<mt_allocator<_Tp>>
00075     : std::true_type { };
00076 
00077   template<typename> struct new_allocator;
00078 
00079   template<typename _Tp>
00080     struct __allocator_always_compares_equal<new_allocator<_Tp>>
00081     : std::true_type { };
00082 
00083   template<typename> struct pool_allocator;
00084 
00085   template<typename _Tp>
00086     struct __allocator_always_compares_equal<pool_allocator<_Tp>>
00087     : std::true_type { };
00088 #endif
00089 
00090 /**
00091  * @brief  Uniform interface to C++98 and C++0x allocators.
00092  * @ingroup allocators
00093 */
00094 template<typename _Alloc>
00095   struct __alloc_traits
00096 #if __cplusplus >= 201103L
00097   : std::allocator_traits<_Alloc>
00098 #endif
00099   {
00100     typedef _Alloc allocator_type;
00101 #if __cplusplus >= 201103L
00102     typedef std::allocator_traits<_Alloc>           _Base_type;
00103     typedef typename _Base_type::value_type         value_type;
00104     typedef typename _Base_type::pointer            pointer;
00105     typedef typename _Base_type::const_pointer      const_pointer;
00106     typedef typename _Base_type::size_type          size_type;
00107     typedef typename _Base_type::difference_type    difference_type;
00108     // C++11 allocators do not define reference or const_reference
00109     typedef value_type&                             reference;
00110     typedef const value_type&                       const_reference;
00111     using _Base_type::allocate;
00112     using _Base_type::deallocate;
00113     using _Base_type::construct;
00114     using _Base_type::destroy;
00115     using _Base_type::max_size;
00116 
00117   private:
00118     template<typename _Ptr>
00119       using __is_custom_pointer
00120         = std::__and_<std::is_same<pointer, _Ptr>,
00121                       std::__not_<std::is_pointer<_Ptr>>>;
00122 
00123   public:
00124     // overload construct for non-standard pointer types
00125     template<typename _Ptr, typename... _Args>
00126       static typename std::enable_if<__is_custom_pointer<_Ptr>::value>::type
00127       construct(_Alloc& __a, _Ptr __p, _Args&&... __args)
00128       {
00129         _Base_type::construct(__a, std::addressof(*__p),
00130                               std::forward<_Args>(__args)...);
00131       }
00132 
00133     // overload destroy for non-standard pointer types
00134     template<typename _Ptr>
00135       static typename std::enable_if<__is_custom_pointer<_Ptr>::value>::type
00136       destroy(_Alloc& __a, _Ptr __p)
00137       { _Base_type::destroy(__a, std::addressof(*__p)); }
00138 
00139     static _Alloc _S_select_on_copy(const _Alloc& __a)
00140     { return _Base_type::select_on_container_copy_construction(__a); }
00141 
00142     static void _S_on_swap(_Alloc& __a, _Alloc& __b)
00143     { std::__alloc_on_swap(__a, __b); }
00144 
00145     static constexpr bool _S_propagate_on_copy_assign()
00146     { return _Base_type::propagate_on_container_copy_assignment::value; }
00147 
00148     static constexpr bool _S_propagate_on_move_assign()
00149     { return _Base_type::propagate_on_container_move_assignment::value; }
00150 
00151     static constexpr bool _S_propagate_on_swap()
00152     { return _Base_type::propagate_on_container_swap::value; }
00153 
00154     static constexpr bool _S_always_equal()
00155     { return __allocator_always_compares_equal<_Alloc>::value; }
00156 
00157     static constexpr bool _S_nothrow_move()
00158     { return _S_propagate_on_move_assign() || _S_always_equal(); }
00159 
00160     static constexpr bool _S_nothrow_swap()
00161     {
00162       using std::swap;
00163       return !_S_propagate_on_swap()
00164         || noexcept(swap(std::declval<_Alloc&>(), std::declval<_Alloc&>()));
00165     }
00166 
00167     template<typename _Tp>
00168       struct rebind
00169       { typedef typename _Base_type::template rebind_alloc<_Tp> other; };
00170 #else
00171 
00172     typedef typename _Alloc::pointer                pointer;
00173     typedef typename _Alloc::const_pointer          const_pointer;
00174     typedef typename _Alloc::value_type             value_type;
00175     typedef typename _Alloc::reference              reference;
00176     typedef typename _Alloc::const_reference        const_reference;
00177     typedef typename _Alloc::size_type              size_type;
00178     typedef typename _Alloc::difference_type        difference_type;
00179 
00180     static pointer
00181     allocate(_Alloc& __a, size_type __n)
00182     { return __a.allocate(__n); }
00183 
00184     static void deallocate(_Alloc& __a, pointer __p, size_type __n)
00185     { __a.deallocate(__p, __n); }
00186 
00187     template<typename _Tp>
00188       static void construct(_Alloc& __a, pointer __p, const _Tp& __arg)
00189       { __a.construct(__p, __arg); }
00190 
00191     static void destroy(_Alloc& __a, pointer __p)
00192     { __a.destroy(__p); }
00193 
00194     static size_type max_size(const _Alloc& __a)
00195     { return __a.max_size(); }
00196 
00197     static const _Alloc& _S_select_on_copy(const _Alloc& __a) { return __a; }
00198 
00199     static void _S_on_swap(_Alloc& __a, _Alloc& __b)
00200     {
00201       // _GLIBCXX_RESOLVE_LIB_DEFECTS
00202       // 431. Swapping containers with unequal allocators.
00203       std::__alloc_swap<_Alloc>::_S_do_it(__a, __b);
00204     }
00205 
00206     template<typename _Tp>
00207       struct rebind
00208       { typedef typename _Alloc::template rebind<_Tp>::other other; };
00209 #endif
00210   };
00211 
00212 _GLIBCXX_END_NAMESPACE_VERSION
00213 } // namespace __gnu_cxx
00214 
00215 #endif