libstdc++
array_allocator.h
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00001 // array allocator -*- C++ -*-
00002 
00003 // Copyright (C) 2004-2015 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/array_allocator.h
00026  *  This file is a GNU extension to the Standard C++ Library.
00027  */
00028 
00029 #ifndef _ARRAY_ALLOCATOR_H
00030 #define _ARRAY_ALLOCATOR_H 1
00031 
00032 #include <bits/c++config.h>
00033 #include <new>
00034 #include <bits/functexcept.h>
00035 #include <tr1/array>
00036 #include <bits/move.h>
00037 #if __cplusplus >= 201103L
00038 #include <type_traits>
00039 #endif
00040 
00041 // Suppress deprecated warning for this file.
00042 #pragma GCC diagnostic push
00043 #pragma GCC diagnostic ignored "-Wdeprecated-declarations"
00044 
00045 namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
00046 {
00047 _GLIBCXX_BEGIN_NAMESPACE_VERSION
00048 
00049  using std::size_t;
00050  using std::ptrdiff_t;
00051 
00052   /// Base class.
00053  template<typename _Tp>
00054     class array_allocator_base
00055     {
00056     public:
00057       typedef size_t            size_type;
00058       typedef ptrdiff_t         difference_type;
00059       typedef _Tp*              pointer;
00060       typedef const _Tp*        const_pointer;
00061       typedef _Tp&              reference;
00062       typedef const _Tp&        const_reference;
00063       typedef _Tp               value_type;
00064 
00065       pointer
00066       address(reference __x) const _GLIBCXX_NOEXCEPT
00067       { return std::__addressof(__x); }
00068 
00069       const_pointer
00070       address(const_reference __x) const _GLIBCXX_NOEXCEPT
00071       { return std::__addressof(__x); }
00072 
00073       void
00074       deallocate(pointer, size_type)
00075       { 
00076         // Does nothing.
00077       }
00078 
00079       size_type
00080       max_size() const _GLIBCXX_USE_NOEXCEPT 
00081       { return size_t(-1) / sizeof(_Tp); }
00082 
00083 #if __cplusplus >= 201103L
00084       template<typename _Up, typename... _Args>
00085         void
00086         construct(_Up* __p, _Args&&... __args)
00087         { ::new((void *)__p) _Up(std::forward<_Args>(__args)...); }
00088 
00089       template<typename _Up>
00090         void 
00091         destroy(_Up* __p) { __p->~_Up(); }
00092 #else
00093       // _GLIBCXX_RESOLVE_LIB_DEFECTS
00094       // 402. wrong new expression in [some_] allocator::construct
00095       void 
00096       construct(pointer __p, const _Tp& __val) 
00097       { ::new((void *)__p) value_type(__val); }
00098 
00099       void 
00100       destroy(pointer __p) { __p->~_Tp(); }
00101 #endif
00102     } _GLIBCXX_DEPRECATED;
00103 
00104   /**
00105    *  @brief  An allocator that uses previously allocated memory.
00106    *  This memory can be externally, globally, or otherwise allocated.
00107    *  @ingroup allocators
00108    */
00109   template<typename _Tp, typename _Array = std::tr1::array<_Tp, 1> >
00110     class array_allocator : public array_allocator_base<_Tp>
00111     {
00112     public:
00113       typedef size_t            size_type;
00114       typedef ptrdiff_t         difference_type;
00115       typedef _Tp*              pointer;
00116       typedef const _Tp*        const_pointer;
00117       typedef _Tp&              reference;
00118       typedef const _Tp&        const_reference;
00119       typedef _Tp               value_type;
00120       typedef _Array            array_type;
00121 
00122 #if __cplusplus >= 201103L
00123       // _GLIBCXX_RESOLVE_LIB_DEFECTS
00124       // 2103. std::allocator propagate_on_container_move_assignment
00125       typedef std::true_type propagate_on_container_move_assignment;
00126 #endif
00127 
00128     private:
00129       array_type*       _M_array;
00130       size_type         _M_used;
00131 
00132     public:
00133      template<typename _Tp1, typename _Array1 = _Array>
00134         struct rebind
00135         {
00136           typedef array_allocator<_Tp1, _Array1> other _GLIBCXX_DEPRECATED;
00137         } _GLIBCXX_DEPRECATED;
00138 
00139       array_allocator(array_type* __array = 0) _GLIBCXX_USE_NOEXCEPT 
00140       : _M_array(__array), _M_used(size_type()) { }
00141 
00142       array_allocator(const array_allocator& __o) _GLIBCXX_USE_NOEXCEPT 
00143       : _M_array(__o._M_array), _M_used(__o._M_used) { }
00144 
00145       template<typename _Tp1, typename _Array1>
00146         array_allocator(const array_allocator<_Tp1, _Array1>&)
00147         _GLIBCXX_USE_NOEXCEPT
00148         : _M_array(0), _M_used(size_type()) { }
00149 
00150       ~array_allocator() _GLIBCXX_USE_NOEXCEPT { }
00151 
00152       pointer
00153       allocate(size_type __n, const void* = 0)
00154       {
00155         if (_M_array == 0 || _M_used + __n > _M_array->size())
00156           std::__throw_bad_alloc();
00157         pointer __ret = _M_array->begin() + _M_used;
00158         _M_used += __n;
00159         return __ret;
00160       }
00161     } _GLIBCXX_DEPRECATED;
00162 
00163   template<typename _Tp, typename _Array>
00164     inline bool
00165     operator==(const array_allocator<_Tp, _Array>&,
00166                const array_allocator<_Tp, _Array>&)
00167     { return true; }
00168   
00169   template<typename _Tp, typename _Array>
00170     inline bool
00171     operator!=(const array_allocator<_Tp, _Array>&, 
00172                const array_allocator<_Tp, _Array>&)
00173     { return false; }
00174 
00175 _GLIBCXX_END_NAMESPACE_VERSION
00176 } // namespace
00177 
00178 #pragma GCC diagnostic pop
00179 
00180 #endif