libstdc++-v3/include/ext/memory

   1 // Memory extensions -*- C++ -*-
   2
   3 // Copyright (C) 2002-2020 Free Software Foundation, Inc.
   4 //
   5 // This file is part of the GNU ISO C++ Library.  This library is free
   6 // software; you can redistribute it and/or modify it under the
   7 // terms of the GNU General Public License as published by the
   8 // Free Software Foundation; either version 3, or (at your option)
   9 // any later version.
  10
  11 // This library is distributed in the hope that it will be useful,
  12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 // GNU General Public License for more details.
  15
  16 // Under Section 7 of GPL version 3, you are granted additional
  17 // permissions described in the GCC Runtime Library Exception, version
  18 // 3.1, as published by the Free Software Foundation.
  19
  20 // You should have received a copy of the GNU General Public License and
  21 // a copy of the GCC Runtime Library Exception along with this program;
  22 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  23 // <http://www.gnu.org/licenses/>.
  24
  25 /*
  26  *
  27  * Copyright (c) 1994
  28  * Hewlett-Packard Company
  29  *
  30  * Permission to use, copy, modify, distribute and sell this software
  31  * and its documentation for any purpose is hereby granted without fee,
  32  * provided that the above copyright notice appear in all copies and
  33  * that both that copyright notice and this permission notice appear
  34  * in supporting documentation.  Hewlett-Packard Company makes no
  35  * representations about the suitability of this software for any
  36  * purpose.  It is provided "as is" without express or implied warranty.
  37  *
  38  *
  39  * Copyright (c) 1996
  40  * Silicon Graphics Computer Systems, Inc.
  41  *
  42  * Permission to use, copy, modify, distribute and sell this software
  43  * and its documentation for any purpose is hereby granted without fee,
  44  * provided that the above copyright notice appear in all copies and
  45  * that both that copyright notice and this permission notice appear
  46  * in supporting documentation.  Silicon Graphics makes no
  47  * representations about the suitability of this software for any
  48  * purpose.  It is provided "as is" without express or implied warranty.
  49  */
  50
  51 /** @file ext/memory
  52  *  This file is a GNU extension to the Standard C++ Library (possibly
  53  *  containing extensions from the HP/SGI STL subset).
  54  */
  55
  56 #ifndef _EXT_MEMORY
  57 #define _EXT_MEMORY 1
  58
  59 #pragma GCC system_header
  60
  61 #include <memory>
  62 #include <bits/stl_tempbuf.h>
  63
  64 namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
  65 {
  66 _GLIBCXX_BEGIN_NAMESPACE_VERSION
  67
  68   using std::_Temporary_buffer;
  69
  70   template<typename _InputIter, typename _Size, typename _ForwardIter>
  71     std::pair<_InputIter, _ForwardIter>
  72     __uninitialized_copy_n(_InputIter __first, _Size __count,
  73                            _ForwardIter __result, std::input_iterator_tag)
  74     {
  75       _ForwardIter __cur = __result;
  76       __try
  77         {
  78           for (; __count > 0 ; --__count, ++__first, ++__cur)
  79             std::_Construct(&*__cur, *__first);
  80           return std::pair<_InputIter, _ForwardIter>(__first, __cur);
  81         }
  82       __catch(...)
  83         {
  84           std::_Destroy(__result, __cur);
  85           __throw_exception_again;
  86         }
  87     }
  88
  89   template<typename _RandomAccessIter, typename _Size, typename _ForwardIter>
  90     inline std::pair<_RandomAccessIter, _ForwardIter>
  91     __uninitialized_copy_n(_RandomAccessIter __first, _Size __count,
  92                            _ForwardIter __result,
  93                            std::random_access_iterator_tag)
  94     {
  95       _RandomAccessIter __last = __first + __count;
  96       return (std::pair<_RandomAccessIter, _ForwardIter>
  97               (__last, std::uninitialized_copy(__first, __last, __result)));
  98     }
  99
 100   template<typename _InputIter, typename _Size, typename _ForwardIter>
 101     inline std::pair<_InputIter, _ForwardIter>
 102     __uninitialized_copy_n(_InputIter __first, _Size __count,
 103                            _ForwardIter __result)
 104     {
 105       return __gnu_cxx::__uninitialized_copy_n(__first, __count, __result,
 106           std::__iterator_category(__first));
 107     }
 108
 109   /**
 110    *  @brief Copies the range [first,last) into result.
 111    *  @param  __first  An input iterator.
 112    *  @param  __count  Length
 113    *  @param  __result An output iterator.
 114    *  @return   __result + (__first + __count)
 115    *  @ingroup SGIextensions
 116    *
 117    *  Like copy(), but does not require an initialized output range.
 118   */
 119   template<typename _InputIter, typename _Size, typename _ForwardIter>
 120     inline std::pair<_InputIter, _ForwardIter>
 121     uninitialized_copy_n(_InputIter __first, _Size __count,
 122                          _ForwardIter __result)
 123     {
 124       return __gnu_cxx::__uninitialized_copy_n(__first, __count, __result,
 125           std::__iterator_category(__first));
 126     }
 127
 128
 129   // An alternative version of uninitialized_copy_n that constructs
 130   // and destroys objects with a user-provided allocator.
 131   template<typename _InputIter, typename _Size, typename _ForwardIter,
 132            typename _Allocator>
 133     std::pair<_InputIter, _ForwardIter>
 134     __uninitialized_copy_n_a(_InputIter __first, _Size __count,
 135                              _ForwardIter __result,
 136                              _Allocator __alloc)
 137     {
 138       _ForwardIter __cur = __result;
 139       __try
 140         {
 141           for (; __count > 0 ; --__count, ++__first, ++__cur)
 142             __alloc.construct(&*__cur, *__first);
 143           return std::pair<_InputIter, _ForwardIter>(__first, __cur);
 144         }
 145       __catch(...)
 146         {
 147           std::_Destroy(__result, __cur, __alloc);
 148           __throw_exception_again;
 149         }
 150     }
 151
 152   template<typename _InputIter, typename _Size, typename _ForwardIter,
 153            typename _Tp>
 154     inline std::pair<_InputIter, _ForwardIter>
 155     __uninitialized_copy_n_a(_InputIter __first, _Size __count,
 156                              _ForwardIter __result,
 157                              std::allocator<_Tp>)
 158     {
 159       return __gnu_cxx::uninitialized_copy_n(__first, __count, __result);
 160     }
 161
 162   /**
 163    *  This class provides similar behavior and semantics of the standard
 164    *  functions get_temporary_buffer() and return_temporary_buffer(), but
 165    *  encapsulated in a type vaguely resembling a standard container.
 166    *
 167    *  By default, a temporary_buffer<Iter> stores space for objects of
 168    *  whatever type the Iter iterator points to.  It is constructed from a
 169    *  typical [first,last) range, and provides the begin(), end(), size()
 170    *  functions, as well as requested_size().  For non-trivial types, copies
 171    *  of *first will be used to initialize the storage.
 172    *
 173    *  @c malloc is used to obtain underlying storage.
 174    *
 175    *  Like get_temporary_buffer(), not all the requested memory may be
 176    *  available.  Ideally, the created buffer will be large enough to hold a
 177    *  copy of [first,last), but if size() is less than requested_size(),
 178    *  then this didn't happen.
 179    *
 180    *  @ingroup SGIextensions
 181   */
 182   template <class _ForwardIterator, class _Tp
 183             = typename std::iterator_traits<_ForwardIterator>::value_type >
 184     struct temporary_buffer : public _Temporary_buffer<_ForwardIterator, _Tp>
 185     {
 186       /// Requests storage large enough to hold a copy of [first,last).
 187       temporary_buffer(_ForwardIterator __first, _ForwardIterator __last)
 188       : _Temporary_buffer<_ForwardIterator, _Tp>(__first,
 189                                                  std::distance(__first, __last))
 190       { }
 191
 192       /// Destroys objects and frees storage.
 193       ~temporary_buffer() { }
 194     };
 195
 196 _GLIBCXX_END_NAMESPACE_VERSION
 197 } // namespace
 198
 199 #endif
 200