libstdc++-v3/include/ext/memory

   1 // Memory extensions -*- C++ -*-
   2
   3 // Copyright (C) 2002, 2004, 2005 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 2, 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 // You should have received a copy of the GNU General Public License along
  17 // with this library; see the file COPYING.  If not, write to the Free
  18 // Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
  19 // USA.
  20
  21 // As a special exception, you may use this file as part of a free software
  22 // library without restriction.  Specifically, if other files instantiate
  23 // templates or use macros or inline functions from this file, or you compile
  24 // this file and link it with other files to produce an executable, this
  25 // file does not by itself cause the resulting executable to be covered by
  26 // the GNU General Public License.  This exception does not however
  27 // invalidate any other reasons why the executable file might be covered by
  28 // the GNU General Public License.
  29
  30 /*
  31  *
  32  * Copyright (c) 1994
  33  * Hewlett-Packard Company
  34  *
  35  * Permission to use, copy, modify, distribute and sell this software
  36  * and its documentation for any purpose is hereby granted without fee,
  37  * provided that the above copyright notice appear in all copies and
  38  * that both that copyright notice and this permission notice appear
  39  * in supporting documentation.  Hewlett-Packard Company makes no
  40  * representations about the suitability of this software for any
  41  * purpose.  It is provided "as is" without express or implied warranty.
  42  *
  43  *
  44  * Copyright (c) 1996
  45  * Silicon Graphics Computer Systems, Inc.
  46  *
  47  * Permission to use, copy, modify, distribute and sell this software
  48  * and its documentation for any purpose is hereby granted without fee,
  49  * provided that the above copyright notice appear in all copies and
  50  * that both that copyright notice and this permission notice appear
  51  * in supporting documentation.  Silicon Graphics makes no
  52  * representations about the suitability of this software for any
  53  * purpose.  It is provided "as is" without express or implied warranty.
  54  */
  55
  56 /** @file ext/memory
  57  *  This file is a GNU extension to the Standard C++ Library (possibly
  58  *  containing extensions from the HP/SGI STL subset).
  59  */
  60
  61 #ifndef _EXT_MEMORY
  62 #define _EXT_MEMORY 1
  63
  64 #pragma GCC system_header
  65
  66 #include <memory>
  67 #include <bits/stl_tempbuf.h>
  68
  69 _GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx)
  70
  71   using std::ptrdiff_t;
  72   using std::pair;
  73   using std::__iterator_category;
  74   using std::_Temporary_buffer;
  75
  76   template<typename _InputIter, typename _Size, typename _ForwardIter>
  77     pair<_InputIter, _ForwardIter>
  78     __uninitialized_copy_n(_InputIter __first, _Size __count,
  79                            _ForwardIter __result, std::input_iterator_tag)
  80     {
  81       _ForwardIter __cur = __result;
  82       try
  83         {
  84           for (; __count > 0 ; --__count, ++__first, ++__cur)
  85             std::_Construct(&*__cur, *__first);
  86           return pair<_InputIter, _ForwardIter>(__first, __cur);
  87         }
  88       catch(...)
  89         {
  90           std::_Destroy(__result, __cur);
  91           __throw_exception_again;
  92         }
  93     }
  94
  95   template<typename _RandomAccessIter, typename _Size, typename _ForwardIter>
  96     inline pair<_RandomAccessIter, _ForwardIter>
  97     __uninitialized_copy_n(_RandomAccessIter __first, _Size __count,
  98                            _ForwardIter __result,
  99                            std::random_access_iterator_tag)
 100     {
 101       _RandomAccessIter __last = __first + __count;
 102       return (pair<_RandomAccessIter, _ForwardIter>
 103               (__last, std::uninitialized_copy(__first, __last, __result)));
 104     }
 105
 106   template<typename _InputIter, typename _Size, typename _ForwardIter>
 107     inline pair<_InputIter, _ForwardIter>
 108     __uninitialized_copy_n(_InputIter __first, _Size __count,
 109                          _ForwardIter __result)
 110     { return __uninitialized_copy_n(__first, __count, __result,
 111                                     __iterator_category(__first)); }
 112
 113   /**
 114    *  @brief Copies the range [first,last) into result.
 115    *  @param  first  An input iterator.
 116    *  @param  last   An input iterator.
 117    *  @param  result An output iterator.
 118    *  @return   result + (first - last)
 119    *  @ingroup SGIextensions
 120    *
 121    *  Like copy(), but does not require an initialized output range.
 122   */
 123   template<typename _InputIter, typename _Size, typename _ForwardIter>
 124     inline pair<_InputIter, _ForwardIter>
 125     uninitialized_copy_n(_InputIter __first, _Size __count,
 126                          _ForwardIter __result)
 127     { return __uninitialized_copy_n(__first, __count, __result,
 128                                     __iterator_category(__first)); }
 129
 130
 131   // An alternative version of uninitialized_copy_n that constructs
 132   // and destroys objects with a user-provided allocator.
 133   template<typename _InputIter, typename _Size, typename _ForwardIter,
 134            typename _Allocator>
 135     pair<_InputIter, _ForwardIter>
 136     __uninitialized_copy_n_a(_InputIter __first, _Size __count,
 137                              _ForwardIter __result,
 138                              _Allocator __alloc)
 139     {
 140       _ForwardIter __cur = __result;
 141       try
 142         {
 143           for (; __count > 0 ; --__count, ++__first, ++__cur)
 144             __alloc.construct(&*__cur, *__first);
 145           return pair<_InputIter, _ForwardIter>(__first, __cur);
 146         }
 147       catch(...)
 148         {
 149           std::_Destroy(__result, __cur, __alloc);
 150           __throw_exception_again;
 151         }
 152     }
 153
 154   template<typename _InputIter, typename _Size, typename _ForwardIter,
 155            typename _Tp>
 156     inline pair<_InputIter, _ForwardIter>
 157     __uninitialized_copy_n_a(_InputIter __first, _Size __count,
 158                              _ForwardIter __result,
 159                              std::allocator<_Tp>)
 160     {
 161       return uninitialized_copy_n(__first, __count, __result);
 162     }
 163
 164   /**
 165    *  This class provides similar behavior and semantics of the standard
 166    *  functions get_temporary_buffer() and return_temporary_buffer(), but
 167    *  encapsulated in a type vaguely resembling a standard container.
 168    *
 169    *  By default, a temporary_buffer<Iter> stores space for objects of
 170    *  whatever type the Iter iterator points to.  It is constructed from a
 171    *  typical [first,last) range, and provides the begin(), end(), size()
 172    *  functions, as well as requested_size().  For non-trivial types, copies
 173    *  of *first will be used to initialize the storage.
 174    *
 175    *  @c malloc is used to obtain underlying storage.
 176    *
 177    *  Like get_temporary_buffer(), not all the requested memory may be
 178    *  available.  Ideally, the created buffer will be large enough to hold a
 179    *  copy of [first,last), but if size() is less than requested_size(),
 180    *  then this didn't happen.
 181    *
 182    *  @ingroup SGIextensions
 183   */
 184   template <class _ForwardIterator, class _Tp
 185             = typename std::iterator_traits<_ForwardIterator>::value_type >
 186     struct temporary_buffer : public _Temporary_buffer<_ForwardIterator, _Tp>
 187     {
 188       /// Requests storage large enough to hold a copy of [first,last).
 189       temporary_buffer(_ForwardIterator __first, _ForwardIterator __last)
 190       : _Temporary_buffer<_ForwardIterator, _Tp>(__first, __last) { }
 191
 192       /// Destroys objects and frees storage.
 193       ~temporary_buffer() { }
 194     };
 195
 196 _GLIBCXX_END_NAMESPACE
 197
 198 #endif
 199