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      1 // Memory extensions -*- C++ -*-
      2 
      3 // Copyright (C) 2002-2024 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 <bits/requires_hosted.h> // GNU extensions are currently omitted
     62 
     63 #include <memory>
     64 #include <bits/stl_tempbuf.h>
     65 
     66 namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
     67 {
     68 _GLIBCXX_BEGIN_NAMESPACE_VERSION
     69 
     70   using std::_Temporary_buffer;
     71 
     72   template<typename _InputIter, typename _Size, typename _ForwardIter>
     73     std::pair<_InputIter, _ForwardIter>
     74     __uninitialized_copy_n(_InputIter __first, _Size __count,
     75 			   _ForwardIter __result, std::input_iterator_tag)
     76     {
     77       _ForwardIter __cur = __result;
     78       __try
     79 	{
     80 	  for (; __count > 0 ; --__count, ++__first, ++__cur)
     81 	    std::_Construct(&*__cur, *__first);
     82 	  return std::pair<_InputIter, _ForwardIter>(__first, __cur);
     83 	}
     84       __catch(...)
     85 	{
     86 	  std::_Destroy(__result, __cur);
     87 	  __throw_exception_again;
     88 	}
     89     }
     90 
     91   template<typename _RandomAccessIter, typename _Size, typename _ForwardIter>
     92     inline std::pair<_RandomAccessIter, _ForwardIter>
     93     __uninitialized_copy_n(_RandomAccessIter __first, _Size __count,
     94 			   _ForwardIter __result,
     95 			   std::random_access_iterator_tag)
     96     {
     97       _RandomAccessIter __last = __first + __count;
     98       return (std::pair<_RandomAccessIter, _ForwardIter>
     99 	      (__last, std::uninitialized_copy(__first, __last, __result)));
    100     }
    101 
    102   template<typename _InputIter, typename _Size, typename _ForwardIter>
    103     inline std::pair<_InputIter, _ForwardIter>
    104     __uninitialized_copy_n(_InputIter __first, _Size __count,
    105 			   _ForwardIter __result)
    106     {
    107       return __gnu_cxx::__uninitialized_copy_n(__first, __count, __result,
    108 	  std::__iterator_category(__first));
    109     }
    110 
    111   /**
    112    *  @brief Copies the range [first,last) into result.
    113    *  @param  __first  An input iterator.
    114    *  @param  __count  Length
    115    *  @param  __result An output iterator.
    116    *  @return   __result + (__first + __count)
    117    *  @ingroup SGIextensions
    118    *
    119    *  Like copy(), but does not require an initialized output range.
    120   */
    121   template<typename _InputIter, typename _Size, typename _ForwardIter>
    122     inline std::pair<_InputIter, _ForwardIter>
    123     uninitialized_copy_n(_InputIter __first, _Size __count,
    124 			 _ForwardIter __result)
    125     {
    126       return __gnu_cxx::__uninitialized_copy_n(__first, __count, __result,
    127 	  std::__iterator_category(__first));
    128     }
    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     std::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 std::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 std::pair<_InputIter, _ForwardIter>
    157     __uninitialized_copy_n_a(_InputIter __first, _Size __count,
    158 			     _ForwardIter __result,
    159 			     std::allocator<_Tp>)
    160     {
    161       return __gnu_cxx::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,
    191 						 std::distance(__first, __last))
    192       { }
    193       
    194       /// Destroys objects and frees storage.
    195       ~temporary_buffer() { }
    196     };
    197 
    198 _GLIBCXX_END_NAMESPACE_VERSION
    199 } // namespace
    200 
    201 #endif
    202 
    203