libstdc++
memory
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00001 // <memory> -*- C++ -*-
00002 
00003 // Copyright (C) 2001-2015 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 /*
00026  * Copyright (c) 1997-1999
00027  * Silicon Graphics Computer Systems, Inc.
00028  *
00029  * Permission to use, copy, modify, distribute and sell this software
00030  * and its documentation for any purpose is hereby granted without fee,
00031  * provided that the above copyright notice appear in all copies and
00032  * that both that copyright notice and this permission notice appear
00033  * in supporting documentation.  Silicon Graphics makes no
00034  * representations about the suitability of this software for any
00035  * purpose.  It is provided "as is" without express or implied warranty.
00036  *
00037  */
00038 
00039 /** @file include/memory
00040  *  This is a Standard C++ Library header.
00041  */
00042 
00043 #ifndef _GLIBCXX_MEMORY
00044 #define _GLIBCXX_MEMORY 1
00045 
00046 #pragma GCC system_header
00047 
00048 /**
00049  * @defgroup memory Memory
00050  * @ingroup utilities
00051  *
00052  * Components for memory allocation, deallocation, and management.
00053  */
00054 
00055 /**
00056  * @defgroup pointer_abstractions Pointer Abstractions
00057  * @ingroup memory
00058  *
00059  * Smart pointers, etc.
00060  */
00061 
00062 #include <bits/stl_algobase.h>
00063 #include <bits/allocator.h>
00064 #include <bits/stl_construct.h>
00065 #include <bits/stl_uninitialized.h>
00066 #include <bits/stl_tempbuf.h>
00067 #include <bits/stl_raw_storage_iter.h>
00068 
00069 #if __cplusplus >= 201103L
00070 #  include <exception>            // std::exception
00071 #  include <typeinfo>             // std::type_info in get_deleter
00072 #  include <iosfwd>               // std::basic_ostream
00073 #  include <ext/atomicity.h>
00074 #  include <ext/concurrence.h>
00075 #  include <bits/functexcept.h>
00076 #  include <bits/stl_function.h>  // std::less
00077 #  include <bits/uses_allocator.h>
00078 #  include <type_traits>
00079 #  include <functional>
00080 #  include <debug/debug.h>
00081 #  include <bits/unique_ptr.h>
00082 #  include <bits/shared_ptr.h>
00083 #  include <bits/shared_ptr_atomic.h>
00084 #  if _GLIBCXX_USE_DEPRECATED
00085 #    include <backward/auto_ptr.h>
00086 #  endif
00087 #else
00088 #  include <backward/auto_ptr.h>
00089 #endif
00090 
00091 #if __cplusplus >= 201103L
00092 #  include <cstdint>
00093 #  ifdef _GLIBCXX_USE_C99_STDINT_TR1
00094 namespace std _GLIBCXX_VISIBILITY(default)
00095 {
00096 _GLIBCXX_BEGIN_NAMESPACE_VERSION
00097 
00098 /**
00099  *  @brief Fit aligned storage in buffer.
00100  *
00101  *  [ptr.align]
00102  *
00103  *  This function tries to fit @a __size bytes of storage with alignment
00104  *  @a __align into the buffer @a __ptr of size @a __space bytes.  If such
00105  *  a buffer fits then @a __ptr is changed to point to the first byte of the
00106  *  aligned storage and @a __space is reduced by the bytes used for alignment.
00107  *
00108  *  @param __align   A fundamental or extended alignment value.
00109  *  @param __size    Size of the aligned storage required.
00110  *  @param __ptr     Pointer to a buffer of @a __space bytes.
00111  *  @param __space   Size of the buffer pointed to by @a __ptr.
00112  *  @return the updated pointer if the aligned storage fits, otherwise nullptr.
00113  */
00114 inline void*
00115 align(size_t __align, size_t __size, void*& __ptr, size_t& __space) noexcept
00116 {
00117   const auto __intptr = reinterpret_cast<uintptr_t>(__ptr);
00118   const auto __aligned = (__intptr - 1u + __align) & -__align;
00119   const auto __diff = __aligned - __intptr;
00120   if ((__size + __diff) > __space)
00121     return nullptr;
00122   else
00123     {
00124       __space -= __diff;
00125       return __ptr = reinterpret_cast<void*>(__aligned);
00126     }
00127 }
00128 
00129 _GLIBCXX_END_NAMESPACE_VERSION
00130 } // namespace
00131 #endif // _GLIBCXX_USE_C99_STDINT_TR1
00132 #endif // C++11
00133 
00134 #endif /* _GLIBCXX_MEMORY */