gcc/libstdc++-v3/include/std/memory

// <memory> -*- C++ -*-

// Copyright (C) 2001-2017 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library.  This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
// any later version.

// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.

// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
// <http://www.gnu.org/licenses/>.

/*
 * Copyright (c) 1997-1999
 * Silicon Graphics Computer Systems, Inc.
 *
 * Permission to use, copy, modify, distribute and sell this software
 * and its documentation for any purpose is hereby granted without fee,
 * provided that the above copyright notice appear in all copies and
 * that both that copyright notice and this permission notice appear
 * in supporting documentation.  Silicon Graphics makes no
 * representations about the suitability of this software for any
 * purpose.  It is provided "as is" without express or implied warranty.
 *
 */

/** @file include/memory
 *  This is a Standard C++ Library header.
 */

#ifndef _GLIBCXX_MEMORY
#define _GLIBCXX_MEMORY 1

#pragma GCC system_header

/**
 * @defgroup memory Memory
 * @ingroup utilities
 *
 * Components for memory allocation, deallocation, and management.
 */

/**
 * @defgroup pointer_abstractions Pointer Abstractions
 * @ingroup memory
 *
 * Smart pointers, etc.
 */

#include <bits/stl_algobase.h>
#include <bits/allocator.h>
#include <bits/stl_construct.h>
#include <bits/stl_uninitialized.h>
#include <bits/stl_tempbuf.h>
#include <bits/stl_raw_storage_iter.h>

#if __cplusplus >= 201103L
#  include <exception>        	  // std::exception
#  include <typeinfo>         	  // std::type_info in get_deleter
#  include <iosfwd>           	  // std::basic_ostream
#  include <ext/atomicity.h>
#  include <ext/concurrence.h>
#  include <bits/functexcept.h>
#  include <bits/stl_function.h>  // std::less
#  include <bits/uses_allocator.h>
#  include <type_traits>
#  include <debug/debug.h>
#  include <bits/unique_ptr.h>
#  include <bits/shared_ptr.h>
#  include <bits/shared_ptr_atomic.h>
#  if _GLIBCXX_USE_DEPRECATED
#    include <backward/auto_ptr.h>
#  endif
#else
#  include <backward/auto_ptr.h>
#endif

#if __cplusplus >= 201103L
#  include <cstdint>
#  ifdef _GLIBCXX_USE_C99_STDINT_TR1
namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION

/**
 *  @brief Fit aligned storage in buffer.
 *
 *  [ptr.align]
 *
 *  This function tries to fit @a __size bytes of storage with alignment
 *  @a __align into the buffer @a __ptr of size @a __space bytes.  If such
 *  a buffer fits then @a __ptr is changed to point to the first byte of the
 *  aligned storage and @a __space is reduced by the bytes used for alignment.
 *
 *  @param __align   A fundamental or extended alignment value.
 *  @param __size    Size of the aligned storage required.
 *  @param __ptr     Pointer to a buffer of @a __space bytes.
 *  @param __space   Size of the buffer pointed to by @a __ptr.
 *  @return the updated pointer if the aligned storage fits, otherwise nullptr.
 */
inline void*
align(size_t __align, size_t __size, void*& __ptr, size_t& __space) noexcept
{
  const auto __intptr = reinterpret_cast<uintptr_t>(__ptr);
  const auto __aligned = (__intptr - 1u + __align) & -__align;
  const auto __diff = __aligned - __intptr;
  if ((__size + __diff) > __space)
    return nullptr;
  else
    {
      __space -= __diff;
#if defined(__LCC__) && defined(__ptr128__)
      return __ptr = __ptr + __diff;
#else
      return __ptr = reinterpret_cast<void*>(__aligned);
#endif
    }
}

// 20.7.4 [util.dynamic.safety], pointer safety

enum class pointer_safety { relaxed, preferred, strict };

inline void
declare_reachable(void*) { }

template <typename _Tp>
  inline _Tp*
  undeclare_reachable(_Tp* __p) { return __p; }

inline void
declare_no_pointers(char*, size_t) { }

inline void
undeclare_no_pointers(char*, size_t) { }

inline pointer_safety
get_pointer_safety() noexcept { return pointer_safety::relaxed; }

_GLIBCXX_END_NAMESPACE_VERSION
} // namespace
#endif // _GLIBCXX_USE_C99_STDINT_TR1
#endif // C++11

#endif /* _GLIBCXX_MEMORY */