malloc_allocator.h
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// Allocator that wraps "C" malloc -*- C++ -*-
// Copyright (C) 2001-2018 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/>.
/** @file ext/malloc_allocator.h
* This file is a GNU extension to the Standard C++ Library.
*/
#ifndef _MALLOC_ALLOCATOR_H
#define _MALLOC_ALLOCATOR_H 1
#include <cstdlib>
#include <cstddef>
#include <new>
#include <bits/functexcept.h>
#include <bits/move.h>
#if __cplusplus >= 201103L
#include <type_traits>
#endif
namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
using std::size_t;
using std::ptrdiff_t;
/**
* @brief An allocator that uses malloc.
* @ingroup allocators
*
* This is precisely the allocator defined in the C++ Standard.
* - all allocation calls malloc
* - all deallocation calls free
*/
template<typename _Tp>
class malloc_allocator
{
public:
typedef size_t size_type;
typedef ptrdiff_t difference_type;
typedef _Tp* pointer;
typedef const _Tp* const_pointer;
typedef _Tp& reference;
typedef const _Tp& const_reference;
typedef _Tp value_type;
template<typename _Tp1>
struct rebind
{ typedef malloc_allocator<_Tp1> other; };
#if __cplusplus >= 201103L
// _GLIBCXX_RESOLVE_LIB_DEFECTS
// 2103. propagate_on_container_move_assignment
typedef std::true_type propagate_on_container_move_assignment;
#endif
malloc_allocator() _GLIBCXX_USE_NOEXCEPT { }
malloc_allocator(const malloc_allocator&) _GLIBCXX_USE_NOEXCEPT { }
template<typename _Tp1>
malloc_allocator(const malloc_allocator<_Tp1>&)
_GLIBCXX_USE_NOEXCEPT { }
~malloc_allocator() _GLIBCXX_USE_NOEXCEPT { }
pointer
address(reference __x) const _GLIBCXX_NOEXCEPT
{ return std::__addressof(__x); }
const_pointer
address(const_reference __x) const _GLIBCXX_NOEXCEPT
{ return std::__addressof(__x); }
// NB: __n is permitted to be 0. The C++ standard says nothing
// about what the return value is when __n == 0.
pointer
allocate(size_type __n, const void* = 0)
{
if (__n > this->max_size())
std::__throw_bad_alloc();
pointer __ret = 0;
#if __cpp_aligned_new
#if __cplusplus > 201402L && _GLIBCXX_HAVE_ALIGNED_ALLOC
if (alignof(_Tp) > alignof(std::max_align_t))
{
__ret = static_cast<_Tp*>(::aligned_alloc(alignof(_Tp),
__n * sizeof(_Tp)));
}
#else
# define _GLIBCXX_CHECK_MALLOC_RESULT
#endif
#endif
if (!__ret)
__ret = static_cast<_Tp*>(std::malloc(__n * sizeof(_Tp)));
if (!__ret)
std::__throw_bad_alloc();
#ifdef _GLIBCXX_CHECK_MALLOC_RESULT
#undef _GLIBCXX_CHECK_MALLOC_RESULT
if (reinterpret_cast<std::size_t>(__ret) % alignof(_Tp))
{
// Memory returned by malloc is not suitably aligned for _Tp.
deallocate(__ret, __n);
std::__throw_bad_alloc();
}
#endif
return __ret;
}
// __p is not permitted to be a null pointer.
void
deallocate(pointer __p, size_type)
{ std::free(static_cast<void*>(__p)); }
size_type
max_size() const _GLIBCXX_USE_NOEXCEPT
{ return size_t(-1) / sizeof(_Tp); }
#if __cplusplus >= 201103L
template<typename _Up, typename... _Args>
void
construct(_Up* __p, _Args&&... __args)
{ ::new((void *)__p) _Up(std::forward<_Args>(__args)...); }
template<typename _Up>
void
destroy(_Up* __p) { __p->~_Up(); }
#else
// _GLIBCXX_RESOLVE_LIB_DEFECTS
// 402. wrong new expression in [some_] allocator::construct
void
construct(pointer __p, const _Tp& __val)
{ ::new((void *)__p) value_type(__val); }
void
destroy(pointer __p) { __p->~_Tp(); }
#endif
};
template<typename _Tp>
inline bool
operator==(const malloc_allocator<_Tp>&, const malloc_allocator<_Tp>&)
{ return true; }
template<typename _Tp>
inline bool
operator!=(const malloc_allocator<_Tp>&, const malloc_allocator<_Tp>&)
{ return false; }
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace
#endif
move.h
__gnu_cxx::malloc_allocator
An allocator that uses malloc.This is precisely the allocator defined in the C++ Standard.
Definition: malloc_allocator.h:57
functexcept.h
cstdlib
__gnu_cxx
GNU extensions for public use.
type_traits
std::__addressof
constexpr _Tp * __addressof(_Tp &__r) noexcept
Same as C++11 std::addressof.
Definition: move.h:47
new
std::integral_constant
integral_constant
Definition: type_traits:69
cstddef