// <memory> -*- C++ -*-
// Copyright (C) 2001-2020 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.
* @ingroup memory
*/
#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>
#include <bits/ranges_uninitialized.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 <bits/alloc_traits.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>
#if __cplusplus > 201703L
# include <bit> // for has_single_bit
# include <new> // for placement operator new
# include <tuple> // for tuple, make_tuple, make_from_tuple
#endif
namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
/**
* @brief Fit aligned storage in buffer.
* @ingroup memory
*
* 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.
*
* C++11 20.6.5 [ptr.align]
*
* @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
{
#ifdef _GLIBCXX_USE_C99_STDINT_TR1
const auto __intptr = reinterpret_cast<uintptr_t>(__ptr);
#else
// Cannot use std::uintptr_t so assume that std::size_t can be used instead.
static_assert(sizeof(size_t) >= sizeof(void*),
"std::size_t must be a suitable substitute for std::uintptr_t");
const auto __intptr = reinterpret_cast<unsigned long long>(__ptr);
#endif
const auto __aligned = (__intptr - 1u + __align) & -__align;
const auto __diff = __aligned - __intptr;
if ((__size + __diff) > __space)
return nullptr;
else
{
__space -= __diff;
return __ptr = reinterpret_cast<void*>(__aligned);
}
}
/** @defgroup ptr_safety Pointer Safety and Garbage Collection
* @ingroup memory
*
* Utilities to assist with garbage collection in an implementation
* that supports <em>strict pointer safety</em>.
* This implementation only supports <em>relaxed pointer safety</em>
* and so these functions have no effect.
*
* C++11 20.6.4 [util.dynamic.safety], Pointer safety
*
* @{
*/
/// Constants representing the different types of pointer safety.
enum class pointer_safety { relaxed, preferred, strict };
/// Inform a garbage collector that an object is still in use.
inline void
declare_reachable(void*) { }
/// Unregister an object previously registered with declare_reachable.
template <typename _Tp>
inline _Tp*
undeclare_reachable(_Tp* __p) { return __p; }
/// Inform a garbage collector that a region of memory need not be traced.
inline void
declare_no_pointers(char*, size_t) { }
/// Unregister a range previously registered with declare_no_pointers.
inline void
undeclare_no_pointers(char*, size_t) { }
/// The type of pointer safety supported by the implementation.
inline pointer_safety
get_pointer_safety() noexcept { return pointer_safety::relaxed; }
/// @}
#if __cplusplus > 201703L
#define __cpp_lib_assume_aligned 201811L
/** @brief Inform the compiler that a pointer is aligned.
*
* @tparam _Align An alignment value (i.e. a power of two)
* @tparam _Tp An object type
* @param __ptr A pointer that is aligned to _Align
*
* C++20 20.10.6 [ptr.align]
*
* @ingroup memory
*/
template<size_t _Align, class _Tp>
[[nodiscard,__gnu__::__always_inline__]]
constexpr _Tp*
assume_aligned(_Tp* __ptr) noexcept
{
static_assert(std::has_single_bit(_Align));
if (std::is_constant_evaluated())
return __ptr;
else
{
// This function is expected to be used in hot code, where
// __glibcxx_assert would add unwanted overhead.
_GLIBCXX_DEBUG_ASSERT((std::uintptr_t)__ptr % _Align == 0);
return static_cast<_Tp*>(__builtin_assume_aligned(__ptr, _Align));
}
}
#endif // C++2a
#if __cplusplus > 201703L
template<typename _Tp>
struct __is_pair : false_type { };
template<typename _Tp, typename _Up>
struct __is_pair<pair<_Tp, _Up>> : true_type { };
template<typename _Tp, typename _Up>
struct __is_pair<const pair<_Tp, _Up>> : true_type { };
/** @addtogroup allocators
* @{
*/
template<typename _Tp, typename __ = _Require<__not_<__is_pair<_Tp>>>,
typename _Alloc, typename... _Args>
constexpr auto
__uses_alloc_args(const _Alloc& __a, _Args&&... __args) noexcept
{
if constexpr (uses_allocator_v<remove_cv_t<_Tp>, _Alloc>)
{
if constexpr (is_constructible_v<_Tp, allocator_arg_t,
const _Alloc&, _Args...>)
{
return tuple<allocator_arg_t, const _Alloc&, _Args&&...>(
allocator_arg, __a, std::forward<_Args>(__args)...);
}
else
{
static_assert(is_constructible_v<_Tp, _Args..., const _Alloc&>,
"construction with an allocator must be possible"
" if uses_allocator is true");
return tuple<_Args&&..., const _Alloc&>(
std::forward<_Args>(__args)..., __a);
}
}
else
{
static_assert(is_constructible_v<_Tp, _Args...>);
return tuple<_Args&&...>(std::forward<_Args>(__args)...);
}
}
#if __cpp_concepts
template<typename _Tp>
concept _Std_pair = __is_pair<_Tp>::value;
#endif
// This is a temporary workaround until -fconcepts is implied by -std=gnu++2a
#if __cpp_concepts
# define _GLIBCXX_STD_PAIR_CONSTRAINT(T) _Std_pair T
# define _GLIBCXX_STD_PAIR_CONSTRAINT_(T) _Std_pair T
#else
# define _GLIBCXX_STD_PAIR_CONSTRAINT(T) \
typename T, typename __ = _Require<__is_pair<T>>
# define _GLIBCXX_STD_PAIR_CONSTRAINT_(T) typename T, typename
#endif
template<typename _Tp,
#if ! __cpp_concepts
typename __ = _Require<__not_<__is_pair<_Tp>>>,
#endif
typename _Alloc, typename... _Args>
constexpr auto
uses_allocator_construction_args(const _Alloc& __a,
_Args&&... __args) noexcept
#if __cpp_concepts
requires (! _Std_pair<_Tp>)
#endif
{
return std::__uses_alloc_args<_Tp>(__a, std::forward<_Args>(__args)...);
}
template<_GLIBCXX_STD_PAIR_CONSTRAINT(_Tp), typename _Alloc,
typename _Tuple1, typename _Tuple2>
constexpr auto
uses_allocator_construction_args(const _Alloc& __a, piecewise_construct_t,
_Tuple1&& __x, _Tuple2&& __y) noexcept;
template<_GLIBCXX_STD_PAIR_CONSTRAINT(_Tp), typename _Alloc>
constexpr auto
uses_allocator_construction_args(const _Alloc&) noexcept;
template<_GLIBCXX_STD_PAIR_CONSTRAINT(_Tp), typename _Alloc,
typename _Up, typename _Vp>
constexpr auto
uses_allocator_construction_args(const _Alloc&, _Up&&, _Vp&&) noexcept;
template<_GLIBCXX_STD_PAIR_CONSTRAINT(_Tp), typename _Alloc,
typename _Up, typename _Vp>
constexpr auto
uses_allocator_construction_args(const _Alloc&,
const pair<_Up, _Vp>&) noexcept;
template<_GLIBCXX_STD_PAIR_CONSTRAINT(_Tp), typename _Alloc,
typename _Up, typename _Vp>
constexpr auto
uses_allocator_construction_args(const _Alloc&, pair<_Up, _Vp>&&) noexcept;
template<_GLIBCXX_STD_PAIR_CONSTRAINT_(_Tp), typename _Alloc,
typename _Tuple1, typename _Tuple2>
constexpr auto
uses_allocator_construction_args(const _Alloc& __a, piecewise_construct_t,
_Tuple1&& __x, _Tuple2&& __y) noexcept
{
using _Tp1 = typename _Tp::first_type;
using _Tp2 = typename _Tp::second_type;
return std::make_tuple(piecewise_construct,
std::apply([&__a](auto&&... __args1) {
return std::uses_allocator_construction_args<_Tp1>(
__a, std::forward<decltype(__args1)>(__args1)...);
}, std::forward<_Tuple1>(__x)),
std::apply([&__a](auto&&... __args2) {
return std::uses_allocator_construction_args<_Tp2>(
__a, std::forward<decltype(__args2)>(__args2)...);
}, std::forward<_Tuple2>(__y)));
}
template<_GLIBCXX_STD_PAIR_CONSTRAINT_(_Tp), typename _Alloc>
constexpr auto
uses_allocator_construction_args(const _Alloc& __a) noexcept
{
using _Tp1 = typename _Tp::first_type;
using _Tp2 = typename _Tp::second_type;
return std::make_tuple(piecewise_construct,
std::uses_allocator_construction_args<_Tp1>(__a),
std::uses_allocator_construction_args<_Tp2>(__a));
}
template<_GLIBCXX_STD_PAIR_CONSTRAINT_(_Tp), typename _Alloc,
typename _Up, typename _Vp>
constexpr auto
uses_allocator_construction_args(const _Alloc& __a, _Up&& __u, _Vp&& __v)
noexcept
{
using _Tp1 = typename _Tp::first_type;
using _Tp2 = typename _Tp::second_type;
return std::make_tuple(piecewise_construct,
std::uses_allocator_construction_args<_Tp1>(__a,
std::forward<_Up>(__u)),
std::uses_allocator_construction_args<_Tp2>(__a,
std::forward<_Vp>(__v)));
}
template<_GLIBCXX_STD_PAIR_CONSTRAINT_(_Tp), typename _Alloc,
typename _Up, typename _Vp>
constexpr auto
uses_allocator_construction_args(const _Alloc& __a,
const pair<_Up, _Vp>& __pr) noexcept
{
using _Tp1 = typename _Tp::first_type;
using _Tp2 = typename _Tp::second_type;
return std::make_tuple(piecewise_construct,
std::uses_allocator_construction_args<_Tp1>(__a, __pr.first),
std::uses_allocator_construction_args<_Tp2>(__a, __pr.second));
}
template<_GLIBCXX_STD_PAIR_CONSTRAINT_(_Tp), typename _Alloc,
typename _Up, typename _Vp>
constexpr auto
uses_allocator_construction_args(const _Alloc& __a,
pair<_Up, _Vp>&& __pr) noexcept
{
using _Tp1 = typename _Tp::first_type;
using _Tp2 = typename _Tp::second_type;
return std::make_tuple(piecewise_construct,
std::uses_allocator_construction_args<_Tp1>(__a,
std::move(__pr).first),
std::uses_allocator_construction_args<_Tp2>(__a,
std::move(__pr).second));
}
template<typename _Tp, typename _Alloc, typename... _Args>
inline _Tp
make_obj_using_allocator(const _Alloc& __a, _Args&&... __args)
{
return std::make_from_tuple<_Tp>(
std::uses_allocator_construction_args<_Tp>(__a,
std::forward<_Args>(__args)...));
}
template<typename _Tp, typename _Alloc, typename... _Args>
inline _Tp*
uninitialized_construct_using_allocator(_Tp* __p, const _Alloc& __a,
_Args&&... __args)
{
return std::apply([&](auto&&... __xs) {
return std::construct_at(__p, std::forward<decltype(__xs)>(__xs)...);
}, std::uses_allocator_construction_args<_Tp>(__a,
std::forward<_Args>(__args)...));
}
// @}
#endif // C++2a
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace
#endif // C++11
#if __cplusplus > 201402L
// Parallel STL algorithms
# if _PSTL_EXECUTION_POLICIES_DEFINED
// If <execution> has already been included, pull in implementations
# include <pstl/glue_memory_impl.h>
# else
// Otherwise just pull in forward declarations
# include <pstl/glue_memory_defs.h>
# endif
// Feature test macro for parallel algorithms
# define __cpp_lib_parallel_algorithm 201603L
#endif // C++17
#endif /* _GLIBCXX_MEMORY */