// <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 */