llvm-project/libcxx/include/__memory/allocator_traits.h
Nikolas Klauser af9c04fa68
[libc++] Remove _LIBCPP_TEMPLATE_VIS (#134885)
The need for `_LIBCPP_TEMPLATE_VIS` has been removed in #133233.
2025-04-09 23:47:57 +02:00

382 lines
15 KiB
C++

// -*- C++ -*-
//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#ifndef _LIBCPP___MEMORY_ALLOCATOR_TRAITS_H
#define _LIBCPP___MEMORY_ALLOCATOR_TRAITS_H
#include <__config>
#include <__cstddef/size_t.h>
#include <__fwd/memory.h>
#include <__memory/construct_at.h>
#include <__memory/pointer_traits.h>
#include <__type_traits/detected_or.h>
#include <__type_traits/enable_if.h>
#include <__type_traits/is_constructible.h>
#include <__type_traits/is_empty.h>
#include <__type_traits/is_same.h>
#include <__type_traits/make_unsigned.h>
#include <__type_traits/remove_reference.h>
#include <__type_traits/void_t.h>
#include <__utility/declval.h>
#include <__utility/forward.h>
#include <limits>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
# pragma GCC system_header
#endif
_LIBCPP_PUSH_MACROS
#include <__undef_macros>
_LIBCPP_BEGIN_NAMESPACE_STD
_LIBCPP_SUPPRESS_DEPRECATED_PUSH
// __pointer
template <class _Tp>
using __pointer_member _LIBCPP_NODEBUG = typename _Tp::pointer;
template <class _Tp, class _Alloc>
using __pointer _LIBCPP_NODEBUG = __detected_or_t<_Tp*, __pointer_member, __libcpp_remove_reference_t<_Alloc> >;
// This trait returns _Alias<_Alloc> if that's well-formed, and _Ptr rebound to _Tp otherwise
template <class _Alloc, template <class> class _Alias, class _Ptr, class _Tp, class = void>
struct __rebind_or_alias_pointer {
#ifdef _LIBCPP_CXX03_LANG
using type _LIBCPP_NODEBUG = typename pointer_traits<_Ptr>::template rebind<_Tp>::other;
#else
using type _LIBCPP_NODEBUG = typename pointer_traits<_Ptr>::template rebind<_Tp>;
#endif
};
template <class _Ptr, class _Alloc, class _Tp, template <class> class _Alias>
struct __rebind_or_alias_pointer<_Alloc, _Alias, _Ptr, _Tp, __void_t<_Alias<_Alloc> > > {
using type _LIBCPP_NODEBUG = _Alias<_Alloc>;
};
// __const_pointer
template <class _Alloc>
using __const_pointer_member _LIBCPP_NODEBUG = typename _Alloc::const_pointer;
template <class _Tp, class _Ptr, class _Alloc>
using __const_pointer_t _LIBCPP_NODEBUG =
typename __rebind_or_alias_pointer<_Alloc, __const_pointer_member, _Ptr, const _Tp>::type;
_LIBCPP_SUPPRESS_DEPRECATED_POP
// __void_pointer
template <class _Alloc>
using __void_pointer_member _LIBCPP_NODEBUG = typename _Alloc::void_pointer;
template <class _Ptr, class _Alloc>
using __void_pointer_t _LIBCPP_NODEBUG =
typename __rebind_or_alias_pointer<_Alloc, __void_pointer_member, _Ptr, void>::type;
// __const_void_pointer
template <class _Alloc>
using __const_void_pointer_member _LIBCPP_NODEBUG = typename _Alloc::const_void_pointer;
template <class _Ptr, class _Alloc>
using __const_void_pointer_t _LIBCPP_NODEBUG =
typename __rebind_or_alias_pointer<_Alloc, __const_void_pointer_member, _Ptr, const void>::type;
// __size_type
template <class _Tp>
using __size_type_member _LIBCPP_NODEBUG = typename _Tp::size_type;
template <class _Alloc, class _DiffType>
using __size_type _LIBCPP_NODEBUG = __detected_or_t<__make_unsigned_t<_DiffType>, __size_type_member, _Alloc>;
// __alloc_traits_difference_type
template <class _Alloc, class _Ptr, class = void>
struct __alloc_traits_difference_type {
using type _LIBCPP_NODEBUG = typename pointer_traits<_Ptr>::difference_type;
};
template <class _Alloc, class _Ptr>
struct __alloc_traits_difference_type<_Alloc, _Ptr, __void_t<typename _Alloc::difference_type> > {
using type _LIBCPP_NODEBUG = typename _Alloc::difference_type;
};
// __propagate_on_container_copy_assignment
template <class _Tp>
using __propagate_on_container_copy_assignment_member _LIBCPP_NODEBUG =
typename _Tp::propagate_on_container_copy_assignment;
template <class _Alloc>
using __propagate_on_container_copy_assignment _LIBCPP_NODEBUG =
__detected_or_t<false_type, __propagate_on_container_copy_assignment_member, _Alloc>;
// __propagate_on_container_move_assignment
template <class _Tp>
using __propagate_on_container_move_assignment_member _LIBCPP_NODEBUG =
typename _Tp::propagate_on_container_move_assignment;
template <class _Alloc>
using __propagate_on_container_move_assignment _LIBCPP_NODEBUG =
__detected_or_t<false_type, __propagate_on_container_move_assignment_member, _Alloc>;
// __propagate_on_container_swap
template <class _Tp>
using __propagate_on_container_swap_member _LIBCPP_NODEBUG = typename _Tp::propagate_on_container_swap;
template <class _Alloc>
using __propagate_on_container_swap _LIBCPP_NODEBUG =
__detected_or_t<false_type, __propagate_on_container_swap_member, _Alloc>;
_LIBCPP_SUPPRESS_DEPRECATED_PUSH
// __is_always_equal
template <class _Tp>
using __is_always_equal_member _LIBCPP_NODEBUG = typename _Tp::is_always_equal;
template <class _Alloc>
using __is_always_equal _LIBCPP_NODEBUG =
__detected_or_t<typename is_empty<_Alloc>::type, __is_always_equal_member, _Alloc>;
// __allocator_traits_rebind
template <class _Tp, class _Up, class = void>
inline const bool __has_rebind_other_v = false;
template <class _Tp, class _Up>
inline const bool __has_rebind_other_v<_Tp, _Up, __void_t<typename _Tp::template rebind<_Up>::other> > = true;
template <class _Tp, class _Up, bool = __has_rebind_other_v<_Tp, _Up> >
struct __allocator_traits_rebind {
static_assert(__has_rebind_other_v<_Tp, _Up>, "This allocator has to implement rebind");
using type _LIBCPP_NODEBUG = typename _Tp::template rebind<_Up>::other;
};
template <template <class, class...> class _Alloc, class _Tp, class... _Args, class _Up>
struct __allocator_traits_rebind<_Alloc<_Tp, _Args...>, _Up, true> {
using type _LIBCPP_NODEBUG = typename _Alloc<_Tp, _Args...>::template rebind<_Up>::other;
};
template <template <class, class...> class _Alloc, class _Tp, class... _Args, class _Up>
struct __allocator_traits_rebind<_Alloc<_Tp, _Args...>, _Up, false> {
using type _LIBCPP_NODEBUG = _Alloc<_Up, _Args...>;
};
_LIBCPP_SUPPRESS_DEPRECATED_POP
template <class _Alloc, class _Tp>
using __allocator_traits_rebind_t _LIBCPP_NODEBUG = typename __allocator_traits_rebind<_Alloc, _Tp>::type;
_LIBCPP_SUPPRESS_DEPRECATED_PUSH
// __has_allocate_hint_v
template <class _Alloc, class _SizeType, class _ConstVoidPtr, class = void>
inline const bool __has_allocate_hint_v = false;
template <class _Alloc, class _SizeType, class _ConstVoidPtr>
inline const bool __has_allocate_hint_v<
_Alloc,
_SizeType,
_ConstVoidPtr,
decltype((void)std::declval<_Alloc>().allocate(std::declval<_SizeType>(), std::declval<_ConstVoidPtr>()))> = true;
// __has_construct_v
template <class, class _Alloc, class... _Args>
inline const bool __has_construct_impl = false;
template <class _Alloc, class... _Args>
inline const bool
__has_construct_impl<decltype((void)std::declval<_Alloc>().construct(std::declval<_Args>()...)), _Alloc, _Args...> =
true;
template <class _Alloc, class... _Args>
inline const bool __has_construct_v = __has_construct_impl<void, _Alloc, _Args...>;
// __has_destroy_v
template <class _Alloc, class _Pointer, class = void>
inline const bool __has_destroy_v = false;
template <class _Alloc, class _Pointer>
inline const bool
__has_destroy_v<_Alloc, _Pointer, decltype((void)std::declval<_Alloc>().destroy(std::declval<_Pointer>()))> = true;
// __has_max_size_v
template <class _Alloc, class = void>
inline const bool __has_max_size_v = false;
template <class _Alloc>
inline const bool __has_max_size_v<_Alloc, decltype((void)std::declval<_Alloc&>().max_size())> = true;
// __has_select_on_container_copy_construction_v
template <class _Alloc, class = void>
inline const bool __has_select_on_container_copy_construction_v = false;
template <class _Alloc>
inline const bool __has_select_on_container_copy_construction_v<
_Alloc,
decltype((void)std::declval<_Alloc>().select_on_container_copy_construction())> = true;
_LIBCPP_SUPPRESS_DEPRECATED_POP
#if _LIBCPP_STD_VER >= 23
template <class _Pointer, class _SizeType = size_t>
struct allocation_result {
_Pointer ptr;
_SizeType count;
};
_LIBCPP_CTAD_SUPPORTED_FOR_TYPE(allocation_result);
#endif // _LIBCPP_STD_VER
template <class _Alloc>
struct allocator_traits {
using allocator_type = _Alloc;
using value_type = typename allocator_type::value_type;
using pointer = __pointer<value_type, allocator_type>;
using const_pointer = __const_pointer_t<value_type, pointer, allocator_type>;
using void_pointer = __void_pointer_t<pointer, allocator_type>;
using const_void_pointer = __const_void_pointer_t<pointer, allocator_type>;
using difference_type = typename __alloc_traits_difference_type<allocator_type, pointer>::type;
using size_type = __size_type<allocator_type, difference_type>;
using propagate_on_container_copy_assignment = __propagate_on_container_copy_assignment<allocator_type>;
using propagate_on_container_move_assignment = __propagate_on_container_move_assignment<allocator_type>;
using propagate_on_container_swap = __propagate_on_container_swap<allocator_type>;
using is_always_equal = __is_always_equal<allocator_type>;
#ifndef _LIBCPP_CXX03_LANG
template <class _Tp>
using rebind_alloc = __allocator_traits_rebind_t<allocator_type, _Tp>;
template <class _Tp>
using rebind_traits = allocator_traits<rebind_alloc<_Tp> >;
#else // _LIBCPP_CXX03_LANG
template <class _Tp>
struct rebind_alloc {
using other = __allocator_traits_rebind_t<allocator_type, _Tp>;
};
template <class _Tp>
struct rebind_traits {
using other = allocator_traits<typename rebind_alloc<_Tp>::other>;
};
#endif // _LIBCPP_CXX03_LANG
[[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 static pointer
allocate(allocator_type& __a, size_type __n) {
return __a.allocate(__n);
}
template <class _Ap = _Alloc, __enable_if_t<__has_allocate_hint_v<_Ap, size_type, const_void_pointer>, int> = 0>
[[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 static pointer
allocate(allocator_type& __a, size_type __n, const_void_pointer __hint) {
_LIBCPP_SUPPRESS_DEPRECATED_PUSH
return __a.allocate(__n, __hint);
_LIBCPP_SUPPRESS_DEPRECATED_POP
}
template <class _Ap = _Alloc, __enable_if_t<!__has_allocate_hint_v<_Ap, size_type, const_void_pointer>, int> = 0>
[[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 static pointer
allocate(allocator_type& __a, size_type __n, const_void_pointer) {
return __a.allocate(__n);
}
#if _LIBCPP_STD_VER >= 23
template <class _Ap = _Alloc>
[[nodiscard]] _LIBCPP_HIDE_FROM_ABI static constexpr allocation_result<pointer, size_type>
allocate_at_least(_Ap& __alloc, size_type __n) {
if constexpr (requires { __alloc.allocate_at_least(__n); }) {
return __alloc.allocate_at_least(__n);
} else {
return {__alloc.allocate(__n), __n};
}
}
#endif
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 static void
deallocate(allocator_type& __a, pointer __p, size_type __n) _NOEXCEPT {
__a.deallocate(__p, __n);
}
template <class _Tp, class... _Args, __enable_if_t<__has_construct_v<allocator_type, _Tp*, _Args...>, int> = 0>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 static void
construct(allocator_type& __a, _Tp* __p, _Args&&... __args) {
_LIBCPP_SUPPRESS_DEPRECATED_PUSH
__a.construct(__p, std::forward<_Args>(__args)...);
_LIBCPP_SUPPRESS_DEPRECATED_POP
}
template <class _Tp, class... _Args, __enable_if_t<!__has_construct_v<allocator_type, _Tp*, _Args...>, int> = 0>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 static void
construct(allocator_type&, _Tp* __p, _Args&&... __args) {
std::__construct_at(__p, std::forward<_Args>(__args)...);
}
template <class _Tp, __enable_if_t<__has_destroy_v<allocator_type, _Tp*>, int> = 0>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 static void destroy(allocator_type& __a, _Tp* __p) {
_LIBCPP_SUPPRESS_DEPRECATED_PUSH
__a.destroy(__p);
_LIBCPP_SUPPRESS_DEPRECATED_POP
}
template <class _Tp, __enable_if_t<!__has_destroy_v<allocator_type, _Tp*>, int> = 0>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 static void destroy(allocator_type&, _Tp* __p) {
std::__destroy_at(__p);
}
template <class _Ap = _Alloc, __enable_if_t<__has_max_size_v<const _Ap>, int> = 0>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 static size_type max_size(const allocator_type& __a) _NOEXCEPT {
_LIBCPP_SUPPRESS_DEPRECATED_PUSH
return __a.max_size();
_LIBCPP_SUPPRESS_DEPRECATED_POP
}
template <class _Ap = _Alloc, __enable_if_t<!__has_max_size_v<const _Ap>, int> = 0>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 static size_type max_size(const allocator_type&) _NOEXCEPT {
return numeric_limits<size_type>::max() / sizeof(value_type);
}
template <class _Ap = _Alloc, __enable_if_t<__has_select_on_container_copy_construction_v<const _Ap>, int> = 0>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 static allocator_type
select_on_container_copy_construction(const allocator_type& __a) {
return __a.select_on_container_copy_construction();
}
template <class _Ap = _Alloc, __enable_if_t<!__has_select_on_container_copy_construction_v<const _Ap>, int> = 0>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 static allocator_type
select_on_container_copy_construction(const allocator_type& __a) {
return __a;
}
};
#ifndef _LIBCPP_CXX03_LANG
template <class _Traits, class _Tp>
using __rebind_alloc _LIBCPP_NODEBUG = typename _Traits::template rebind_alloc<_Tp>;
#else
template <class _Traits, class _Tp>
using __rebind_alloc _LIBCPP_NODEBUG = typename _Traits::template rebind_alloc<_Tp>::other;
#endif
template <class _Alloc>
struct __check_valid_allocator : true_type {
using _Traits _LIBCPP_NODEBUG = std::allocator_traits<_Alloc>;
static_assert(is_same<_Alloc, __rebind_alloc<_Traits, typename _Traits::value_type> >::value,
"[allocator.requirements] states that rebinding an allocator to the same type should result in the "
"original allocator");
};
// __is_default_allocator_v
template <class _Tp>
inline const bool __is_std_allocator_v = false;
template <class _Tp>
inline const bool __is_std_allocator_v<allocator<_Tp> > = true;
// __is_cpp17_move_insertable_v
template <class _Alloc>
inline const bool __is_cpp17_move_insertable_v =
is_move_constructible<typename _Alloc::value_type>::value ||
(!__is_std_allocator_v<_Alloc> &&
__has_construct_v<_Alloc, typename _Alloc::value_type*, typename _Alloc::value_type&&>);
// __is_cpp17_copy_insertable_v
template <class _Alloc>
inline const bool __is_cpp17_copy_insertable_v =
__is_cpp17_move_insertable_v<_Alloc> &&
(is_copy_constructible<typename _Alloc::value_type>::value ||
(!__is_std_allocator_v<_Alloc> &&
__has_construct_v<_Alloc, typename _Alloc::value_type*, const typename _Alloc::value_type&>));
_LIBCPP_END_NAMESPACE_STD
_LIBCPP_POP_MACROS
#endif // _LIBCPP___MEMORY_ALLOCATOR_TRAITS_H