xref: /openbsd-src/gnu/llvm/libcxx/include/experimental/__memory (revision c1a45aed656e7d5627c30c92421893a76f370ccb)
1// -*- C++ -*-
2//===----------------------------------------------------------------------===//
3//
4// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5// See https://llvm.org/LICENSE.txt for license information.
6// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7//
8//===----------------------------------------------------------------------===//
9
10#ifndef _LIBCPP_EXPERIMENTAL___MEMORY
11#define _LIBCPP_EXPERIMENTAL___MEMORY
12
13#include <__memory/allocator_arg_t.h>
14#include <__memory/uses_allocator.h>
15#include <experimental/__config>
16#include <experimental/utility> // for erased_type
17#include <__functional_base>
18#include <type_traits>
19
20_LIBCPP_BEGIN_NAMESPACE_LFTS
21
22template <
23    class _Tp, class _Alloc
24  , bool = uses_allocator<_Tp, _Alloc>::value
25  , bool = __has_allocator_type<_Tp>::value
26  >
27struct __lfts_uses_allocator : public false_type {};
28
29template <class _Tp, class _Alloc>
30struct __lfts_uses_allocator<_Tp, _Alloc, false, false> : public false_type {};
31
32template <class _Tp, class _Alloc, bool HasAlloc>
33struct __lfts_uses_allocator<_Tp, _Alloc, true, HasAlloc> : public true_type {};
34
35template <class _Tp, class _Alloc>
36struct __lfts_uses_allocator<_Tp, _Alloc, false, true>
37  : public integral_constant<bool
38    , is_convertible<_Alloc, typename _Tp::allocator_type>::value
39      || is_same<erased_type, typename _Tp::allocator_type>::value
40    >
41{};
42
43template <bool _UsesAlloc, class _Tp, class _Alloc, class ..._Args>
44struct __lfts_uses_alloc_ctor_imp
45{
46    static const int value = 0;
47};
48
49template <class _Tp, class _Alloc, class ..._Args>
50struct __lfts_uses_alloc_ctor_imp<true, _Tp, _Alloc, _Args...>
51{
52    static const bool __ic_first
53        = is_constructible<_Tp, allocator_arg_t, _Alloc, _Args...>::value;
54
55    static const bool __ic_second =
56        conditional<
57            __ic_first,
58            false_type,
59            is_constructible<_Tp, _Args..., _Alloc>
60        >::type::value;
61
62    static_assert(__ic_first || __ic_second,
63                  "Request for uses allocator construction is ill-formed");
64
65    static const int value = __ic_first ? 1 : 2;
66};
67
68template <class _Tp, class _Alloc, class ..._Args>
69struct __lfts_uses_alloc_ctor
70  : integral_constant<int,
71        __lfts_uses_alloc_ctor_imp<
72            __lfts_uses_allocator<_Tp, _Alloc>::value
73          , _Tp, _Alloc, _Args...
74        >::value
75    >
76{};
77
78template <class _Tp, class _Allocator, class... _Args>
79inline _LIBCPP_INLINE_VISIBILITY
80void __user_alloc_construct_impl (integral_constant<int, 0>, _Tp *__storage, const _Allocator &, _Args &&... __args )
81{
82    new (__storage) _Tp (_VSTD::forward<_Args>(__args)...);
83}
84
85// FIXME: This should have a version which takes a non-const alloc.
86template <class _Tp, class _Allocator, class... _Args>
87inline _LIBCPP_INLINE_VISIBILITY
88void __user_alloc_construct_impl (integral_constant<int, 1>, _Tp *__storage, const _Allocator &__a, _Args &&... __args )
89{
90    new (__storage) _Tp (allocator_arg, __a, _VSTD::forward<_Args>(__args)...);
91}
92
93// FIXME: This should have a version which takes a non-const alloc.
94template <class _Tp, class _Allocator, class... _Args>
95inline _LIBCPP_INLINE_VISIBILITY
96void __user_alloc_construct_impl (integral_constant<int, 2>, _Tp *__storage, const _Allocator &__a, _Args &&... __args )
97{
98    new (__storage) _Tp (_VSTD::forward<_Args>(__args)..., __a);
99}
100
101template <class _Tp, class _Alloc, class ..._Args>
102inline _LIBCPP_INLINE_VISIBILITY
103void __lfts_user_alloc_construct(
104    _Tp * __store, const _Alloc & __a, _Args &&... __args)
105{
106    ::std::experimental::fundamentals_v1::__user_alloc_construct_impl(
107        typename __lfts_uses_alloc_ctor<_Tp, _Alloc, _Args...>::type()
108       , __store, __a, _VSTD::forward<_Args>(__args)...
109       );
110}
111
112_LIBCPP_END_NAMESPACE_LFTS
113
114#endif /* _LIBCPP_EXPERIMENTAL___MEMORY */
115