1 // Uses-allocator Construction -*- C++ -*-
3 // Copyright (C) 2010-2016 Free Software Foundation, Inc.
5 // This file is part of the GNU ISO C++ Library. This library is free
6 // software; you can redistribute it and/or modify it under the
7 // terms of the GNU General Public License as published by the
8 // Free Software Foundation; either version 3, or (at your option)
11 // This library is distributed in the hope that it will be useful,
12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 // GNU General Public License for more details.
16 // Under Section 7 of GPL version 3, you are granted additional
17 // permissions described in the GCC Runtime Library Exception, version
18 // 3.1, as published by the Free Software Foundation.
20 // You should have received a copy of the GNU General Public License and
21 // a copy of the GCC Runtime Library Exception along with this program;
22 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23 // <http://www.gnu.org/licenses/>.
25 #ifndef _USES_ALLOCATOR_H
26 #define _USES_ALLOCATOR_H 1
28 #if __cplusplus < 201103L
29 # include <bits/c++0x_warning.h>
32 #include <type_traits>
33 #include <bits/move.h>
35 namespace std
_GLIBCXX_VISIBILITY(default)
37 _GLIBCXX_BEGIN_NAMESPACE_VERSION
39 struct __erased_type
{ };
41 template<typename _Alloc
, typename _Tp
>
42 using __is_erased_or_convertible
43 = __or_
<is_same
<_Tp
, __erased_type
>, is_convertible
<_Alloc
, _Tp
>>;
46 struct allocator_arg_t
{ explicit allocator_arg_t() = default; };
48 constexpr allocator_arg_t allocator_arg
= allocator_arg_t();
50 template<typename _Tp
, typename _Alloc
, typename
= __void_t
<>>
51 struct __uses_allocator_helper
54 template<typename _Tp
, typename _Alloc
>
55 struct __uses_allocator_helper
<_Tp
, _Alloc
,
56 __void_t
<typename
_Tp::allocator_type
>>
57 : __is_erased_or_convertible
<_Alloc
, typename
_Tp::allocator_type
>::type
60 /// [allocator.uses.trait]
61 template<typename _Tp
, typename _Alloc
>
63 : __uses_allocator_helper
<_Tp
, _Alloc
>::type
66 struct __uses_alloc_base
{ };
68 struct __uses_alloc0
: __uses_alloc_base
70 struct _Sink
{ void operator=(const void*) { } } _M_a
;
73 template<typename _Alloc
>
74 struct __uses_alloc1
: __uses_alloc_base
{ const _Alloc
* _M_a
; };
76 template<typename _Alloc
>
77 struct __uses_alloc2
: __uses_alloc_base
{ const _Alloc
* _M_a
; };
79 template<bool, typename _Tp
, typename _Alloc
, typename
... _Args
>
82 template<typename _Tp
, typename _Alloc
, typename
... _Args
>
83 struct __uses_alloc
<true, _Tp
, _Alloc
, _Args
...>
85 is_constructible
<_Tp
, allocator_arg_t
, _Alloc
, _Args
...>::value
,
86 __uses_alloc1
<_Alloc
>,
87 __uses_alloc2
<_Alloc
>>::type
90 is_constructible
<_Tp
, allocator_arg_t
, _Alloc
, _Args
...>,
91 is_constructible
<_Tp
, _Args
..., _Alloc
>>::value
, "construction with"
92 " an allocator must be possible if uses_allocator is true");
95 template<typename _Tp
, typename _Alloc
, typename
... _Args
>
96 struct __uses_alloc
<false, _Tp
, _Alloc
, _Args
...>
99 template<typename _Tp
, typename _Alloc
, typename
... _Args
>
100 using __uses_alloc_t
=
101 __uses_alloc
<uses_allocator
<_Tp
, _Alloc
>::value
, _Tp
, _Alloc
, _Args
...>;
103 template<typename _Tp
, typename _Alloc
, typename
... _Args
>
104 inline __uses_alloc_t
<_Tp
, _Alloc
, _Args
...>
105 __use_alloc(const _Alloc
& __a
)
107 __uses_alloc_t
<_Tp
, _Alloc
, _Args
...> __ret
;
108 __ret
._M_a
= std::__addressof(__a
);
112 _GLIBCXX_END_NAMESPACE_VERSION