1 // Copyright 2020 The Pigweed Authors
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License"); you may not
4 // use this file except in compliance with the License. You may obtain a copy of
5 // the License at
6 //
7 // https://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
11 // WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
12 // License for the specific language governing permissions and limitations under
13 // the License.
14 #pragma once
15
16 #include <type_traits>
17
18 #include "pw_polyfill/standard_library/namespace.h"
19
20 _PW_POLYFILL_BEGIN_NAMESPACE_STD
21
22 template <typename T>
move(T && object)23 constexpr remove_reference_t<T>&& move(T&& object) {
24 return (remove_reference_t<T>&&)object;
25 }
26
27 template <typename T>
forward(remove_reference_t<T> & value)28 constexpr T&& forward(remove_reference_t<T>& value) {
29 return static_cast<T&&>(value);
30 }
31
32 template <typename T>
forward(remove_reference_t<T> && value)33 constexpr T&& forward(remove_reference_t<T>&& value) {
34 return static_cast<T&&>(value);
35 }
36
37 // Forward declare these classes, which are specialized in other headers.
38 template <decltype(sizeof(0)), typename>
39 struct tuple_element;
40
41 template <typename>
42 struct tuple_size;
43
44 template <typename T, T... kSequence>
45 class integer_sequence;
46
47 template <decltype(sizeof(0))... kSequence>
48 using index_sequence = integer_sequence<decltype(sizeof(0)), kSequence...>;
49
50 template <typename T, T kEnd>
51 #if __has_builtin(__make_integer_seq)
52 using make_integer_sequence = __make_integer_seq<integer_sequence, T, kEnd>;
53 #elif __has_builtin(__integer_pack)
54 using make_integer_sequence = integer_sequence<T, __integer_pack(kEnd)...>;
55 #endif // make_integer_sequence
56
57 template <decltype(sizeof(0)) kEnd>
58 using make_index_sequence = make_integer_sequence<decltype(sizeof(0)), kEnd>;
59
60 struct in_place_t {
61 explicit constexpr in_place_t() = default;
62 };
63
64 inline constexpr in_place_t in_place{};
65
66 _PW_POLYFILL_END_NAMESPACE_STD
67