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
22template <typename T>
23constexpr remove_reference_t<T>&& move(T&& object) {
24  return (remove_reference_t<T>&&)object;
25}
26
27template <typename T>
28constexpr T&& forward(remove_reference_t<T>& value) {
29  return static_cast<T&&>(value);
30}
31
32template <typename T>
33constexpr 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.
38template <decltype(sizeof(0)), typename>
39struct tuple_element;
40
41template <typename>
42struct tuple_size;
43
44template <typename T, T... kSequence>
45class integer_sequence;
46
47template <decltype(sizeof(0))... kSequence>
48using index_sequence = integer_sequence<decltype(sizeof(0)), kSequence...>;
49
50template <typename T, T kEnd>
51#if __has_builtin(__make_integer_seq)
52using make_integer_sequence = __make_integer_seq<integer_sequence, T, kEnd>;
53#elif __has_builtin(__integer_pack)
54using make_integer_sequence = integer_sequence<T, __integer_pack(kEnd)...>;
55#endif  // make_integer_sequence
56
57template <decltype(sizeof(0)) kEnd>
58using make_index_sequence = make_integer_sequence<decltype(sizeof(0)), kEnd>;
59
60struct in_place_t {
61  explicit constexpr in_place_t() = default;
62};
63
64inline constexpr in_place_t in_place{};
65
66_PW_POLYFILL_END_NAMESPACE_STD
67