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 <array>
17 #include <type_traits>
18 #include <utility>
19
20 #include "pw_polyfill/standard_library/namespace.h"
21
22 #ifndef __cpp_lib_to_array
23 #define __cpp_lib_to_array 201907L
24
25 _PW_POLYFILL_BEGIN_NAMESPACE_STD
26
27 namespace impl {
28
29 template <typename T, size_t size, size_t... indices>
CopyArray(const T (& values)[size],index_sequence<indices...>)30 constexpr array<remove_cv_t<T>, size> CopyArray(const T (&values)[size],
31 index_sequence<indices...>) {
32 return {{values[indices]...}};
33 }
34
35 template <typename T, size_t size, size_t... indices>
36 constexpr array<remove_cv_t<T>, size> MoveArray(T(&&values)[size],
37 index_sequence<indices...>) {
38 return {{move(values[indices])...}};
39 }
40
41 } // namespace impl
42
43 template <typename T, size_t size>
to_array(T (& values)[size])44 constexpr array<remove_cv_t<T>, size> to_array(T (&values)[size]) {
45 return impl::CopyArray(values, make_index_sequence<size>{});
46 }
47
48 template <typename T, size_t size>
49 constexpr array<remove_cv_t<T>, size> to_array(T(&&values)[size]) {
50 return impl::MoveArray(move(values), make_index_sequence<size>{});
51 }
52
53 _PW_POLYFILL_END_NAMESPACE_STD
54
55 #endif // __cpp_lib_to_array
56