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 <iterator>
17 
18 #include "pw_polyfill/standard_library/namespace.h"
19 
20 // Define std::data and std::size.
21 #ifndef __cpp_lib_nonmember_container_access
22 #define __cpp_lib_nonmember_container_access 201411L
23 
24 #include <cstddef>
25 
26 _PW_POLYFILL_BEGIN_NAMESPACE_STD
27 
28 template <typename C>
29 constexpr auto data(C& container) -> decltype(container.data()) {
30   return container.data();
31 }
32 
33 template <typename C>
34 constexpr auto data(const C& container) -> decltype(container.data()) {
35   return container.data();
36 }
37 
38 template <typename T, size_t kSize>
data(T (& array)[kSize])39 constexpr T* data(T (&array)[kSize]) noexcept {
40   return array;
41 }
42 
43 template <typename C>
44 constexpr auto size(const C& container) -> decltype(container.size()) {
45   return container.size();
46 }
47 
48 template <typename T, size_t kSize>
size(const T (&)[kSize])49 constexpr size_t size(const T (&)[kSize]) noexcept {
50   return kSize;
51 }
52 
53 _PW_POLYFILL_END_NAMESPACE_STD
54 
55 #endif  // __cpp_lib_nonmember_container_access
56