| // Copyright 2023 The Pigweed Authors |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); you may not |
| // use this file except in compliance with the License. You may obtain a copy of |
| // the License at |
| // |
| // https://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, WITHOUT |
| // WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the |
| // License for the specific language governing permissions and limitations under |
| // the License. |
| #pragma once |
| |
| #include "pw_polyfill/standard_library/namespace.h" |
| |
| _PW_POLYFILL_BEGIN_NAMESPACE_STD |
| |
| // NOT IMPLEMENTED: Some functions and overloads are missing. |
| template <typename T> |
| class char_traits { |
| public: |
| static constexpr void assign(T& dest, const T& source) noexcept { |
| dest = source; |
| } |
| |
| static constexpr T* assign(T* dest, decltype(sizeof(0)) count, T value) { |
| for (decltype(sizeof(0)) i = 0; i < count; ++i) { |
| dest[i] = value; |
| } |
| return dest; |
| } |
| |
| static constexpr bool eq(T lhs, T rhs) noexcept { return lhs == rhs; } |
| |
| static constexpr bool lt(T lhs, T rhs) noexcept { return lhs < rhs; } |
| |
| static constexpr T* move(T* dest, |
| const T* source, |
| decltype(sizeof(0)) count) { |
| if (dest < source) { |
| copy(dest, source, count); |
| } else if (source < dest) { |
| for (decltype(sizeof(0)) i = count; i != 0; --i) { |
| assign(dest[i - 1], source[i - 1]); |
| } |
| } |
| return dest; |
| } |
| |
| static constexpr T* copy(T* dest, |
| const T* source, |
| decltype(sizeof(0)) count) { |
| for (decltype(sizeof(0)) i = 0; i < count; ++i) { |
| char_traits<T>::assign(dest[i], source[i]); |
| } |
| return dest; |
| } |
| |
| static constexpr int compare(const T* lhs, |
| const T* rhs, |
| decltype(sizeof(0)) count) { |
| for (decltype(sizeof(0)) i = 0; i < count; ++i) { |
| if (!eq(lhs[i], rhs[i])) { |
| return lt(lhs[i], rhs[i]) ? -1 : 1; |
| } |
| } |
| return 0; |
| } |
| }; |
| |
| _PW_POLYFILL_END_NAMESPACE_STD |