| // Copyright 2021 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_function/internal/function.h" |
| |
| namespace pw { |
| |
| // pw::Function is a wrapper for an aribtrary callable object. It can be used by |
| // callback-based APIs to allow callers to provide any type of callable. |
| // |
| // Example: |
| // |
| // template <typename T> |
| // bool All(const pw::Vector<T>& items, |
| // pw::Function<bool(const T& item)> predicate) { |
| // for (const T& item : items) { |
| // if (!predicate(item)) { |
| // return false; |
| // } |
| // } |
| // return true; |
| // } |
| // |
| // bool ElementsArePostive(const pw::Vector<int>& items) { |
| // return All(items, [](const int& i) { return i > 0; }); |
| // } |
| // |
| // bool IsEven(const int& i) { return i % 2 == 0; } |
| // |
| // bool ElementsAreEven(const pw::Vector<int>& items) { |
| // return All(items, IsEven); |
| // } |
| // |
| template <typename T> |
| using Function = function_internal::Function<T>; |
| |
| // A Closure is a function that does not take any arguments and returns nothing. |
| using Closure = Function<void()>; |
| |
| // nullptr comparisions for functions. |
| template <typename T> |
| bool operator==(const Function<T>& f, std::nullptr_t) { |
| return !f; |
| } |
| |
| template <typename T> |
| bool operator!=(const Function<T>& f, std::nullptr_t) { |
| return !!f; |
| } |
| |
| template <typename T> |
| bool operator==(std::nullptr_t, const Function<T>& f) { |
| return !f; |
| } |
| |
| template <typename T> |
| bool operator!=(std::nullptr_t, const Function<T>& f) { |
| return !!f; |
| } |
| |
| } // namespace pw |