| // 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 "lib/fit/function.h" |
| #include "pw_function/config.h" |
| |
| namespace pw { |
| |
| // pw::Function is a wrapper for an arbitrary 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 ElementsArePositive(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 Callable, |
| size_t inline_target_size = |
| function_internal::config::kInlineCallableSize> |
| using Function = fit::function_impl< |
| inline_target_size, |
| /*require_inline=*/!function_internal::config::kEnableDynamicAllocation, |
| Callable>; |
| |
| // Always inlined version of pw::Function. |
| // |
| // IMPORTANT: If pw::Function is configured to allow dynamic allocations then |
| // any attempt to convert `pw::InlineFunction` to `pw::Function` will ALWAYS |
| // allocate. |
| // |
| // TODO(b/252852651): Remove warning above when conversion from |
| // fit::inline_function to fit::function doesn't allocate anymore. |
| template <typename Callable, |
| size_t inline_target_size = |
| function_internal::config::kInlineCallableSize> |
| using InlineFunction = fit::inline_function<Callable, inline_target_size>; |
| |
| using Closure = Function<void()>; |
| |
| // pw::Callback is identical to pw::Function except: |
| // |
| // 1) On the first call to invoke a `pw::Callback`, the target function held |
| // by the `pw::Callback` cannot be called again. |
| // 2) When a `pw::Callback` is invoked for the first time, the target function |
| // is released and destructed, along with any resources owned by that |
| // function (typically the objects captured by a lambda). |
| |
| // A `pw::Callback` in the "already called" state has the same state as a |
| // `pw::Callback` that has been assigned to `nullptr`. |
| template <typename Callable, |
| size_t inline_target_size = |
| function_internal::config::kInlineCallableSize> |
| using Callback = fit::callback_impl< |
| inline_target_size, |
| /*require_inline=*/!function_internal::config::kEnableDynamicAllocation, |
| Callable>; |
| |
| template <typename Callable, |
| size_t inline_target_size = |
| function_internal::config::kInlineCallableSize> |
| using InlineCallback = fit::inline_callback<Callable, inline_target_size>; |
| |
| } // namespace pw |