| // Copyright 2022 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 <memory> |
| #include <type_traits> |
| |
| namespace pw::bluetooth::internal { |
| |
| // Helper deleter struct to call the OnDestroy template parameter method when |
| // RaiiPtr<Api, OnDestroy> is destroyed. |
| template <class Api, void (Api::*OnDestroy)()> |
| struct RaiiPtrDeleter { |
| void operator()(Api* api) { (api->*OnDestroy)(); } |
| }; |
| |
| // Smart pointer class to expose an API with RAII semantics that calls a |
| // specific method of the API implementation when it is destroyed, instead of |
| // calling delete on the API object like the default std::unique_ptr deleter |
| // behavior. This allows to be used like if it was a std::unique_ptr<API> but |
| // leaving the memory management implementation details up to the backend |
| // implementing the API. |
| // |
| // Example usage: |
| // class SomeApi { |
| // public: |
| // virtual ~SomeApi() = default; |
| // |
| // virtual void MethodOne() = 0; |
| // virtual void MethodTwo(int) = 0; |
| // |
| // private: |
| // // Method used to release the resource in the backend. |
| // virtual void DeleteResource() = 0; |
| // |
| // public: |
| // using Ptr = RaiiPtr<SomeApi, &SomeApi::DeleteResource>; |
| // }; |
| // |
| // // The concrete backend implementation. |
| // class BackendImplementation final : public SomeApi { |
| // public: |
| // void MethodOne() override { ... } |
| // void MethodTwo(int) override { ... } |
| // void DeleteResource() override { ... } |
| // }; |
| // |
| // // Example using a static global resource object. GetResource should check |
| // // whether the global resource is in use. |
| // BackendImplementation backend_impl; |
| // SomeApi::Ptr GetResource() { ...; return &backend_impl; } |
| // |
| template <class Api, void (Api::*OnDestroy)()> |
| using RaiiPtr = std::unique_ptr<Api, RaiiPtrDeleter<Api, OnDestroy>>; |
| |
| } // namespace pw::bluetooth::internal |
