| // Copyright 2015 Google Inc. All Rights Reserved. |
| // |
| // 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 |
| // |
| // http://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. |
| |
| #ifndef COBALT_RENDER_TREE_MOVABLE_H_ |
| #define COBALT_RENDER_TREE_MOVABLE_H_ |
| |
| // Defines a helper structure and Pass() method that can be used to express |
| // that we are passing the structure with move semantics and not copy semantics. |
| // This would be trivial in C++11. It should be passed directly into a |
| // constructor or object that will consume a moved object. |
| // It is different than what is found within base/move.h because this does |
| // not restrict one from also copying the object, and it also makes no attempt |
| // to automatically detect when the host object is being used as an rvalue, |
| // it must always be made explicit by calling Pass(). |
| #define DECLARE_AS_MOVABLE(x) \ |
| class Moved { \ |
| public: \ |
| explicit Moved(x* object) : object_(object) {} \ |
| x* operator*() { return object_; } \ |
| x* operator->() { return object_; } \ |
| \ |
| private: \ |
| x* object_; \ |
| }; \ |
| \ |
| Moved Pass() { return Moved(this); } |
| |
| #endif // COBALT_RENDER_TREE_MOVABLE_H_ |