| // Copyright 2015 The Cobalt Authors. 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_BASE_UNUSED_H_ |
| #define COBALT_BASE_UNUSED_H_ |
| |
| namespace base { |
| |
| // This struct is available for cases where a type is required, but will not be |
| // used, and causes the type to use 0 bytes. A current use case for this is with |
| // base::small_map. Because base::SmallSet does not exist, a map must sometimes |
| // be used in cases where the desired functionality is that of a set. Providing |
| // Unused as the map's value type allows the value to not add additional memory |
| // overhead. |
| struct Unused {}; |
| |
| } // namespace base |
| |
| #endif // COBALT_BASE_UNUSED_H_ |
