identity.h 1.1 KB

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  1. // Copyright 2017 The Abseil Authors.
  2. //
  3. // Licensed under the Apache License, Version 2.0 (the "License");
  4. // you may not use this file except in compliance with the License.
  5. // You may obtain a copy of the License at
  6. //
  7. // https://www.apache.org/licenses/LICENSE-2.0
  8. //
  9. // Unless required by applicable law or agreed to in writing, software
  10. // distributed under the License is distributed on an "AS IS" BASIS,
  11. // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12. // See the License for the specific language governing permissions and
  13. // limitations under the License.
  14. //
  15. #ifndef ABSL_BASE_INTERNAL_IDENTITY_H_
  16. #define ABSL_BASE_INTERNAL_IDENTITY_H_
  17. #include "absl/base/config.h"
  18. namespace absl {
  19. ABSL_NAMESPACE_BEGIN
  20. namespace internal {
  21. // This is a back-fill of C++20's `std::type_identity`.
  22. template <typename T>
  23. struct type_identity {
  24. typedef T type;
  25. };
  26. // This is a back-fill of C++20's `std::type_identity_t`.
  27. template <typename T>
  28. using type_identity_t = typename type_identity<T>::type;
  29. } // namespace internal
  30. ABSL_NAMESPACE_END
  31. } // namespace absl
  32. #endif // ABSL_BASE_INTERNAL_IDENTITY_H_