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Diffstat (limited to 'third_party/abseil_cpp/absl/base/internal/fast_type_id.h')
-rw-r--r-- | third_party/abseil_cpp/absl/base/internal/fast_type_id.h | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/third_party/abseil_cpp/absl/base/internal/fast_type_id.h b/third_party/abseil_cpp/absl/base/internal/fast_type_id.h new file mode 100644 index 000000000000..3db59e83745b --- /dev/null +++ b/third_party/abseil_cpp/absl/base/internal/fast_type_id.h @@ -0,0 +1,48 @@ +// +// Copyright 2020 The Abseil 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. +// + +#ifndef ABSL_BASE_INTERNAL_FAST_TYPE_ID_H_ +#define ABSL_BASE_INTERNAL_FAST_TYPE_ID_H_ + +#include "absl/base/config.h" + +namespace absl { +ABSL_NAMESPACE_BEGIN +namespace base_internal { + +template <typename Type> +struct FastTypeTag { + constexpr static char dummy_var = 0; +}; + +template <typename Type> +constexpr char FastTypeTag<Type>::dummy_var; + +// FastTypeId<Type>() evaluates at compile/link-time to a unique pointer for the +// passed-in type. These are meant to be good match for keys into maps or +// straight up comparisons. +using FastTypeIdType = const void*; + +template <typename Type> +constexpr inline FastTypeIdType FastTypeId() { + return &FastTypeTag<Type>::dummy_var; +} + +} // namespace base_internal +ABSL_NAMESPACE_END +} // namespace absl + +#endif // ABSL_BASE_INTERNAL_FAST_TYPE_ID_H_ |