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Diffstat (limited to 'third_party/abseil_cpp/absl/strings/internal/string_constant.h')
-rw-r--r-- | third_party/abseil_cpp/absl/strings/internal/string_constant.h | 70 |
1 files changed, 0 insertions, 70 deletions
diff --git a/third_party/abseil_cpp/absl/strings/internal/string_constant.h b/third_party/abseil_cpp/absl/strings/internal/string_constant.h deleted file mode 100644 index b15f1d9bcfac..000000000000 --- a/third_party/abseil_cpp/absl/strings/internal/string_constant.h +++ /dev/null @@ -1,70 +0,0 @@ -// 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_STRINGS_INTERNAL_STRING_CONSTANT_H_ -#define ABSL_STRINGS_INTERNAL_STRING_CONSTANT_H_ - -#include "absl/meta/type_traits.h" -#include "absl/strings/string_view.h" - -namespace absl { -ABSL_NAMESPACE_BEGIN -namespace strings_internal { - -// StringConstant<T> represents a compile time string constant. -// It can be accessed via its `absl::string_view value` static member. -// It is guaranteed that the `string_view` returned has constant `.data()`, -// constant `.size()` and constant `value[i]` for all `0 <= i < .size()` -// -// The `T` is an opaque type. It is guaranteed that different string constants -// will have different values of `T`. This allows users to associate the string -// constant with other static state at compile time. -// -// Instances should be made using the `MakeStringConstant()` factory function -// below. -template <typename T> -struct StringConstant { - private: - // Returns true if `view` points to constant data. - // Otherwise, it can't be constant evaluated. - static constexpr bool ValidateConstant(absl::string_view view) { - return view.empty() || 2 * view[0] != 1; - } - - public: - static constexpr absl::string_view value = T{}(); - constexpr absl::string_view operator()() const { return value; } - - static_assert(ValidateConstant(value), - "The input string_view must point to constant data."); -}; - -template <typename T> -constexpr absl::string_view StringConstant<T>::value; // NOLINT - -// Factory function for `StringConstant` instances. -// It supports callables that have a constexpr default constructor and a -// constexpr operator(). -// It must return an `absl::string_view` or `const char*` pointing to constant -// data. This is validated at compile time. -template <typename T> -constexpr StringConstant<T> MakeStringConstant(T) { - return {}; -} - -} // namespace strings_internal -ABSL_NAMESPACE_END -} // namespace absl - -#endif // ABSL_STRINGS_INTERNAL_STRING_CONSTANT_H_ |