91 lines
2.8 KiB
C++
91 lines
2.8 KiB
C++
//
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// Copyright 2020 The Abseil Authors.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// https://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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//
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// -----------------------------------------------------------------------------
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// File: reflection.h
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// -----------------------------------------------------------------------------
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//
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// This file defines the routines to access and operate on an Abseil Flag's
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// reflection handle.
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#ifndef ABSL_FLAGS_REFLECTION_H_
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#define ABSL_FLAGS_REFLECTION_H_
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#include <string>
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#include "absl/base/config.h"
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#include "absl/container/flat_hash_map.h"
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#include "absl/flags/commandlineflag.h"
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#include "absl/flags/internal/commandlineflag.h"
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namespace absl {
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ABSL_NAMESPACE_BEGIN
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namespace flags_internal {
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class FlagSaverImpl;
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} // namespace flags_internal
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// FindCommandLineFlag()
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//
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// Returns the reflection handle of an Abseil flag of the specified name, or
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// `nullptr` if not found. This function will emit a warning if the name of a
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// 'retired' flag is specified.
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absl::CommandLineFlag* FindCommandLineFlag(absl::string_view name);
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// Returns current state of the Flags registry in a form of mapping from flag
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// name to a flag reflection handle.
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absl::flat_hash_map<absl::string_view, absl::CommandLineFlag*> GetAllFlags();
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//------------------------------------------------------------------------------
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// FlagSaver
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//------------------------------------------------------------------------------
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//
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// A FlagSaver object stores the state of flags in the scope where the FlagSaver
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// is defined, allowing modification of those flags within that scope and
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// automatic restoration of the flags to their previous state upon leaving the
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// scope.
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//
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// A FlagSaver can be used within tests to temporarily change the test
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// environment and restore the test case to its previous state.
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//
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// Example:
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//
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// void MyFunc() {
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// absl::FlagSaver fs;
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// ...
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// absl::SetFlag(&FLAGS_myFlag, otherValue);
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// ...
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// } // scope of FlagSaver left, flags return to previous state
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//
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// This class is thread-safe.
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class FlagSaver {
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public:
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FlagSaver();
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~FlagSaver();
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FlagSaver(const FlagSaver&) = delete;
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void operator=(const FlagSaver&) = delete;
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private:
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flags_internal::FlagSaverImpl* impl_;
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};
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//-----------------------------------------------------------------------------
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ABSL_NAMESPACE_END
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} // namespace absl
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#endif // ABSL_FLAGS_REFLECTION_H_
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