diff options
Diffstat (limited to 'third_party/abseil_cpp/absl/flags/commandlineflag.h')
| -rw-r--r-- | third_party/abseil_cpp/absl/flags/commandlineflag.h | 196 |
1 files changed, 0 insertions, 196 deletions
diff --git a/third_party/abseil_cpp/absl/flags/commandlineflag.h b/third_party/abseil_cpp/absl/flags/commandlineflag.h deleted file mode 100644 index 7e21d05d8a..0000000000 --- a/third_party/abseil_cpp/absl/flags/commandlineflag.h +++ /dev/null @@ -1,196 +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. -// -// ----------------------------------------------------------------------------- -// File: commandlineflag.h -// ----------------------------------------------------------------------------- -// -// This header file defines the `CommandLineFlag`, which acts as a type-erased -// handle for accessing metadata about the Abseil Flag in question. -// -// Because an actual Abseil flag is of an unspecified type, you should not -// manipulate or interact directly with objects of that type. Instead, use the -// CommandLineFlag type as an intermediary. -#ifndef ABSL_FLAGS_COMMANDLINEFLAG_H_ -#define ABSL_FLAGS_COMMANDLINEFLAG_H_ - -#include <memory> -#include <string> - -#include "absl/base/config.h" -#include "absl/base/internal/fast_type_id.h" -#include "absl/flags/internal/commandlineflag.h" -#include "absl/strings/string_view.h" -#include "absl/types/optional.h" - -namespace absl { -ABSL_NAMESPACE_BEGIN -namespace flags_internal { -class PrivateHandleAccessor; -} // namespace flags_internal - -// CommandLineFlag -// -// This type acts as a type-erased handle for an instance of an Abseil Flag and -// holds reflection information pertaining to that flag. Use CommandLineFlag to -// access a flag's name, location, help string etc. -// -// To obtain an absl::CommandLineFlag, invoke `absl::FindCommandLineFlag()` -// passing it the flag name string. -// -// Example: -// -// // Obtain reflection handle for a flag named "flagname". -// const absl::CommandLineFlag* my_flag_data = -// absl::FindCommandLineFlag("flagname"); -// -// // Now you can get flag info from that reflection handle. -// std::string flag_location = my_flag_data->Filename(); -// ... -class CommandLineFlag { - public: - constexpr CommandLineFlag() = default; - - // Not copyable/assignable. - CommandLineFlag(const CommandLineFlag&) = delete; - CommandLineFlag& operator=(const CommandLineFlag&) = delete; - - // absl::CommandLineFlag::IsOfType() - // - // Return true iff flag has type T. - template <typename T> - inline bool IsOfType() const { - return TypeId() == base_internal::FastTypeId<T>(); - } - - // absl::CommandLineFlag::TryGet() - // - // Attempts to retrieve the flag value. Returns value on success, - // absl::nullopt otherwise. - template <typename T> - absl::optional<T> TryGet() const { - if (IsRetired() || !IsOfType<T>()) { - return absl::nullopt; - } - - // Implementation notes: - // - // We are wrapping a union around the value of `T` to serve three purposes: - // - // 1. `U.value` has correct size and alignment for a value of type `T` - // 2. The `U.value` constructor is not invoked since U's constructor does - // not do it explicitly. - // 3. The `U.value` destructor is invoked since U's destructor does it - // explicitly. This makes `U` a kind of RAII wrapper around non default - // constructible value of T, which is destructed when we leave the - // scope. We do need to destroy U.value, which is constructed by - // CommandLineFlag::Read even though we left it in a moved-from state - // after std::move. - // - // All of this serves to avoid requiring `T` being default constructible. - union U { - T value; - U() {} - ~U() { value.~T(); } - }; - U u; - - Read(&u.value); - return std::move(u.value); - } - - // absl::CommandLineFlag::Name() - // - // Returns name of this flag. - virtual absl::string_view Name() const = 0; - - // absl::CommandLineFlag::Filename() - // - // Returns name of the file where this flag is defined. - virtual std::string Filename() const = 0; - - // absl::CommandLineFlag::Help() - // - // Returns help message associated with this flag. - virtual std::string Help() const = 0; - - // absl::CommandLineFlag::IsRetired() - // - // Returns true iff this object corresponds to retired flag. - virtual bool IsRetired() const; - - // absl::CommandLineFlag::DefaultValue() - // - // Returns the default value for this flag. - virtual std::string DefaultValue() const = 0; - - // absl::CommandLineFlag::CurrentValue() - // - // Returns the current value for this flag. - virtual std::string CurrentValue() const = 0; - - // absl::CommandLineFlag::ParseFrom() - // - // Sets the value of the flag based on specified string `value`. If the flag - // was successfully set to new value, it returns true. Otherwise, sets `error` - // to indicate the error, leaves the flag unchanged, and returns false. - bool ParseFrom(absl::string_view value, std::string* error); - - protected: - ~CommandLineFlag() = default; - - private: - friend class flags_internal::PrivateHandleAccessor; - - // Sets the value of the flag based on specified string `value`. If the flag - // was successfully set to new value, it returns true. Otherwise, sets `error` - // to indicate the error, leaves the flag unchanged, and returns false. There - // are three ways to set the flag's value: - // * Update the current flag value - // * Update the flag's default value - // * Update the current flag value if it was never set before - // The mode is selected based on `set_mode` parameter. - virtual bool ParseFrom(absl::string_view value, - flags_internal::FlagSettingMode set_mode, - flags_internal::ValueSource source, - std::string& error) = 0; - - // Returns id of the flag's value type. - virtual flags_internal::FlagFastTypeId TypeId() const = 0; - - // Interface to save flag to some persistent state. Returns current flag state - // or nullptr if flag does not support saving and restoring a state. - virtual std::unique_ptr<flags_internal::FlagStateInterface> SaveState() = 0; - - // Copy-construct a new value of the flag's type in a memory referenced by - // the dst based on the current flag's value. - virtual void Read(void* dst) const = 0; - - // To be deleted. Used to return true if flag's current value originated from - // command line. - virtual bool IsSpecifiedOnCommandLine() const = 0; - - // Validates supplied value usign validator or parseflag routine - virtual bool ValidateInputValue(absl::string_view value) const = 0; - - // Checks that flags default value can be converted to string and back to the - // flag's value type. - virtual void CheckDefaultValueParsingRoundtrip() const = 0; -}; - -ABSL_NAMESPACE_END -} // namespace absl - -#endif // ABSL_FLAGS_COMMANDLINEFLAG_H_ |