67 lines
2.1 KiB
C
67 lines
2.1 KiB
C
|
//
|
||
|
|
// Copyright 2019 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: declare.h
|
||
|
|
// -----------------------------------------------------------------------------
|
||
|
|
//
|
||
|
|
// This file defines the ABSL_DECLARE_FLAG macro, allowing you to declare an
|
||
|
|
// `absl::Flag` for use within a translation unit. You should place this
|
||
|
|
// declaration within the header file associated with the .cc file that defines
|
||
|
|
// and owns the `Flag`.
|
||
|
|
|
||
|
|
#ifndef ABSL_FLAGS_DECLARE_H_
|
||
|
|
#define ABSL_FLAGS_DECLARE_H_
|
||
|
|
|
||
|
|
#include "absl/base/config.h"
|
||
|
|
#include "absl/strings/string_view.h"
|
||
|
|
|
||
|
|
namespace absl {
|
||
|
|
ABSL_NAMESPACE_BEGIN
|
||
|
|
namespace flags_internal {
|
||
|
|
|
||
|
|
// absl::Flag<T> represents a flag of type 'T' created by ABSL_FLAG.
|
||
|
|
template <typename T>
|
||
|
|
class Flag;
|
||
|
|
|
||
|
|
} // namespace flags_internal
|
||
|
|
|
||
|
|
// Flag
|
||
|
|
//
|
||
|
|
// Forward declaration of the `absl::Flag` type for use in defining the macro.
|
||
|
|
#if defined(_MSC_VER) && !defined(__clang__)
|
||
|
|
template <typename T>
|
||
|
|
class Flag;
|
||
|
|
#else
|
||
|
|
template <typename T>
|
||
|
|
using Flag = flags_internal::Flag<T>;
|
||
|
|
#endif
|
||
|
|
|
||
|
|
ABSL_NAMESPACE_END
|
||
|
|
} // namespace absl
|
||
|
|
|
||
|
|
// ABSL_DECLARE_FLAG()
|
||
|
|
//
|
||
|
|
// This macro is a convenience for declaring use of an `absl::Flag` within a
|
||
|
|
// translation unit. This macro should be used within a header file to
|
||
|
|
// declare usage of the flag within any .cc file including that header file.
|
||
|
|
//
|
||
|
|
// The ABSL_DECLARE_FLAG(type, name) macro expands to:
|
||
|
|
//
|
||
|
|
// extern absl::Flag<type> FLAGS_name;
|
||
|
|
#define ABSL_DECLARE_FLAG(type, name) extern ::absl::Flag<type> FLAGS_##name
|
||
|
|
|
||
|
|
#endif // ABSL_FLAGS_DECLARE_H_
|