blob: 8d2a856e3b06901d2f16f5fb6b90f9b3d6963543 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
|
//
// 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"
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.
template <typename T>
using Flag = flags_internal::Flag<T>;
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) ABSL_DECLARE_FLAG_INTERNAL(type, name)
// Internal implementation of ABSL_DECLARE_FLAG to allow macro expansion of its
// arguments. Clients must use ABSL_DECLARE_FLAG instead.
#define ABSL_DECLARE_FLAG_INTERNAL(type, name) \
extern absl::Flag<type> FLAGS_##name; \
namespace absl /* block flags in namespaces */ {} \
/* second redeclaration is to allow applying attributes */ \
extern absl::Flag<type> FLAGS_##name
#endif // ABSL_FLAGS_DECLARE_H_
|
