1 /*
2  * Copyright (C) 2021 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #ifndef INCLUDE_PERFETTO_TRACING_TRACED_VALUE_FORWARD_H_
18 #define INCLUDE_PERFETTO_TRACING_TRACED_VALUE_FORWARD_H_
19 
20 namespace perfetto {
21 
22 class TracedValue;
23 class TracedArray;
24 class TracedDictionary;
25 
26 template <typename T>
27 void WriteIntoTracedValue(TracedValue context, T&& value);
28 
29 template <typename T, class = void>
30 struct TraceFormatTraits;
31 
32 // Write support checker to allow it to be used when matching.
33 //
34 // Intended to be used for types like smart pointers, who should support
35 // AsTracedValueInto only iff their inner type supports being written into
36 // a TracedValue.
37 //
38 // template <typename T>
39 // class SmartPtr {
40 //   ...
41 //
42 //   typename check_traced_value_support<T, void>::value
43 //   AsTracedValueInto(perfetto::TracedValue context) const {
44 //      WriteIntoTracedValue(std::move(context), *ptr_);
45 //   }
46 // };
47 template <typename T, typename ResultType = void, class = void>
48 struct check_traced_value_support;
49 
50 }  // namespace perfetto
51 
52 #endif  // INCLUDE_PERFETTO_TRACING_TRACED_VALUE_FORWARD_H_
53