1 | // Copyright 2019 The Marl Authors. |
2 | // |
3 | // Licensed under the Apache License, Version 2.0 (the "License"); |
4 | // you may not use this file except in compliance with the License. |
5 | // You may obtain a copy of the License at |
6 | // |
7 | // https://www.apache.org/licenses/LICENSE-2.0 |
8 | // |
9 | // Unless required by applicable law or agreed to in writing, software |
10 | // distributed under the License is distributed on an "AS IS" BASIS, |
11 | // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
12 | // See the License for the specific language governing permissions and |
13 | // limitations under the License. |
14 | |
15 | #ifndef marl_defer_h |
16 | #define marl_defer_h |
17 | |
18 | #include "finally.h" |
19 | |
20 | namespace marl { |
21 | |
22 | #define MARL_CONCAT_(a, b) a##b |
23 | #define MARL_CONCAT(a, b) MARL_CONCAT_(a, b) |
24 | |
25 | // defer() is a macro to defer execution of a statement until the surrounding |
26 | // scope is closed and is typically used to perform cleanup logic once a |
27 | // function returns. |
28 | // |
29 | // Note: Unlike golang's defer(), the defer statement is executed when the |
30 | // surrounding *scope* is closed, not necessarily the function. |
31 | // |
32 | // Example usage: |
33 | // |
34 | // void sayHelloWorld() |
35 | // { |
36 | // defer(printf("world\n")); |
37 | // printf("hello "); |
38 | // } |
39 | // |
40 | #define defer(x) \ |
41 | auto MARL_CONCAT(defer_, __LINE__) = marl::make_finally([&] { x; }) |
42 | |
43 | } // namespace marl |
44 | |
45 | #endif // marl_defer_h |
46 | |