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
20namespace 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