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
69
70
71
72
73
74
75
76
77
|
/**
* \file libipc/scope_exit.h
* \author mutouyun (orz@orzz.org)
* \brief Execute guard function when the enclosing scope exits.
*/
#pragma once
#include <utility> // std::forward, std::move
#include <functional> // std::function
#include <type_traits>
#include "libipc/imp/detect_plat.h"
namespace ipc {
template <typename F = std::function<void()>>
class scope_exit {
F destructor_;
mutable bool released_;
public:
template <typename G>
explicit scope_exit(G &&destructor) noexcept
: destructor_(std::forward<G>(destructor))
, released_ (false) {}
scope_exit(scope_exit &&other) noexcept
: destructor_(std::move(other.destructor_))
, released_ (std::exchange(other.released_, true)) /*release rhs*/ {}
scope_exit &operator=(scope_exit &&other) noexcept {
destructor_ = std::move(other.destructor_);
released_ = std::exchange(other.released_, true);
return *this;
}
~scope_exit() noexcept {
if (!released_) destructor_();
}
void release() const noexcept {
released_ = true;
}
void do_exit() noexcept {
if (released_) return;
destructor_();
released_ = true;
}
void swap(scope_exit &other) noexcept {
std::swap(destructor_, other.destructor_);
std::swap(released_ , other.released_);
}
};
/// \brief Creates a scope_exit object.
template <typename F>
auto make_scope_exit(F &&destructor) noexcept {
return scope_exit<std::decay_t<F>>(std::forward<F>(destructor));
}
namespace detail_scope_exit {
struct scope_exit_helper {
template <typename F>
auto operator=(F &&f) const noexcept {
return make_scope_exit(std::forward<F>(f));
}
};
} // namespace detail_scope_exit
#define LIBIPC_SCOPE_EXIT($VAL) \
LIBIPC_UNUSED auto $VAL = ::ipc::detail_scope_exit::scope_exit_helper{}
} // namespace ipc
|
