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
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
|
/*
* Copyright 2016, The libsigc++ Development Team
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#ifndef SIGC_WEAK_RAW_PTR_HPP
#define SIGC_WEAK_RAW_PTR_HPP
#include <sigc++/trackable.h> //Just for notifiable.
namespace sigc
{
struct notifiable;
namespace internal
{
/** T must derive from sigc::trackable.
*/
template<typename T>
struct weak_raw_ptr : public sigc::notifiable
{
inline weak_raw_ptr() : p_(nullptr) {}
inline weak_raw_ptr(T* p) noexcept : p_(p)
{
if (!p)
return;
p->add_destroy_notify_callback(this, ¬ify_object_invalidated);
}
inline weak_raw_ptr(const weak_raw_ptr& src) noexcept : p_(src.p_)
{
if (p_)
p_->add_destroy_notify_callback(this, ¬ify_object_invalidated);
}
inline weak_raw_ptr& operator=(const weak_raw_ptr& src) noexcept
{
if (p_)
{
p_->remove_destroy_notify_callback(this);
}
p_ = src.p_;
if (p_)
p_->add_destroy_notify_callback(this, ¬ify_object_invalidated);
return *this;
}
// TODO:
weak_raw_ptr(weak_raw_ptr&& src) = delete;
weak_raw_ptr& operator=(weak_raw_ptr&& src) = delete;
inline ~weak_raw_ptr() noexcept
{
if (p_)
{
p_->remove_destroy_notify_callback(this);
}
}
inline explicit operator bool() const noexcept { return p_ != nullptr; }
inline T* operator->() const noexcept { return p_; }
private:
/** Callback that is executed when the objet is destroyed.
* @param data The object notified (@p this).
*/
static void notify_object_invalidated(notifiable* data)
{
auto self = static_cast<weak_raw_ptr*>(data);
if (!self)
return;
self->p_ = nullptr;
}
T* p_;
};
} /* namespace internal */
} /* namespace sigc */
#endif /* SIGC_WEAK_RAW_PTR_HPP */
|
