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
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
|
/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2006 Robert Osfield
*
* This library is open source and may be redistributed and/or modified under
* the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or
* (at your option) any later version. The full license is in LICENSE file
* included with this distribution, and on the openscenegraph.org website.
*
* 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
* OpenSceneGraph Public License for more details.
*/
#ifndef OSG_REF_PTR
#define OSG_REF_PTR 1
#include <osg/Config>
#ifdef OSG_USE_REF_PTR_SAFE_DEREFERENCE
#include <typeinfo>
#include <stdexcept>
#include <string>
#endif
namespace osg {
template<typename T> class observer_ptr;
/** Smart pointer for handling referenced counted objects.*/
template<class T>
class ref_ptr
{
public:
typedef T element_type;
ref_ptr() : _ptr(0) {}
ref_ptr(T* ptr) : _ptr(ptr) { if (_ptr) _ptr->ref(); }
ref_ptr(const ref_ptr& rp) : _ptr(rp._ptr) { if (_ptr) _ptr->ref(); }
template<class Other> ref_ptr(const ref_ptr<Other>& rp) : _ptr(rp._ptr) { if (_ptr) _ptr->ref(); }
ref_ptr(observer_ptr<T>& optr) : _ptr(0) { optr.lock(*this); }
~ref_ptr() { if (_ptr) _ptr->unref(); _ptr = 0; }
ref_ptr& operator = (const ref_ptr& rp)
{
assign(rp);
return *this;
}
template<class Other> ref_ptr& operator = (const ref_ptr<Other>& rp)
{
assign(rp);
return *this;
}
inline ref_ptr& operator = (T* ptr)
{
if (_ptr==ptr) return *this;
T* tmp_ptr = _ptr;
_ptr = ptr;
if (_ptr) _ptr->ref();
// unref second to prevent any deletion of any object which might
// be referenced by the other object. i.e rp is child of the
// original _ptr.
if (tmp_ptr) tmp_ptr->unref();
return *this;
}
#ifdef OSG_USE_REF_PTR_IMPLICIT_OUTPUT_CONVERSION
// implicit output conversion
operator T*() const { return _ptr; }
#else
// comparison operators for ref_ptr.
bool operator == (const ref_ptr& rp) const { return (_ptr==rp._ptr); }
bool operator == (const T* ptr) const { return (_ptr==ptr); }
friend bool operator == (const T* ptr, const ref_ptr& rp) { return (ptr==rp._ptr); }
bool operator != (const ref_ptr& rp) const { return (_ptr!=rp._ptr); }
bool operator != (const T* ptr) const { return (_ptr!=ptr); }
friend bool operator != (const T* ptr, const ref_ptr& rp) { return (ptr!=rp._ptr); }
bool operator < (const ref_ptr& rp) const { return (_ptr<rp._ptr); }
// follows is an implementation of the "safe bool idiom", details can be found at:
// http://en.wikibooks.org/wiki/More_C%2B%2B_Idioms/Safe_bool
// http://lists.boost.org/Archives/boost/2003/09/52856.php
private:
typedef T* ref_ptr::*unspecified_bool_type;
public:
// safe bool conversion
operator unspecified_bool_type() const { return valid()? &ref_ptr::_ptr : 0; }
#endif
T& operator*() const
{
#ifdef OSG_USE_REF_PTR_SAFE_DEREFERENCE
if( !_ptr ) {
// pointer is invalid, so throw an exception
throw std::runtime_error(std::string("could not dereference invalid osg pointer ") + std::string(typeid(T).name()));
}
#endif
return *_ptr;
}
T* operator->() const
{
#ifdef OSG_USE_REF_PTR_SAFE_DEREFERENCE
if( !_ptr ) {
// pointer is invalid, so throw an exception.
throw std::runtime_error(std::string("could not call invalid osg pointer ") + std::string(typeid(T).name()));
}
#endif
return _ptr;
}
T* get() const { return _ptr; }
bool operator!() const { return _ptr==0; } // not required
bool valid() const { return _ptr!=0; }
/** release the pointer from ownership by this ref_ptr<>, decrementing the objects refencedCount() via unref_nodelete() to prevent the Object
* object from being deleted even if the reference count goes to zero. Use when using a local ref_ptr<> to an Object that you want to return
* from a function/method via a C pointer, whilst preventing the normal ref_ptr<> destructor from cleaning up the object. When using release()
* you are implicitly expecting other code to take over management of the object, otherwise a memory leak will result. */
T* release() { T* tmp=_ptr; if (_ptr) _ptr->unref_nodelete(); _ptr=0; return tmp; }
void swap(ref_ptr& rp) { T* tmp=_ptr; _ptr=rp._ptr; rp._ptr=tmp; }
private:
template<class Other> void assign(const ref_ptr<Other>& rp)
{
if (_ptr==rp._ptr) return;
T* tmp_ptr = _ptr;
_ptr = rp._ptr;
if (_ptr) _ptr->ref();
// unref second to prevent any deletion of any object which might
// be referenced by the other object. i.e rp is child of the
// original _ptr.
if (tmp_ptr) tmp_ptr->unref();
}
template<class Other> friend class ref_ptr;
T* _ptr;
};
template<class T> inline
void swap(ref_ptr<T>& rp1, ref_ptr<T>& rp2) { rp1.swap(rp2); }
template<class T> inline
T* get_pointer(const ref_ptr<T>& rp) { return rp.get(); }
template<class T, class Y> inline
ref_ptr<T> static_pointer_cast(const ref_ptr<Y>& rp) { return static_cast<T*>(rp.get()); }
template<class T, class Y> inline
ref_ptr<T> dynamic_pointer_cast(const ref_ptr<Y>& rp) { return dynamic_cast<T*>(rp.get()); }
template<class T, class Y> inline
ref_ptr<T> const_pointer_cast(const ref_ptr<Y>& rp) { return const_cast<T*>(rp.get()); }
}
#endif
|
