Commit | Line | Data |
---|---|---|
0e23f538 TJ |
1 | /* |
2 | The software in this package is distributed under the GNU General | |
3 | Public License version 2 (with a special exception described below). | |
4 | ||
5 | A copy of GNU General Public License (GPL) is included in this distribution, | |
6 | in the file COPYING.GPL. | |
7 | ||
8 | As a special exception, if other files instantiate templates or use macros | |
9 | or inline functions from this file, or you compile this file and link it | |
10 | with other works to produce a work based on this file, this file | |
11 | does not by itself cause the resulting work to be covered | |
12 | by the GNU General Public License. | |
13 | ||
14 | However the source code for this file must still be made available | |
15 | in accordance with section (3) of the GNU General Public License. | |
16 | ||
17 | This exception does not invalidate any other reasons why a work based | |
18 | on this file might be covered by the GNU General Public License. | |
19 | */ | |
e525f445 RP |
20 | /** @file |
21 | * @brief provides a little base class for classes wich are used in conjunction with shared pointer. | |
22 | * | |
0e23f538 | 23 | * @author Reinhard Pfau |
e525f445 RP |
24 | * |
25 | * @copyright © Copyright 2008 Intra2Net AG | |
e525f445 RP |
26 | * |
27 | */ | |
28 | ||
29 | #ifndef __I2N_POINTER_FUNC_HPP__ | |
30 | #define __I2N_POINTER_FUNC_HPP__ | |
31 | ||
32 | #include <boost/shared_ptr.hpp> | |
33 | #include <boost/enable_shared_from_this.hpp> | |
34 | ||
35 | namespace I2n | |
36 | { | |
37 | ||
38 | ||
39 | /** | |
40 | * @brief base class for classes used as type with shared pointers. | |
41 | * | |
42 | * Must be virtually inherited by (base) classes which are used in | |
43 | * conjunction with shared pointers. | |
44 | * | |
45 | * Allows these classes (and its derived classes) to protect their methods | |
46 | * against preliminary deletion by giving them the possibility to obtain | |
47 | * a shared pointer to themself. | |
48 | */ | |
49 | class SharedBase | |
50 | : public boost::enable_shared_from_this< SharedBase > | |
51 | { | |
52 | public: | |
53 | typedef boost::shared_ptr< SharedBase > BasePtrType; | |
54 | typedef boost::shared_ptr< SharedBase > PtrType; | |
55 | ||
56 | public: | |
57 | SharedBase(); | |
58 | virtual ~SharedBase(); | |
59 | ||
60 | ||
61 | /** | |
62 | * @brief gets a shared pointer to itself if applicable. | |
63 | * @return the shared pointer (to the base class); empty if not applicable. | |
64 | * | |
65 | * The method catches the @a boost::bad_weak_ptr exception and ignores it. | |
66 | * So this method doesn't throw if the instance is not held by a shared pointer. | |
67 | */ | |
68 | BasePtrType get_base_ptr() | |
69 | { | |
70 | BasePtrType result; | |
71 | try { | |
72 | result = shared_from_this(); | |
73 | } | |
74 | catch (boost::bad_weak_ptr) | |
75 | { | |
76 | } | |
77 | return result; | |
78 | } // eo get_base_ptr | |
79 | ||
80 | ||
81 | /** | |
82 | * @brief gets a shared pointer to itself with a specific (derived) type. | |
83 | * @tparam T the desired type for the shared pointer. | |
84 | * @return the shared pointer (to the desired type); empty if not applicable. | |
85 | * | |
86 | * The method catches the @a boost::bad_weak_ptr exception and ignores it. | |
87 | * So this method doesn't throw if the instance is not held by a shared pointer. | |
88 | */ | |
89 | template< class T > | |
90 | boost::shared_ptr< T > get_ptr_as() | |
91 | { | |
92 | boost::shared_ptr< T > result; | |
93 | BasePtrType ptr; | |
94 | try { | |
95 | ptr = shared_from_this(); | |
96 | } | |
97 | catch (boost::bad_weak_ptr) | |
98 | { | |
99 | } | |
100 | if (ptr) | |
101 | { | |
0a4178cf | 102 | result= boost::dynamic_pointer_cast< T >(ptr); |
e525f445 RP |
103 | } |
104 | return result; | |
105 | } // eo get_ptr_as | |
106 | ||
107 | ||
108 | }; // eo SharedBase | |
109 | ||
110 | typedef SharedBase::PtrType SharedBasePtr; | |
111 | ||
112 | } // eo namespace I2n | |
113 | ||
114 | #endif |