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comparison engine/core/util/base/singleton.h @ 0:4a0efb7baf70

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* Datasets becomes the new trunk and retires after that :-)
author mvbarracuda@33b003aa-7bff-0310-803a-e67f0ece8222
date Sun, 29 Jun 2008 18:44:17 +0000
parents
children 90005975cdbb
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-1:000000000000 0:4a0efb7baf70
1 /***************************************************************************
2 * Copyright (C) 2005-2008 by the FIFE team *
3 * http://www.fifengine.de *
4 * This file is part of FIFE. *
5 * *
6 * FIFE is free software; you can redistribute it and/or modify *
7 * it under the terms of the GNU General Public License as published by *
8 * the Free Software Foundation; either version 2 of the License, or *
9 * (at your option) any later version. *
10 * *
11 * This program is distributed in the hope that it will be useful, *
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of *
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
14 * GNU General Public License for more details. *
15 * *
16 * You should have received a copy of the GNU General Public License *
17 * along with this program; if not, write to the *
18 * Free Software Foundation, Inc., *
19 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA *
20 ***************************************************************************/
21
22 #ifndef FIFE_SINGLETON_H
23 #define FIFE_SINGLETON_H
24
25 #define SINGLEFRIEND(classname) friend class FIFE::StaticSingleton<classname>; classname(); virtual ~classname();
26
27 // Standard C++ library includes
28 #include <cassert>
29
30 // 3rd party library includes
31
32 // FIFE includes
33 // These includes are split up in two parts, separated by one empty line
34 // First block: files included from the FIFE root src directory
35 // Second block: files included from the same folder
36 #include "fifeclass.h"
37
38 namespace FIFE {
39
40 /** The "classic" Singleton.
41 *
42 * @see DynamicSingleton
43 */
44 template <typename T> class StaticSingleton: public FifeClass {
45 public:
46
47 static T* instance() {
48 static T inst;
49 return &inst;
50 }
51
52 protected:
53
54 StaticSingleton(): FifeClass() {
55 }
56
57 virtual ~StaticSingleton() {
58 }
59
60 private:
61 StaticSingleton(const StaticSingleton<T>&): FifeClass() {}
62 StaticSingleton<T>& operator=(const StaticSingleton<T>&) {
63 return this;
64 }
65
66 };
67
68 /** Another Singleton.
69 *
70 * This implementations needs to be created and destroyed explicitly.
71 * That way the order of construction and destruction is well defined, so we don't
72 * get those nasty static initialization/destruction order problems.
73 *
74 * Engine will create all standard FIFE Singletons when created (just call Engine::instance())
75 * and destroy them on exit.
76 *
77 * Maybe we'll change this one day to use one of those funny NiftyCounter implementations.
78 *
79 * @see StaticSingleton
80 * @see Engine
81 */
82 template <typename T> class DynamicSingleton: public FifeClass {
83 public:
84 static T* instance() {
85 assert(m_instance);
86 return m_instance;
87 }
88
89 DynamicSingleton(): FifeClass() {
90 assert(!m_instance);
91 m_instance = static_cast<T*>(this);
92 }
93
94 virtual ~DynamicSingleton() {
95 m_instance = 0;
96 }
97
98 private:
99 static T* m_instance;
100
101 DynamicSingleton(const DynamicSingleton<T>&): FifeClass() {};
102 DynamicSingleton<T&> operator=(const DynamicSingleton<T>&) {};
103
104 };
105
106 template <typename T> T* DynamicSingleton<T>::m_instance = 0;
107
108 }//FIFE
109
110 #endif