OpenMesh: OpenMesh/Core/Utils/SingletonT.hh Source File

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SingletonT.hh
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42 /*===========================================================================*\
43 * *
44 * $Revision$ *
45 * $Date$ *
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47 \*===========================================================================*/
48
49
50 //=============================================================================
51 //
52 // Implements a simple singleton template
53 //
54 //=============================================================================
55
56
57 #ifndef __SINGLETON_HH__
58 #define __SINGLETON_HH__
59
60
61 //=== INCLUDES ================================================================
62
63 // OpenMesh
64 #include <OpenMesh/Core/System/config.h>
65
66 // STL
67 #include <stdexcept>
68
69
70 //== NAMESPACES ===============================================================
71
72
73 namespace OpenMesh {
74
75
76 //=== IMPLEMENTATION ==========================================================
77
78
83 template <typename T>
84 class SingletonT
85 {
86 public:
87
94 static T& Instance()
95 {
96 if (!pInstance__)
97 {
98 // check if singleton alive
99 if (destroyed__)
100 {
101 OnDeadReference();
102 }
103 // first time request -> initialize
104 else
105 {
106 Create();
107 }
108 }
109 return *pInstance__;
110 }
111
112
113 private:
114
115 // Disable constructors/assignment to enforce uniqueness
116 SingletonT();
117 SingletonT(const SingletonT&);
118 SingletonT& operator=(const SingletonT&);
119
120 // Create a new singleton and store its pointer
121 static void Create()
122 {
123 static T theInstance;
124 pInstance__ = &theInstance;
125 }
126
127 // Will be called if instance is accessed after its lifetime has expired
128 static void OnDeadReference()
129 {
130 throw std::runtime_error("[Singelton error] - Dead reference detected!\n");
131 }
132
133 virtual ~SingletonT()
134 {
135 pInstance__ = 0;
136 destroyed__ = true;
137 }
138
139 static T* pInstance__;
140 static bool destroyed__;
141 };
142
143
144
145 //=============================================================================
146 } // namespace OpenMesh
147 //=============================================================================
148 #if defined(OM_INCLUDE_TEMPLATES) && !defined(OPENMESH_SINGLETON_C)
149 # define OPENMESH_SINGLETON_TEMPLATES
150 # include "SingletonT.cc"
151 #endif
152 //=============================================================================
153 #endif // __SINGLETON_HH__
154 //=============================================================================
OpenMesh::SingletonT::Instance
static T & Instance()
Singleton access function.
Definition: SingletonT.hh:94
OpenMesh
Contains all the mesh ingredients like the polygonal mesh, the triangle mesh, different mesh kernels ...
Definition: MeshItems.hh:64
OpenMesh::SingletonT
A simple singleton template.
Definition: SingletonT.hh:84