Developer Documentation

SingletonT.hh
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41
42
43
44
45 //=============================================================================
46 //
47 // Implements a simple singleton template
48 //
49 //=============================================================================
50
51
52 #ifndef __SINGLETON_HH__
53 #define __SINGLETON_HH__
54
55
56 //=== INCLUDES ================================================================
57
58 // OpenMesh
59 #include <OpenMesh/Core/System/config.h>
60
61 // STL
62 #include <stdexcept>
63
64
65 //== NAMESPACES ===============================================================
66
67
68 namespace OpenMesh {
69
70
71 //=== IMPLEMENTATION ==========================================================
72
73
78 template <typename T>
79 class SingletonT
80 {
81 public:
82
89 static T& Instance()
90 {
91 if (!pInstance__)
92 {
93 // check if singleton alive
94 if (destroyed__)
95 {
96 OnDeadReference();
97 }
98 // first time request -> initialize
99 else
100 {
101 Create();
102 }
103 }
104 return *pInstance__;
105 }
106
107
108 private:
109
110 // Disable constructors/assignment to enforce uniqueness
111 SingletonT();
112 SingletonT(const SingletonT&);
113 SingletonT& operator=(const SingletonT&);
114
115 // Create a new singleton and store its pointer
116 static void Create()
117 {
118 static T theInstance;
119 pInstance__ = &theInstance;
120 }
121
122 // Will be called if instance is accessed after its lifetime has expired
123 static void OnDeadReference()
124 {
125 throw std::runtime_error("[Singelton error] - Dead reference detected!\n");
126 }
127
128 virtual ~SingletonT()
129 {
130 pInstance__ = 0;
131 destroyed__ = true;
132 }
133
134 static T* pInstance__;
135 static bool destroyed__;
136 };
137
138
139
140 //=============================================================================
141 } // namespace OpenMesh
142 //=============================================================================
143 #if defined(OM_INCLUDE_TEMPLATES) && !defined(OPENMESH_SINGLETON_C)
144 # define OPENMESH_SINGLETON_TEMPLATES
145 # include "SingletonT_impl.hh"
146 #endif
147 //=============================================================================
148 #endif // __SINGLETON_HH__
149 //=============================================================================
OpenMesh::SingletonT
Definition: SingletonT.hh:79
config.h
OpenMesh::SingletonT::Instance
static T & Instance()
Definition: SingletonT.hh:89
OpenMesh
Definition: MeshItems.hh:59