OpenMesh
SingletonT.hh
1/* ========================================================================= *
2 * *
3 * OpenMesh *
4 * Copyright (c) 2001-2025, RWTH-Aachen University *
5 * Department of Computer Graphics and Multimedia *
6 * All rights reserved. *
7 * www.openmesh.org *
8 * *
9 *---------------------------------------------------------------------------*
10 * This file is part of OpenMesh. *
11 *---------------------------------------------------------------------------*
12 * *
13 * Redistribution and use in source and binary forms, with or without *
14 * modification, are permitted provided that the following conditions *
15 * are met: *
16 * *
17 * 1. Redistributions of source code must retain the above copyright notice, *
18 * this list of conditions and the following disclaimer. *
19 * *
20 * 2. Redistributions in binary form must reproduce the above copyright *
21 * notice, this list of conditions and the following disclaimer in the *
22 * documentation and/or other materials provided with the distribution. *
23 * *
24 * 3. Neither the name of the copyright holder nor the names of its *
25 * contributors may be used to endorse or promote products derived from *
26 * this software without specific prior written permission. *
27 * *
28 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS *
29 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED *
30 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A *
31 * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER *
32 * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, *
33 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, *
34 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR *
35 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF *
36 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING *
37 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS *
38 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. *
39 * *
40 * ========================================================================= */
41
42
43
44
45//=============================================================================
46//
47// Implements a simple singleton template
48//
49//=============================================================================
50
51#pragma once
52
53//=== INCLUDES ================================================================
54
55// OpenMesh
56#include <OpenMesh/Core/System/config.h>
57
58// STL
59#include <stdexcept>
60
61
62//== NAMESPACES ===============================================================
63
64
65namespace OpenMesh {
66
67
68//=== IMPLEMENTATION ==========================================================
69
70
75template <typename T>
77{
78public:
79
86 static T& Instance()
87 {
88 if (!pInstance__)
89 {
90 // check if singleton alive
91 if (destroyed__)
92 {
93 OnDeadReference();
94 }
95 // first time request -> initialize
96 else
97 {
98 Create();
99 }
100 }
101 return *pInstance__;
102 }
103
104
105private:
106
107 // Disable constructors/assignment to enforce uniqueness
108 SingletonT();
109 SingletonT(const SingletonT&);
110 SingletonT& operator=(const SingletonT&);
111
112 // Create a new singleton and store its pointer
113 static void Create()
114 {
115 static T theInstance;
116 pInstance__ = &theInstance;
117 }
118
119 // Will be called if instance is accessed after its lifetime has expired
120 static void OnDeadReference()
121 {
122 throw std::runtime_error("[Singelton error] - Dead reference detected!\n");
123 }
124
125 virtual ~SingletonT()
126 {
127 pInstance__ = 0;
128 destroyed__ = true;
129 }
130
131 static T* pInstance__;
132 static bool destroyed__;
133};
134
135
136
137//=============================================================================
138} // namespace OpenMesh
139//=============================================================================
140#if defined(OM_INCLUDE_TEMPLATES) && !defined(OPENMESH_SINGLETON_C)
141# define OPENMESH_SINGLETON_TEMPLATES
142# include "SingletonT_impl.hh"
143#endif
144//=============================================================================
Contains all the mesh ingredients like the polygonal mesh, the triangle mesh, different mesh kernels ...
Definition: MeshItems.hh:59
A simple singleton template.
Definition: SingletonT.hh:77
static T & Instance()
Singleton access function.
Definition: SingletonT.hh:86

Project OpenMesh, ©  Visual Computing Institute, RWTH Aachen. Documentation generated using doxygen .