Visual Servoing Platform  version 3.6.1 under development (2024-05-08)
vpNullptrEmulated.h
1 /*
2  * ViSP, open source Visual Servoing Platform software.
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10  * distribution for additional information about the GNU GPL.
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12  * For using ViSP with software that can not be combined with the GNU
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30 
31 #ifndef _vpNullptrEmulated_h_
32 #define _vpNullptrEmulated_h_
33 
34 #include <visp3/core/vpConfig.h>
35 
36 // Note that on ubuntu 12.04 __cplusplus is equal to 1 that's why in the next line we consider __cplusplus <= 199711L
37 // and not __cplusplus == 199711L
38 #if (!defined(VISP_HAVE_NULLPTR)) && (__cplusplus <= 199711L)
39 
40 // Inspired from this thread https://stackoverflow.com/questions/24433436/compile-error-nullptr-undeclared-identifier
41 // Does the emulation of nullptr when not available with cxx98
42 const
43 class nullptr_t
44 {
45 public:
46  template<class T>
47  inline operator T *() const // convertible to any type of null non-member pointer...
48  {
49  return 0;
50  }
51 
52  template<class C, class T>
53  inline operator T C:: *() const // or any type of null member pointer...
54  {
55  return 0;
56  }
57 
58 private:
59  void operator&() const; // Can't take address of nullptr
60 
61 } nullptr = {};
62 
63 #endif
64 #endif