CXXR (C++ R)
SEXP_downcast.hpp
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1 /*CXXR $Id: SEXP_downcast.hpp 1397 2013-08-16 18:25:59Z arr $
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34 
38 #ifndef SEXP_DOWNCAST_HPP
39 #define SEXP_DOWNCAST_HPP 1
40 
41 #include "CXXR/RObject.h"
42 
43 namespace CXXR {
44 #ifdef __GNUC__
45  __attribute__((noreturn))
46 #endif
47 
51  void SEXP_downcast_error(const char* given, const char* wanted);
52 
70 #ifdef UNCHECKED_SEXP_DOWNCAST
71  template <typename PtrOut, typename PtrIn>
72  inline PtrOut SEXP_downcast(PtrIn s, bool allow_null = true)
73  {
74  if (!s && !allow_null) {
75  PtrOut exemplar = 0;
76  SEXP_downcast_error("NULL", exemplar->staticTypeName());
77  }
78  return static_cast<PtrOut>(s);
79  }
80 #else
81  template <typename PtrOut, typename PtrIn>
82  PtrOut SEXP_downcast(PtrIn s, bool allow_null = true)
83  {
84  PtrOut ans = 0;
85  if (!s) {
86  if (allow_null)
87  return 0;
88  else SEXP_downcast_error("NULL", ans->staticTypeName());
89  }
90  ans = dynamic_cast<PtrOut>(s);
91  if (!ans)
92  SEXP_downcast_error(s->typeName(), ans->staticTypeName());
93  return ans;
94  }
95 #endif
96 } // namespace CXXR
97 
98 #endif // SEXP_DOWNCAST_HPP