VTK/Examples/Cxx/Utilities/DetermineVariableType

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This example demonstrates the GetClassName function. This should be available for every VTK class. This is extremely helpful for debugging - you are able to determine the type of a variable that is passed as an abstract type. With this information, the list of functions that can be called on this variable can be determined.

The example illustrates alternative ways to get the "name" of a class. Notice that the GetClassName provides a simple and useful solution.

GetClassName.cxx

#include <vtkSmartPointer.h>
#include <vtkPoints.h>
#include <typeinfo>
 
static const char *unmangleName (const char * name);
 
int main(int, char *[])
{
  vtkSmartPointer<vtkPoints> points = 
    vtkSmartPointer<vtkPoints>::New();
 
  std::cout << "points->GetClassName():             "
            << points->GetClassName() << std::endl;
  std::cout << "Mangled" << std::endl;
  std::cout << "\ttypeid(points).name():              "
            << typeid(points).name() << std::endl;
  std::cout << "\ttypeid(points.GetPointer()).name(): "
            << typeid(points.GetPointer()).name() << std::endl;
  std::cout << "Unmangled" << std::endl;
  std::cout << "\ttypeid(points.GetPointer()).name(): "
            << unmangleName(typeid(points).name()) << std::endl;
  std::cout << "\ttypeid(points.GetPointer()).name(): "
            << unmangleName(typeid(points.GetPointer()).name()) << std::endl;
  return EXIT_SUCCESS;
}
 
// Better name demangling for gcc
#if __GNUC__ > 3 || ( __GNUC__ == 3 && __GNUC_MINOR__ > 0 )
#define GCC_USEDEMANGLE
#endif
 
#ifdef GCC_USEDEMANGLE
#include <cstdlib>
#include <cxxabi.h>
#endif
 
const char *unmangleName (const char * name)
{
#ifdef GCC_USEDEMANGLE
  char const *mangledName = name;
  int         status;
  char *      unmangled = abi::__cxa_demangle(mangledName, 0, 0, &status);
  return unmangled;
#else
  return name;
#endif
}

CMakeLists.txt

cmake_minimum_required(VERSION 2.6)
 
PROJECT(GetClassName)
 
FIND_PACKAGE(VTK REQUIRED)
INCLUDE(${VTK_USE_FILE})
 
ADD_EXECUTABLE(GetClassName GetClassName.cxx)
TARGET_LINK_LIBRARIES(GetClassName vtkHybrid)
Retrieved from "http://www.cmake.org/Wiki/VTK/Examples/Cxx/Utilities/DetermineVariableType"
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