bad_cast class
Remonter à typeinfo.h - Index
Header File
typeinfo.h
Description
When dynamic_cast fails to make a cast to reference, the expression can throw bad_cast. Note that when dynamic_cast fails to make a cast to pointer type, the result is the null pointer.
Example
#include <iostream>
#include <typeinfo.h>
using std::cout;
class __rtti Alpha {
virtual void func() {}; // This makes Alpha a polymorphic class type.
};
class B : public Alpha {};
int main(void)
{
B Binst; // Instantiate class B
B *Bptr; // Declare a B-type pointer
Bptr = &Binst; // Initialize the pointer
// THESE TESTS ARE DONE AT RUN TIME
// Ask "WHAT IS THE TYPE FOR *Bptr?"
if (typeid( *Bptr ) == typeid( B ) )
cout << "Name is " << typeid( *Bptr).name();
if (typeid( *Bptr ) != typeid( Alpha ) )
cout << "\nPointer is not an Alpha-type.";
return 0;
}
Sortie du programme
Name is B
Pointer is not an Alpha-type.