Replacing typeid with dynamic_cast : cast « Class « C++

Home C++ 1. Bitset 2. Class 3. Console 4. Data Structure 5. Data Type 6. Deque 7. Development 8. File 9. Function 10. Generic 11. Language 12. List 13. Map Multimap 14. Overload 15. Pointer 16. Qt 17. Queue Stack 18. Set Multiset 19. STL Algorithms Binary search 20. STL Algorithms Heap 21. STL Algorithms Helper 22. STL Algorithms Iterator 23. STL Algorithms Merge 24. STL Algorithms Min Max 25. STL Algorithms Modifying sequence operations 26. STL Algorithms Non modifying sequence operations 27. STL Algorithms Sorting 28. STL Basics 29. String 30. Valarray 31. Vector C / ANSI-C C Tutorial C++ Tutorial Visual C++ .NET

C++ » Class » cast Screenshots  Replacing typeid with dynamic_cast     #include <iostream> #include <typeinfo> using namespace std;     class Base { public:   virtual void f() {} };     class Derived : public Base { public:   void derivedOnly() {     cout << "Is a Derived Object.\n";   } };     int main() {   Base *bp, b_ob;   Derived *dp, d_ob;       bp = &b_ob;   if(typeid(*bp) == typeid(Derived)) {     dp = (Derived *) bp;     dp->derivedOnly();   }   else     cout << "Cast from Base to Derived failed.\n";       bp = &d_ob;   if(typeid(*bp) == typeid(Derived)) {     dp = (Derived *) bp;     dp->derivedOnly();   }   else     cout << "Error, cast should work!\n";       // use dynamic_cast   bp = &b_ob;   dp = dynamic_cast<Derived *> (bp);   if(dp) dp->derivedOnly();   else     cout << "Cast from Base to Derived failed.\n";       bp = &d_ob;   dp = dynamic_cast<Derived *> (bp);   if(dp) dp->derivedOnly();   else     cout << "Error, cast should work!\n";       return 0; }                 Related examples in the same category 1. Don't need a cast to go up the inheritance hierarchy 2. class type-casting 3. The const_cast operator is used to explicitly override const and/or volatile in a cast. 4. Use const_cast on a const reference. 5. The static_cast operator performs a nonpolymorphic cast. 6. The reinterpret_cast operator converts one type into a fundamentally different type. 7. The dynamic_cast performs a run-time cast that verifies the validity of a cast.