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 » castScreenshots 
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(dpdp->derivedOnly();
  else
    cout << "Cast from Base to Derived failed.\n";
   
  bp = &d_ob;
  dp = dynamic_cast<Derived *> (bp);
  if(dpdp->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.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.
www.java2java.com | Contact Us
Copyright 2009 - 12 Demo Source and Support. All rights reserved.
All other trademarks are property of their respective owners.