Using Const Cast

The following is an example to use the const_cast in C++.

//Program tested on Microsoft Visual Studio 2008 - Zahid Ghadialy
//Example shows how to use const_cast
#include<iostream>

using namespace std;

void func1(int *x)
{
  cout<<"\n2. xyz = "<<*x<<endl;

  //Possible but its like cheating
  (*x)++;
}


void func2(const int *x)
{
  cout<<"\n4. xyz = "<<*x<<endl;
  //(*x)++; //Not possible to do this, compile time error
}

int main()
{
  int xyz = 22;
  const int *abc = &xyz;
  cout<<"\n1. xyz = "<<xyz<<endl;
  //func1(abc); //Not possible to call, need a cast, compile time error
  //Use const_cast only when you trust a function to not change the value
  func1(const_cast<int *>(abc)); //Cast the constness of abc away
  cout<<"\n3. xyz = "<<xyz<<endl;
  func2(abc);
  cout<<"\n5. xyz = "<<xyz<<endl;
}

The output of the program is as follows: