Example of C++ Templates

Program to show how templates work in a very simple way:

//Program tested on Microsoft Visual Studio 2008 - Zahid Ghadialy
//Note this program shows Template example

#include<iostream>

using namespace std;

template <class T> class Arith
{
public:
  T Add(T a, T b)
  {
    return a + b;
  }
};

template <class T, class U> class ArithNew
{
public:
  T Add(T a, U b)
  {
    return (T)(a + b); //the return type is casted otherwise a warning will be generated
  }
};

int main(void)
{
  Arith<int> ar1;
  int x = ar1.Add(3, 5);
  cout<<"x = "<<x<<endl;

  Arith<double> ar2;
  double y = ar2.Add(3.3, 1.2);
  cout<<"y = "<<y<<endl;

  //Arith<int> ar3;
  //double z = ar3.Add(3, 1.2);
  //cout<<"z = "<<z<<endl;
  //The above is possible but loss of data and no flexibility. Cant mix two types

  ArithNew<double, int> ar4;
  double xx = ar4.Add(5.5, 2);
  cout<<"xx = "<<xx<<endl;

  //reversing the same as above
  ArithNew<int, double> ar5;
  int yy = ar5.Add(2, 5.5); //works without warning because of return type being casted otherwise warning
  cout<<"yy = "<<yy<<endl;

  return 0;
}