Mention importance of template. write a program to swap contents of two variables of type int, float and double using function template

 Templates in C++ are an important features that allow us to write generic code that can work with different data types. With templates, we can write code once and use it for any data type, without having to write separate code for each data type. This makes our code more flexible and reusable, and reduces code duplication.

Here is a program to swap contents of two variables of type int, float, and double using function templates:

#include <iostream>

using namespace std;

// Function template to swap two variables of any type

template <typename T>

void swap(T& a, T& b)

{

    T temp = a;

    a = b;

    b = temp;

}

int main()

{

    int x = 6, y = 9;

    float p = 6.9, q = 3.6;

    double m = 3.14145, n = 4.72983;

    // Swap two integers

    swap(x, y);

    cout << "After swapping: x = " << x << ", y = " << y << endl;

    // Swap two floats

    swap(p, q);

    cout << "After swapping: p = " << p << ", q = " << q << endl;

    // Swap two doubles

    swap(m, n);

    cout << "After swapping: m = " << m << ", n = " << n << endl;

    return 0;

}

In this program, we define a function template "swap" that takes two parameters of type "T", which can be any data type. Inside the function, we swap the values of the two parameters using a temporary variable "temp".

In the "main" function, we call the "swap" function with integers, floats and doubles, and then print the values of the variables to verify that they have been swapped correctly. The function template "swap" is automatically instantiated by the compiler for each data type used in the program.