Casting numbers

This is an interesting concept.
Trying to use different variable types together presents interesting dilemmas.
Watch the video below and you will understand what I mean  
​

Scenario

​Comparing floating-point numbers in C++ may lead to unexpected results.
​
​Run the following program and modify the is_close function to get the desired results.

Sample Code

#include <iostream>
#include <math.h>

using namespace std;


bool is_close(double a, double b, double tolerance){
     // Your code goes here
     return false;
}


int main(void) {

if (0.3 == 3 * 0.1) {
     cout << "The numbers are equal";
     }
​else {
     cout << "The numbers are not equal";
     }
     cout << endl;

if (is_close(0.3, 3 * 0.1, 0.00000001)) {
     cout << "The numbers are close enough";
     }
else {
     cout << "The numbers are not close enough";
     }
    cout << endl;

// this should work regardless of the argument order
if (is_close(3 * 0.1, 0.3, 0.00000001)) {
     cout << "The numbers are still close enough";
     }
else {
     cout << "The numbers are not close enough";
     }
     cout << endl;

if (is_close(3 * 0.1, 0.31, 0.00000001)) {
     cout << "The numbers are still close enough";
     }
else {
     cout << "The numbers are not close enough";
     }
     cout <<endl
​
return 0;
}

Sample Output

The numbers are not equal
The numbers are close enough
The numbers are still close enough
​The numbers are not close enough