call the print_house_details function using the ptr_to_house variable

To call the `print_house_details()` function using the `ptr_to_house` variable, you first need to create an instance of the `house` class and assign its address to `ptr_to_house`. Here's an example:

#include <iostream>
#include "house.h"

int main() {
    // Create a new house object
    house my_house("123 Main St", 3, 1998);

    // Create a pointer to the house object
    house* ptr_to_house = &my_house;

    // Call the print_house_details function using the pointer
    ptr_to_house->print_house_details();

    return 0;
}

In this example, we create a `house` object called `my_house` with the location "123 Main St", 3 rooms, and built in 1998. We then create a pointer `ptr_to_house` and assign it the address of `my_house`. Finally, we call the `print_house_details()` function using the pointer and the arrow operator `->`. This will output:

Location: 123 Main St
Number of rooms: 3
Year built: 1998