File: sample.rs
   1   struct Rectangle {
   2       width: u32,
   3       height: u32,
   4   }
   5   
   6 _ fn main() {
   7       let rect1 = Rectangle { width: 30, height: 50 };
   8   
   9       println!(
  10 ~         "The perimeter of the rectangle is {} pixels.",
  11 ~         perimeter(&rect1)
  12       );
  13   }
  14   
  15   fn area(rectangle: &Rectangle) -> u32 {
  16       rectangle.width * rectangle.height
  17   }
  18 + 
  19 + fn perimeter(rectangle: &Rectangle) -> u32 {
  20 +     (rectangle.width + rectangle.height) * 2
  21 + }