Debug trait fun

rustbook/rectangles/src/main.rs

@@ -1,3 +1,4 @@
+#[derive(Debug)]
 struct Rectangle {
     width: u32,
     height: u32,
@@ -6,6 +7,8 @@ struct Rectangle {
 fn main() {
     let rect1 = Rectangle { width: 30, height: 50 };
 
+    println!("rect1 is {:?}", rect1);
+
     println!(
         "The area of the rectangle is {} square pixels.",
         area(&rect1)