add sub

ops-test/src/main.rs

@@ -15,11 +15,24 @@ impl std::ops::Add<Point> for Point {
     }
 }
 
+impl std::ops::Sub<Point> for Point {
+    type Output = Self;
+
+    fn sub(self, rhs: Self) -> Self {
+        Point {
+            x: self.x - rhs.x,
+            y: self.y - rhs.y,
+        }
+    }
+}
+
 fn main() {
     let a = Point { x: 1, y: 2, };
     let b = Point { x: 2, y: 4, };
-    let c = a.clone() + b;
+    let c = a.clone() + b.clone();
+    let d = a.clone() - b.clone();
     println!("{:?}", a);
-    // println!("{:?}", b);
+    println!("{:?}", b);
     println!("{:?}", c);
+    println!("{:?}", d);
 }