tuple::new can take any type of number

features/src/structs.rs

@@ -10,12 +10,12 @@ pub struct Tuple {
 }
 
 impl Tuple {
-    pub fn new(x: f32, y: f32, z: f32, w: f32) -> Tuple {
+    pub fn new<T: num_traits::NumCast>(x: T, y: T, z: T, w: T) -> Tuple {
         Tuple {
-            x,
-            y,
-            z,
-            w,
+            x: num_traits::cast(x).unwrap(),
+            y: num_traits::cast(y).unwrap(),
+            z: num_traits::cast(z).unwrap(),
+            w: num_traits::cast(w).unwrap(),
         }
     }
 
@@ -424,4 +424,12 @@ mod tests {
          let b_cross_a = Tuple::vector(1.0, -2.0, 1.0);
          assert_eq!(b_cross_a, b.cross(&a));
      }
+
+     #[test]
+     fn works_with_i32() {
+         let a = Tuple::new(1, 2, 3);
+         assert_eq!(1.0, a.x());
+         assert_eq!(2.0, a.y());
+         assert_eq!(3.0, a.z());
+     }
 }