color can use any number type

features/src/color.rs

@@ -1,4 +1,6 @@
+use crate::num_traits_cast;
 use std::ops;
+use num_traits::NumCast;
 
 #[derive(Debug, Copy, Clone)]
 pub struct Color {
@@ -8,11 +10,15 @@ pub struct Color {
 }
 
 impl Color {
-    pub fn new(red: f32, green: f32, blue: f32) -> Color {
+    pub fn new<R, G, B>(red: R, green: G, blue: B) -> Color
+    where R: NumCast,
+    G: NumCast,
+    B: NumCast,
+     {
         Color {
-            red,
+            red: num_traits_cast!(red),
-            green,
+            green: num_traits_cast!(green),
-            blue,
+            blue: num_traits_cast!(blue),
         }
     }
 
@@ -112,7 +118,7 @@ mod tests {
     fn add() {
         let c1 = Color::new(0.9, 0.6, 0.75);
         let c2 = Color::new(0.7, 0.1, 0.25);
-        let res = Color::new(1.6, 0.7, 1.0);
+        let res = Color::new(1.6, 0.7, 1);
 
         assert_eq!(res, c1 + c2);
     }
@@ -136,8 +142,8 @@ mod tests {
 
     #[test]
     fn mul() {
-        let c1 = Color::new(1.0, 0.2, 0.4);
+        let c1 = Color::new(1, 0.2, 0.4);
-        let c2 = Color::new(0.9, 1.0, 0.1);
+        let c2 = Color::new(0.9, 1, 0.1);
         let res = Color::new(0.9, 0.2, 0.04);
 
         assert_eq!(res, c1 * c2);