Commit | Line | Data |
---|---|---|
6edafdc0 | 1 | use std::ops::{Add, AddAssign, Mul}; |
296187ca | 2 | |
787dbfb4 | 3 | #[macro_export] |
296187ca TW |
4 | macro_rules! point { |
5 | ( $x:expr, $y:expr ) => { Point2D { x:$x, y:$y } }; | |
6 | } | |
7 | ||
8 | #[derive(Debug, Copy, Clone, PartialEq)] | |
9 | pub struct Point2D<T> { | |
10 | pub x: T, | |
11 | pub y: T, | |
12 | } | |
13 | ||
14 | impl Point2D<f64> { | |
15 | pub fn length(self) -> f64 { | |
16 | ((self.x * self.x) + (self.y * self.y)).sqrt() | |
17 | } | |
18 | } | |
19 | ||
20 | impl<T: Add<Output=T>> Add for Point2D<T> { | |
21 | type Output = Point2D<T>; | |
22 | ||
23 | fn add(self, rhs: Point2D<T>) -> Self::Output { | |
24 | Point2D { x: self.x + rhs.x, y: self.y + rhs.y } | |
25 | } | |
26 | } | |
27 | ||
28 | impl<T: AddAssign> AddAssign for Point2D<T> { | |
29 | fn add_assign(&mut self, rhs: Point2D<T>) { | |
30 | self.x += rhs.x; | |
31 | self.y += rhs.y; | |
32 | } | |
33 | } | |
34 | ||
6edafdc0 TW |
35 | #[derive(Default)] |
36 | pub struct Rect<T> { | |
37 | pub width: T, | |
38 | pub height: T, | |
39 | } | |
40 | ||
41 | impl<T: Mul<Output=T> + Copy> Rect<T> { | |
42 | #[allow(dead_code)] | |
43 | pub fn area(&self) -> T { | |
44 | self.width * self.height | |
45 | } | |
46 | } | |
47 | ||
48 | impl<T> From<(T, T)> for Rect<T> { | |
49 | fn from(item: (T, T)) -> Self { | |
50 | Rect { width: item.0, height: item.1 } | |
51 | } | |
52 | } | |
53 | ||
296187ca TW |
54 | #[cfg(test)] |
55 | mod tests { | |
56 | use super::*; | |
57 | ||
58 | #[test] | |
59 | fn immutable_copy_of_point() { | |
60 | let a = point!(0, 0); | |
61 | let mut b = a; // Copy | |
62 | assert_eq!(a, b); // PartialEq | |
63 | b.x = 1; | |
64 | assert_ne!(a, b); // PartialEq | |
65 | } | |
66 | ||
67 | #[test] | |
68 | fn add_points() { | |
69 | let mut a = point!(1, 0); | |
70 | assert_eq!(a + point!(2, 2), point!(3, 2)); // Add | |
71 | a += point!(2, 2); // AddAssign | |
72 | assert_eq!(a, point!(3, 2)); | |
73 | } | |
6edafdc0 TW |
74 | |
75 | #[test] | |
76 | fn area_for_rect_of_multipliable_type() { | |
77 | let r: Rect<_> = (30, 20).into(); // the Into trait uses the From trait | |
78 | assert_eq!(r.area(), 30 * 20); | |
79 | // let a = Rect::from(("a".to_string(), "b".to_string())).area(); // this doesn't work, because area() is not implemented for String | |
80 | } | |
296187ca | 81 | } |