-use std::ops::{Add, AddAssign};
+use std::ops::{Add, AddAssign, Mul};
+
+pub type Nanoseconds = u64;
#[macro_export]
macro_rules! point {
- ( $x:expr, $y:expr ) => { Point2D { x:$x, y:$y } };
+ ( $x:expr, $y:expr ) => {
+ Point2D { x: $x, y: $y }
+ };
}
-#[derive(Debug, Copy, Clone, PartialEq)]
+#[derive(Debug, Default, Copy, Clone, PartialEq)]
pub struct Point2D<T> {
pub x: T,
pub y: T,
}
}
-impl<T: Add<Output=T>> Add for Point2D<T> {
+impl<T: Add<Output = T>> Add for Point2D<T> {
type Output = Point2D<T>;
fn add(self, rhs: Point2D<T>) -> Self::Output {
- Point2D { x: self.x + rhs.x, y: self.y + rhs.y }
+ Point2D {
+ x: self.x + rhs.x,
+ y: self.y + rhs.y,
+ }
}
}
}
}
+impl<T> From<(T, T)> for Point2D<T> {
+ fn from(item: (T, T)) -> Self {
+ Point2D {
+ x: item.0,
+ y: item.1,
+ }
+ }
+}
+
+#[macro_export]
+macro_rules! rect {
+ ( $x:expr, $y:expr ) => {
+ Rect { x: $x, y: $y }
+ };
+}
+
+#[derive(Default)]
+pub struct Rect<T> {
+ pub width: T,
+ pub height: T,
+}
+
+impl<T: Mul<Output = T> + Copy> Rect<T> {
+ #[allow(dead_code)]
+ pub fn area(&self) -> T {
+ self.width * self.height
+ }
+}
+
+impl<T> From<(T, T)> for Rect<T> {
+ fn from(item: (T, T)) -> Self {
+ Rect {
+ width: item.0,
+ height: item.1,
+ }
+ }
+}
+
#[cfg(test)]
mod tests {
use super::*;
a += point!(2, 2); // AddAssign
assert_eq!(a, point!(3, 2));
}
+
+ #[test]
+ fn area_for_rect_of_multipliable_type() {
+ let r: Rect<_> = (30, 20).into(); // the Into trait uses the From trait
+ assert_eq!(r.area(), 30 * 20);
+ // let a = Rect::from(("a".to_string(), "b".to_string())).area(); // this doesn't work, because area() is not implemented for String
+ }
}