From 6cd86b942012c98c645b975f398bd5253118e3e7 Mon Sep 17 00:00:00 2001
From: =?utf8?q?Tomas=20Wenstr=C3=B6m?= <tomas.wenstrom@gmail.com>
Date: Sat, 16 Jan 2021 13:59:40 +0100
Subject: [PATCH] Implement point operators with macro

---
 src/common.rs | 118 +++++++++++++++-------------------------------------------
 1 file changed, 29 insertions(+), 89 deletions(-)

diff --git a/src/common.rs b/src/common.rs
index f91ec83..c75274c 100644
--- a/src/common.rs
+++ b/src/common.rs
@@ -21,59 +21,38 @@ impl Point2D<f64> {
     }
 }
 
-////////// add point to point //////////////////////////////////////////////////
-impl<T: Add<Output = T>> Add for Point2D<T> {
-    type Output = Self;
-
-    fn add(self, rhs: Self) -> Self {
-        Self {
-            x: self.x + rhs.x,
-            y: self.y + rhs.y,
+macro_rules! point_op {
+    ($op:tt, $trait:ident($fn:ident), $trait_assign:ident($fn_assign:ident), $rhs:ident = $Rhs:ty => $x:expr, $y:expr) => {
+        impl<T: $trait<Output = T>> $trait<$Rhs> for Point2D<T> {
+            type Output = Self;
+
+            fn $fn(self, $rhs: $Rhs) -> Self {
+                Self {
+                    x: self.x $op $x,
+                    y: self.y $op $y,
+                }
+            }
         }
-    }
-}
-
-impl<T: Add<Output = T> + Copy> AddAssign for Point2D<T> {
-    fn add_assign(&mut self, rhs: Self) {
-	*self = Self {
-            x: self.x + rhs.x,
-            y: self.y + rhs.y,
-	}
-    }
-}
 
-////////// add tuple to point //////////////////////////////////////////////////
-impl<T: Add<Output = T>> Add<(T, T)> for Point2D<T> {
-    type Output = Self;
-
-    fn add(self, rhs: (T, T)) -> Self {
-        Self {
-            x: self.x + rhs.0,
-            y: self.y + rhs.1,
+        impl<T: $trait<Output = T> + Copy> $trait_assign<$Rhs> for Point2D<T> {
+            fn $fn_assign(&mut self, $rhs: $Rhs) {
+                *self = Self {
+                    x: self.x $op $x,
+                    y: self.y $op $y,
+                }
+            }
         }
     }
 }
 
-////////// subtract point from point ///////////////////////////////////////////
-impl<T: Sub<Output = T>> Sub for Point2D<T> {
-    type Output = Self;
-
-    fn sub(self, rhs: Self) -> Self {
-        Self {
-            x: self.x - rhs.x,
-            y: self.y - rhs.y,
-        }
-    }
-}
-
-impl<T: Sub<Output = T> + Copy> SubAssign for Point2D<T> {
-    fn sub_assign(&mut self, rhs: Self) {
-	*self = Self {
-            x: self.x - rhs.x,
-            y: self.y - rhs.y,
-	}
-    }
-}
+point_op!(+, Add(add), AddAssign(add_assign), rhs = Point2D<T> => rhs.x, rhs.y);
+point_op!(-, Sub(sub), SubAssign(sub_assign), rhs = Point2D<T> => rhs.x, rhs.y);
+point_op!(*, Mul(mul), MulAssign(mul_assign), rhs = Point2D<T> => rhs.x, rhs.y);
+point_op!(/, Div(div), DivAssign(div_assign), rhs = Point2D<T> => rhs.x, rhs.y);
+point_op!(+, Add(add), AddAssign(add_assign), rhs = (T, T) => rhs.0, rhs.1);
+point_op!(-, Sub(sub), SubAssign(sub_assign), rhs = (T, T) => rhs.0, rhs.1);
+point_op!(*, Mul(mul), MulAssign(mul_assign), rhs = (T, T) => rhs.0, rhs.1);
+point_op!(/, Div(div), DivAssign(div_assign), rhs = (T, T) => rhs.0, rhs.1);
 
 ////////// multiply point with scalar //////////////////////////////////////////
 impl<T: Mul<Output = T> + Copy> Mul<T> for Point2D<T> {
@@ -96,27 +75,6 @@ impl<T: Mul<Output = T> + Copy> MulAssign<T> for Point2D<T> {
     }
 }
 
-////////// multiply components of two points ///////////////////////////////////
-impl<T: Mul<Output = T>> Mul for Point2D<T> {
-    type Output = Self;
-
-    fn mul(self, rhs: Self) -> Self {
-	Self {
-	    x: self.x * rhs.x,
-	    y: self.y * rhs.y,
-	}
-    }
-}
-
-impl<T: Mul<Output = T> + Copy> MulAssign for Point2D<T> {
-    fn mul_assign(&mut self, rhs: Self) {
-	*self = Self {
-	    x: self.x * rhs.x,
-	    y: self.y * rhs.y,
-	}
-    }
-}
-
 ////////// divide point with scalar ////////////////////////////////////////////
 impl<T: Div<Output = T> + Copy> Div<T> for Point2D<T> {
     type Output = Self;
@@ -138,27 +96,6 @@ impl<T: Div<Output = T> + Copy> DivAssign<T> for Point2D<T> {
     }
 }
 
-////////// divide components of two points /////////////////////////////////////
-impl<T: Div<Output = T>> Div for Point2D<T> {
-    type Output = Self;
-
-    fn div(self, rhs: Self) -> Self {
-	Self {
-	    x: self.x / rhs.x,
-	    y: self.y / rhs.y,
-	}
-    }
-}
-
-impl<T: Div<Output = T> + Copy> DivAssign for Point2D<T> {
-    fn div_assign(&mut self, rhs: Self) {
-	*self = Self {
-	    x: self.x / rhs.x,
-	    y: self.y / rhs.y,
-	}
-    }
-}
-
 impl<T: Neg<Output = T>> Neg for Point2D<T> {
     type Output = Self;
 
@@ -236,6 +173,7 @@ mod tests {
         assert_eq!(a - point!(2, 2), point!(-1, -2));
         a -= point!(2, 2);
         assert_eq!(a, point!(-1, -2));
+        assert_eq!(point!(1, 0) - (2, 3), point!(-1, -3));
     }
 
     #[test]
@@ -247,6 +185,7 @@ mod tests {
         assert_eq!(a, point!(2, 4));
         a *= point!(3, 1);
         assert_eq!(a, point!(6, 4));
+        assert_eq!(point!(1, 0) * (2, 3), point!(2, 0));
     }
 
     #[test]
@@ -258,6 +197,7 @@ mod tests {
         assert_eq!(a, point!(2, 4));
         a /= point!(2, 4);
         assert_eq!(a, point!(1, 1));
+        assert_eq!(point!(6, 3) / (2, 3), point!(3, 1));
     }
 
     #[test]
-- 
2.11.0