From 6c66eaa035e5fc47ebbff44b81d2cb3cf1d7d568 Mon Sep 17 00:00:00 2001 From: Matthew Piziak Date: Thu, 18 Aug 2016 16:54:33 -0400 Subject: [PATCH] replace `AddAssign` example with something more evocative of addition This is analogous to PR #35709 for the `Add` trait. --- src/libcore/ops.rs | 31 +++++++++++++++++++++---------- 1 file changed, 21 insertions(+), 10 deletions(-) diff --git a/src/libcore/ops.rs b/src/libcore/ops.rs index 9347ac2a8c82f..1a203a898f73e 100644 --- a/src/libcore/ops.rs +++ b/src/libcore/ops.rs @@ -894,25 +894,36 @@ shr_impl_all! { u8 u16 u32 u64 usize i8 i16 i32 i64 isize } /// /// # Examples /// -/// A trivial implementation of `AddAssign`. When `Foo += Foo` happens, it ends up -/// calling `add_assign`, and therefore, `main` prints `Adding!`. +/// This example creates a `Point` struct that implements the `AddAssign` +/// trait, and then demonstrates add-assigning to a mutable `Point`. /// /// ``` /// use std::ops::AddAssign; /// -/// struct Foo; +/// #[derive(Debug)] +/// struct Point { +/// x: i32, +/// y: i32, +/// } /// -/// impl AddAssign for Foo { -/// fn add_assign(&mut self, _rhs: Foo) { -/// println!("Adding!"); +/// impl AddAssign for Point { +/// fn add_assign(&mut self, other: Point) { +/// *self = Point { +/// x: self.x + other.x, +/// y: self.y + other.y, +/// }; /// } /// } /// -/// # #[allow(unused_assignments)] -/// fn main() { -/// let mut foo = Foo; -/// foo += Foo; +/// impl PartialEq for Point { +/// fn eq(&self, other: &Self) -> bool { +/// self.x == other.x && self.y == other.y +/// } /// } +/// +/// let mut point = Point { x: 1, y: 0 }; +/// point += Point { x: 2, y: 3 }; +/// assert_eq!(point, Point { x: 3, y: 3 }); /// ``` #[lang = "add_assign"] #[stable(feature = "op_assign_traits", since = "1.8.0")]