From 42cbd7a9bd53f2eeb96c4416cffe9fd735da9039 Mon Sep 17 00:00:00 2001 From: Sean T Allen Date: Thu, 22 Jan 2015 13:00:15 -0500 Subject: [PATCH] Reference correct fn during lifetime ellision --- src/doc/trpl/ownership.md | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/src/doc/trpl/ownership.md b/src/doc/trpl/ownership.md index 8b7e37dd4c2..56cb5b1de69 100644 --- a/src/doc/trpl/ownership.md +++ b/src/doc/trpl/ownership.md @@ -244,8 +244,8 @@ three. The ownership system in Rust does this through a concept called Remember the function that borrowed an `i32`? Let's look at it again. ```rust -fn add_one(num: &i32) -> i32 { - *num + 1 +fn add_one(num: &mut i32) { + *num += 1; } ``` @@ -255,8 +255,8 @@ cover the others later. Without eliding the lifetimes, `add_one` looks like this: ```rust -fn add_one<'a>(num: &'a i32) -> i32 { - *num + 1 +fn add_one<'a>(num: &'a mut i32) { + *num += 1; } ``` @@ -278,12 +278,12 @@ fn add_two<'a, 'b>(...) Then in our parameter list, we use the lifetimes we've named: ```{rust,ignore} -...(num: &'a i32) -> ... +...(num: &'a mut i32) ``` -If you compare `&i32` to `&'a i32`, they're the same, it's just that the -lifetime `'a` has snuck in between the `&` and the `i32`. We read `&i32` as "a -reference to an i32" and `&'a i32` as "a reference to an i32 with the lifetime 'a.'" +If you compare `&mut i32` to `&'a mut i32`, they're the same, it's just that the +lifetime `'a` has snuck in between the `&` and the `mut i32`. We read `&mut i32` as "a +mutable reference to an i32" and `&'a mut i32` as "a mutable reference to an i32 with the lifetime 'a.'" Why do lifetimes matter? Well, for example, here's some code: -- 2.44.0