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revised pointer example

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This commit is contained in:
Junseok Lee 2015-02-17 18:05:15 -08:00
parent dfc5c0f1e8
commit 8e0e87fc32
1 changed files with 14 additions and 13 deletions
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27
src/doc/trpl/pointers.md
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@ -361,16 +361,16 @@ duration a *lifetime*. Let's try a more complex example:
```{rust}
fn main() {
let x = &mut 5;
let mut x = 5;
if *x < 10 {
if x < 10 {
let y = &x;
println!("Oh no: {}", y);
return;
}
*x -= 1;
x -= 1;
println!("Oh no: {}", x);
}
@ -382,17 +382,18 @@ mutated, and therefore, lets us pass. This wouldn't work:
```{rust,ignore}
fn main() {
let x = &mut 5;
let mut x = 5;
if *x < 10 {
if x < 10 {
let y = &x;
*x -= 1;
x -= 1;
println!("Oh no: {}", y);
return;
}
*x -= 1;
x -= 1;
println!("Oh no: {}", x);
}
@ -401,12 +402,12 @@ fn main() {
It gives this error:
```text
test.rs:5:8: 5:10 error: cannot assign to `*x` because it is borrowed
test.rs:5 *x -= 1;
^~
test.rs:4:16: 4:18 note: borrow of `*x` occurs here
test.rs:4 let y = &x;
^~
test.rs:7:9: 7:15 error: cannot assign to `x` because it is borrowed
test.rs:7 x -= 1;
^~~~~~
test.rs:5:18: 5:19 note: borrow of `x` occurs here
test.rs:5 let y = &x;
^
```
As you might guess, this kind of analysis is complex for a human, and therefore