user0/rust
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Clarified shadowing example

Browse source 
Added some additional descriptive sentences and changed x to an int in
the example
This commit is contained in:
Xmasreturns 2015-12-17 13:05:00 -08:00
parent 6734dccc31
commit 2a23e4a5b0
1 changed files with 6 additions and 4 deletions
Download patch file Download diff file Expand all files Collapse all files

10
src/doc/book/patterns.md
View file

@ -27,7 +27,7 @@ There’s one pitfall with patterns: like anything that introduces a new binding
they introduce shadowing. For example:
```rust
let x = 'x';
let x = 1;
let c = 'c';
match c {
@ -41,12 +41,14 @@ This prints:
```text
x: c c: c
x: x
x: 1
```
In other words, `x =>` matches the pattern and introduces a new binding named
`x` that’s in scope for the match arm. Because we already have a binding named
`x`, this new `x` shadows it.
`x`. This new binding is in scope for the match arm and takes on the value of
`c`. Notice that the value of `x` outside the scope of the match has no bearing
on the value of `x` within it. Because we already have a binding named `x`, this
new `x` shadows it.
# Multiple patterns