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Clarified shadowing example #30447

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Dec 18, 2015
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Clarified shadowing example #30447

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10 changes: 6 additions & 4 deletions src/doc/book/patterns.md
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Original file line number Diff line number Diff line change
Expand Up @@ -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 {
Expand All @@ -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

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