### What it does
Checks for match which is used to add a reference to an
`Option` value.

### Why is this bad?
Using `as_ref()` or `as_mut()` instead is shorter.

### Example
```
let x: Option<()> = None;

let r: Option<&()> = match x {
    None => None,
    Some(ref v) => Some(v),
};
```

Use instead:
```
let x: Option<()> = None;

let r: Option<&()> = x.as_ref();
```