### What it does
Checks for `match vec[idx]` or `match vec[n..m]`.

### Why is this bad?
This can panic at runtime.

### Example
```
let arr = vec![0, 1, 2, 3];
let idx = 1;

match arr[idx] {
    0 => println!("{}", 0),
    1 => println!("{}", 3),
    _ => {},
}
```

Use instead:
```
let arr = vec![0, 1, 2, 3];
let idx = 1;

match arr.get(idx) {
    Some(0) => println!("{}", 0),
    Some(1) => println!("{}", 3),
    _ => {},
}
```