## Keyboard shortcuts

Press `←` or `→` to navigate between chapters

Press `S` or `/` to search in the book

Press `?` to show this help

Press `Esc` to hide this help

# Error code E0730

An array without a fixed length was pattern-matched.

Erroneous code example:

    #![allow(unused)]
    fn main() {
    fn is_123<const N: usize>(x: [u32; N]) -> bool {
        match x {
            [1, 2, ..] => true, // error: cannot pattern-match on an
                                //        array without a fixed length
            _ => false
        }
    }
    }

To fix this error, you have two solutions:

1. Use an array with a fixed length.
2. Use a slice.

Example with an array with a fixed length:

    #![allow(unused)]
    fn main() {
    fn is_123(x: [u32; 3]) -> bool { // We use an array with a fixed size
        match x {
            [1, 2, ..] => true, // ok!
            _ => false
        }
    }
    }

Example with a slice:

    #![allow(unused)]
    fn main() {
    fn is_123(x: &[u32]) -> bool { // We use a slice
        match x {
            [1, 2, ..] => true, // ok!
            _ => false
        }
    }
    }