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# Error code E0409

An "or" pattern was used where the variable bindings are not consistently bound across patterns.

Erroneous code example:

    #![allow(unused)]
    fn main() {
    let x = (0, 2);
    match x {
        (0, ref y) | (y, 0) => { /* use y */} // error: variable `y` is bound with
                                              //        different mode in pattern #2
                                              //        than in pattern #1
        _ => ()
    }
    }

Here, `y` is bound by-value in one case and by-reference in the other.

To fix this error, just use the same mode in both cases. Generally using `ref` or `ref mut` where not already used will fix this:

    #![allow(unused)]
    fn main() {
    let x = (0, 2);
    match x {
        (0, ref y) | (ref y, 0) => { /* use y */}
        _ => ()
    }
    }

Alternatively, split the pattern:

    #![allow(unused)]
    fn main() {
    let x = (0, 2);
    match x {
        (y, 0) => { /* use y */ }
        (0, ref y) => { /* use y */}
        _ => ()
    }
    }