rust/tests/ui/closures/2229_closure_analysis/run_pass/multivariant.rs

// Test precise capture of a multi-variant enum (when remaining variants are
// visibly uninhabited).
//@ revisions: normal exhaustive_patterns
//@ edition:2021
//@ run-pass
#![cfg_attr(exhaustive_patterns, feature(exhaustive_patterns))]
#![feature(never_type)]

pub fn main() {
    let mut r = Result::<!, (u32, u32)>::Err((0, 0));
    let mut f = || {
        let Err((ref mut a, _)) = r;
        *a = 1;
    };
    let mut g = || {
        let Err((_, ref mut b)) = r;
        *b = 2;
    };
    f();
    g();
    assert_eq!(r, Err((1, 2)));
}