tests/ui/closures/nested-closure-escape-borrow.rs

//! regression test for <https://github.com/rust-lang/rust/issues/49824>
fn main() {
    let mut x = 0;
    || {
        || {
        //~^ ERROR captured variable cannot escape `FnMut` closure body
            let _y = &mut x;
        }
    };
}