//@ run-pass
#![allow(unused_variables)]
//@ pretty-expanded FIXME #23616
struct Bencher;
// ICE
fn warm_up<'a, F>(f: F) where F: Fn(&'a mut Bencher) {
}
fn main() {
// ICE trigger
warm_up(|b: &mut Bencher| () );
// OK
warm_up(|b| () );