5 pub struct Foo<T>(pub T);
10 impl<T> Finish for T {}
11 impl Dt for &mut fmt::Formatter<'_> {}
14 fn field(&self, _: impl Sized) {
15 panic!("got into field");
19 fn finish(&self) -> Result<(), std::fmt::Error> {
20 panic!("got into finish");
24 fn debug_tuple(&self, _: &str) {
25 panic!("got into debug_tuple");
31 assert_eq!("Foo(())", format!("{:?}", foo));