// Regression test for https://github.com/rust-lang/rust/issues/121508. struct Struct(T); impl std::ops::Deref for Struct { type Target = dyn Fn(T); fn deref(&self) -> &assert_mem_uninitialized_valid::Target { //~^ERROR: use of unresolved module or unlinked crate unimplemented!() } } fn main() { let f = Struct(Default::default()); f(0); f(0); }