1 #![feature(type_alias_impl_trait)]
3 type Foo = impl std::fmt::Debug;
5 fn foo(b: bool) -> Foo {
9 std::iter::empty().collect()
13 type Bar = impl std::fmt::Debug;
15 fn bar(b: bool) -> Bar {
19 std::iter::empty().collect()
20 //~^ ERROR a value of type `Bar` cannot be built from an iterator over elements of type `_`