// Tests that we don't allow unconstrained lifetime parameters in impls when // the lifetime is used in an associated opaque type. #![feature(type_alias_impl_trait)] trait UnwrapItemsExt { type Iter; fn unwrap_items(self) -> Self::Iter; } struct MyStruct {} trait MyTrait<'a> {} impl<'a> MyTrait<'a> for MyStruct {} impl<'a, I> UnwrapItemsExt for I { //~^ ERROR the lifetime parameter `'a` is not constrained type Iter = impl MyTrait<'a>; fn unwrap_items(self) -> Self::Iter { MyStruct {} } } fn main() {}