1 use std::fmt::Debug; 2 foo(x: impl Debug, y: impl Debug) -> String3fn foo(x: impl Debug, y: impl Debug) -> String { 4 let mut a = x; 5 a = y; //~ ERROR mismatched 6 format!("{:?}", a) 7 } 8 9 trait S<T> {} 10 much_universe<T: S<impl Debug>, U: IntoIterator<Item = impl Iterator<Item = impl Clone>>>( _: impl Debug + Clone, )11fn much_universe<T: S<impl Debug>, U: IntoIterator<Item = impl Iterator<Item = impl Clone>>>( 12 _: impl Debug + Clone, 13 ) { 14 } 15 main()16fn main() {} 17