server() -> impl1fn server() -> impl { 2 //~^ ERROR at least one trait must be specified 3 ().map2(|| "") 4 } 5 6 trait FilterBase2 { map2<F>(self, f: F) -> Map2<F>7 fn map2<F>(self, f: F) -> Map2<F> {} 8 //~^ ERROR mismatched types 9 //~^^ ERROR the size for values of type `Self` cannot be known at compilation time 10 } 11 12 struct Map2<Segment2> { 13 _func: F, 14 //~^ ERROR cannot find type `F` in this scope 15 } 16 17 impl<F> FilterBase2 for F {} 18 main()19fn main() {} 20