pub trait Foo { type T; } impl Foo for i32 { type T = f32; } pub struct U<T1, T2>(T1, S<T2>) where T1: Foo<T = T2>; pub struct S<T>(T); fn main() { // The error message here isn't great -- it has to do with the fact that the // `expected_inputs_for_expected_output` deduced inputs differs from the inputs // that we infer from the constraints of the signature. // // I am not really sure what the best way of presenting this error message is, // since right now it just suggests changing `3u32` <=> `3f32` back and forth. let _: U<_, u32> = U(1, S(3u32)); //~^ ERROR mismatched types //~| ERROR mismatched types }