error[E0277]: the trait bound `{float}: Foo` is not satisfied
  --> $DIR/type_wf.rs:18:13
   |
LL | struct S<T: Foo> {
   | ---------------- required by `S`
...
LL |     let s = S {
   |             ^ the trait `Foo` is not implemented for `{float}`
   |
   = help: the following implementations were found:
             <Option<T> as Foo>
             <i32 as Foo>

error: aborting due to previous error

For more information about this error, try `rustc --explain E0277`.