error[E0277]: the trait bound `fn() -> impl T<O = ()> {foo}: T` is not satisfied
  --> $DIR/fn-ctor-passed-as-arg-where-it-should-have-been-called.rs:17:9
   |
LL |     bar(foo);
   |     --- ^^^ the trait `T` is not implemented for fn item `fn() -> impl T<O = ()> {foo}`
   |     |
   |     required by a bound introduced by this call
   |
note: required by a bound in `bar`
  --> $DIR/fn-ctor-passed-as-arg-where-it-should-have-been-called.rs:14:16
   |
LL | fn bar(f: impl T<O=()>) {}
   |                ^^^^^^^ required by this bound in `bar`
help: use parentheses to call this function
   |
LL |     bar(foo());
   |            ++

error[E0277]: the trait bound `{closure@$DIR/fn-ctor-passed-as-arg-where-it-should-have-been-called.rs:18:19: 18:21}: T` is not satisfied
  --> $DIR/fn-ctor-passed-as-arg-where-it-should-have-been-called.rs:19:9
   |
LL |     bar(closure);
   |     --- ^^^^^^^ the trait `T` is not implemented for closure `{closure@$DIR/fn-ctor-passed-as-arg-where-it-should-have-been-called.rs:18:19: 18:21}`
   |     |
   |     required by a bound introduced by this call
   |
note: required by a bound in `bar`
  --> $DIR/fn-ctor-passed-as-arg-where-it-should-have-been-called.rs:14:16
   |
LL | fn bar(f: impl T<O=()>) {}
   |                ^^^^^^^ required by this bound in `bar`
help: use parentheses to call this closure
   |
LL |     bar(closure());
   |                ++

error: aborting due to 2 previous errors

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