error[E0790]: cannot call associated function on trait without specifying the corresponding `impl` type
  --> $DIR/issue-104328.rs:10:5
   |
LL |     fn f() {}
   |     --------- `Foo::f` defined here
...
LL |     Foo::f();
   |     ^^^^^^ cannot call associated function of trait
   |
help: use the fully-qualified path to the only available implementation
   |
LL |     <(dyn Sized + 'static) as Foo>::f();
   |     +++++++++++++++++++++++++    +

error: aborting due to previous error

For more information about this error, try `rustc --explain E0790`.