rust/src/test/ui/error-codes/E0393.stderr

error[E0393]: the type parameter `T` must be explicitly specified
  --> $DIR/E0393.rs:13:43
   |
LL | fn together_we_will_rule_the_galaxy(son: &A) {}
   |                                           ^ missing reference to `T`
   |
   = note: because of the default `Self` reference, type parameters must be specified on object types

error: aborting due to previous error

If you want more information on this error, try using "rustc --explain E0393"