$ cargo run
   Compiling traits-example v0.1.0 (file:///projects/traits-example)
error[E0283]: type annotations needed
  --> src/main.rs:20:43
   |
2  |     fn baby_name() -> String;
   |     ------------------------- required by `Animal::baby_name`
...
20 |     println!("A baby dog is called a {}", Animal::baby_name());
   |                                           ^^^^^^^^^^^^^^^^^ cannot infer type
   |
   = note: cannot satisfy `_: Animal`

error: aborting due to previous error

For more information about this error, try `rustc --explain E0283`.
error: could not compile `traits-example`

To learn more, run the command again with --verbose.
