[shepmaster]

Yes, `&*foo` is meaningful. For example, `Vec<T>` becomes `[T]` and then `&[T]`.

Yes, a `Box<dyn Error>` is about the most rudimentary way of returning an arbitrary error, but it’s better than a panic or a sentinel value.

[nick__m]

Your example is not what the dbus crate does, in your case everything is related to T, it doesn't surprise!

In that crate the &*msg.interface().unwrap() magically become an &str !

[shepmaster]

I don’t know the dbus crate, so I’m not trying to say anything about that crate’s usage, I’m simply saying that referencing after dereferencing is idiomatic Rust.

For example, the standard library `String` type dereferences to `str` which you can then re-reference to `&str`.

[nick__m]

Sorry, I should have been clearer in my question, I wanted to know about A deref to B re-ref to &B.

ameliaquining awnsered my question and you modulated my opinion, that pattern is can be idiomatic when the principle of minimal surprises is respected.