Unused type alias does not produce warning

[matthew-piziak]

I created the following main.rs:

type Unused = String;

fn main() {
    println!("Hello, world!");
}

Note that Unused is not pub and not used. Nevertheless no "unused" warning is given.

Here is the full (empty) output of cargo build:

Finished debug [unoptimized + debuginfo] target(s) in 0.0 secs