Add support for HEAD method – #[head("/")]

[manifest]

It is currently impossible to define a handler for HEAD method.

impl MyApp {
    #[head("/")]
    fn index(&self) -> Result<String, ()> {
    // implementation
    }
}

[carllerche]

Additionally, HEAD requests should probably match GET as well.

[manifest]

Could you please elaborate on how you see this working? Both methods definitely work with the same resource but responses are different, so should be handlers.