impl Ignorable for Vec?

[timmc]

Would it make sense to make Vec implement Ignorable? Right now only Option and Result are Ignorable: https://api.rocket.rs/v0.5/rocket/http/uri/fmt/trait.Ignorable

It would be great if I could pass uri!(my_route(things = _)) when things: Vec<_> -- especially because I can't just use vec![]; I need to specify type annotations: uri!(my_route(things = Vec::<Thing>::new())). It's kind of annoying and doesn't let me easily read it as "oh, I just want the default value here".

For that matter, should there be a blanket implementation for Default?

[the10thWiz]

I think this does make sense for Vec<T>, since the default would be empty.

I don't think it makes sense as a blanket implementation for Default, since it's more complex than that. What it's supposed to express is that the field will be omitted by the uri! macro - e.g. the following code snippet would produce a uri of /item/100?.

#[get("/item/<id>?<track>")]
fn get_item(id: i32, track: Option<u8>) { /* .. */ }

uri!(get_item(id = 100, track = _));

A PR to add a Ignorable impl for Vec<T> would be accepted.