Autocomplete for types with type constraints

Probably it hasn’t been implemented yet but I’ve decided to open the issue anyway.

Example:

fn main() {
    println!("{:?}", foo()./* autocomplete here */);
}

fn foo() -> Result<i32, i32> {
    Ok(42)
}

Autocomplete works for methods on impl<T, E> Result<T, E> but doesn’t work on impl<T, E> Result<T, E> where E: Debug and bunch of others with type constraints, i.e. doesn’t autocomplete unwrap, expect, etc.

[matklad]

Hm, I wonder if we should be less conservative here and just resolve all methods regardless of trait bouds.

We’ll use trait bounds to disambiguate possible conflicts and (somewhere in the future), to annotate errors like “you are calling .contains_key on BTreeMap, but Key is not Hash. Add #[derive(Hash)]?”

[farodin91]

@matklad I would prefer your idea. For example

let mut map = HashMap::new();
                     \\^unresolved

At this point, intellij can’t know type constraints.