Calling a closure stored in a struct, a bug or just a bad error message

[dutt]

I tried to do this:

struct S {
    x : uint,
    func : fn(uint)
}

impl S {
    fn no_func(val : uint) { println!("{}", val); }
    fn new() -> S {
        S { x : 0, func : S::no_func }
    }
}

fn main() {
    let s : S = S::new();
    s.func(7);
}

And I got the error:
error: typeSdoes not implement any method in scope named "func"

It seems to try to look for a member function and ignore the member variable. One person(alexchandel) in the rust irc channel said this was a bug and should work, another(p1start) said the error message should be improved.

[aochagavia]

To get this working, you need to write (s.func)(7);. The problem is that Rust will search only for methods named func and not for fields. I don't know if there are plans of changing this behavior. If not, then I guess it would be nice to get a clearer error message which explains this.

[huonw]

I've tagged the bug so that it covers improving the error message by adding something like note: write (s.func)(...)if you meant to call the function stored in thefunc field.

[aochagavia]

@huonw I guess we would need to check here if the type has a field with the same name as the method.

[dutt]

@aochagavia I got it working with the nice people in the channel but thanks anyway.

@huonw Alright, sounds good.