Infinite loop in macro expansion

[nikomatsakis]

This program (which, as far as I can tell, is ok?) seems to loop infinitely:

fn macros() {
    macro_rules! if_ok(
        ($inp: expr) => (
            match $inp {
                Ok(move v) => { move v }
                Err(move e) => { return Err(e); }
            }
        )
    );
}

fn main() {
    let r = Ok(2);
    let p = if_ok!(move r);
    assert p == 2;
}

[paulstansifer]

I wasn't able to get it to compile as-is (it needed a definition for Ok and Err, and to be called in a function that could return Err(...), so I changed it to the following. However, it now Works For Me™; perhaps it's been fixed?

enum Result {
    Ok(int), Err(int)
}

fn macros() {
    macro_rules! if_ok(
        ($inp: expr) => (
            match $inp {
                Ok(move v) => { move v }
                Err(move e) => { return Err(e); }
            }
        )
    );
}

fn f() -> Result {
    let r = Ok(2);
    let p = if_ok!(move r);
    assert p == 2;
    return Ok(p);
}

fn main() {
    f();
}

[nikomatsakis]

this was user error on my part, I thought I closed this bug a long time ago!