Some more questions

[Manishearth]

I occasionally tweet rust quiz questions like these, see https://twitter.com/search?q=from%3Amanishearth%20quiz

Feel free to steal them 😄 (I may make a PR at some point)

[dtolnay]

Thanks! https://twitter.com/ManishEarth/status/823342219369201664 would be great.

[dtolnay]

Here is a wild one for you that I can't make into a quiz question but fits your style better:

fn main() {
    let x: String;
    let m!() = x;
}

• always compile error?
• sometimes compile error?

If you have:

macro_rules! m {
    () => { _ };
}

then this compiles (for some reason).