Macro sugars::cset

macro_rules! cset {
    ($($tokens: tt)+) => { ... };
}

Build HashSet from collection iterator comprehensions.

Limitations

• Only 3 nested comprehensions

Examples:

use sugars::cset;

let w = cset!{x; x in 1..10};
let z = cset!{x; x in 1..10, if x%2 == 0};