Macro literally::hset

macro_rules! hset {
    (@single $($x:tt)*) => { ... };
    (@count $($rest:expr),*) => { ... };
    ($($key:expr,)+) => { ... };
    ($($key:expr),*) => { ... };
}

Literally just a HashSet literal with values into'd.

let s: HashSet<String> = hset!{ "value" };
assert_eq!(s.get("value"), Some(&"value".to_string()))