Macro requirements 

macro_rules! requirements {
    (
        $(
            $vis:vis $name:ident : $kind:path {
                description: $desc:expr
                $(, $key:ident : $value:expr)* $(,)?
            }
        )*
    ) => { ... };
}

Define multiple requirements in a single block.

Delegates to requirement! for each entry.

qa::requirements! {
    pub REQ_A: Functional {
        description: "First requirement",
        source: "spec v1",
    }

    pub REQ_B: Safety {
        description: "Second requirement",
    }
}