Macro numid::numid

macro_rules! numid {
    ($(#[$attr:meta])* $vis:vis struct $name:ident) => { ... };
    ($(#[$attr:meta])* $vis:vis struct $name:ident -> $init_val:expr) => { ... };
    ($(#[$attr:meta])* $vis:vis struct $name:ident($ty:ty)) => { ... };
    ($(#[$attr:meta])* $vis:vis struct $name:ident($ty:ty) -> $init_val:expr) => { ... };
}