macro_rules! using { ($($v:vis $p:ident),*) => { ... }; }
Declares a mod and uses it.
mod
using!{ pub mod1, pub(crate) mod2, mod3 }
Expands to:
mod mod1; pub use self::mod1::*; mod mod2; pub(crate) use self::mod2::*; mod mod3; use self::name::*;