Macro lazy_static

macro_rules! lazy_static {
    ($(#[$attr:meta])* static ref $N:ident : $T:ty = $e:expr; $($t:tt)*) => { ... };
    ($(#[$attr:meta])* pub static ref $N:ident : $T:ty = $e:expr; $($t:tt)*) => { ... };
    ($(#[$attr:meta])* pub ($($vis:tt)+) static ref $N:ident : $T:ty = $e:expr; $($t:tt)*) => { ... };
    () => { ... };
}