Macro lock_free_static 

macro_rules! lock_free_static {
    ($(#[$attr:meta])* $vis:vis static $ident:ident: $ty:ty = $expr:expr; $($next:tt)*) => { ... };
    ($(#[$attr:meta])* $vis:vis static mut $ident:ident: $ty:ty = $expr:expr; $($next:tt)*) => { ... };
    () => { ... };
}

Convenience macro for creating lock-free statics.