Macro entry 

macro_rules! entry {
    ($($entry:ident => $body:stmt;)*) => { ... };
    (@internal initialize $body:stmt) => { ... };
    (@internal opcontrol $body:stmt) => { ... };
    (@internal autonomous $body:stmt) => { ... };
    (@internal disabled $body:stmt) => { ... };
    (@internal $invalid:ident $body:stmt) => { ... };
}

A safe wrapper for entry function definitions