Macro amiya::m

macro_rules! m {
    ($func: ident) => { ... };
    ($ctx: ident : $ex: ty => $body: block ) => { ... };
    ($ctx: ident : $ex: ty => $body: expr ) => { ... };
    ($ctx: ident => $body: block) => { ... };
    ($ctx: ident => $body: expr) => { ... };
}