Macro forward

macro_rules! forward {
    ($( Self :: $method:ident ( self $( , $arg:ident : $ty:ty )* ) -> $ret:ty ; )*) => { ... };
    ($( $base:ident :: $method:ident ( self $( , $arg:ident : $ty:ty )* ) -> $ret:ty ; )*) => { ... };
    ($( $base:ident :: $method:ident ( $( $arg:ident : $ty:ty ),* ) -> $ret:ty ; )*) => { ... };
    ($( $imp:path as $method:ident ( self $( , $arg:ident : $ty:ty )* ) -> $ret:ty ; )*) => { ... };
}

Forward a method to an inherent method or a base trait method.