Macro grade::__build_func

macro_rules! __build_func {
    ($parent:ident, [$pack_func:ident $(,$pack_arg:expr)*], $child:ident$(:$child_alias:ident)? {$($child_body:tt)*}) => { ... };
    ($parent:ident, $child:ident$(:$child_alias:ident)? {$($child_body:tt)*}) => { ... };
}