Macro jxl_bitstream::define_bundle

macro_rules! define_bundle {
    (
        $(
            $(#[$attrs:meta])*
            $v:vis struct $bundle_name:ident
            $(aligned($aligned:literal))?
            $(ctx($ctx_id:ident : $ctx:ty))?
            $(error($err:ty))?
            {
                $($body:tt)*
            }
        )*
    ) => { ... };
}