Macro define_dary_heap 

macro_rules! define_dary_heap {
    (
        $name:ident,
        $doc:literal,
        $value:ty,
        $storage:ty,
        $branch:expr,
        $block:ty
        , encode = $encode:expr
        , decode = $decode:expr
        $(, $field:ident: $field_type:ty = $field_value:expr)*
        $(,)?
    ) => { ... };
}