Macro impl_compare_equality_idx

macro_rules! impl_compare_equality_idx {
    ($($ty:ident $ret:ident
                $cmpeq:ident $cmpne:ident
                $cmpeq_or_0:ident $cmpne_or_0:ident
                $cmpeq_cc:ident $cmpne_cc:ident
                $cmpeq_or_0_cc:ident $cmpne_or_0_cc:ident
        )*) => { ... };
}