Although the Badge pattern makes it flexible to add functions with different badges, this one doesn't have the awkward interface: https://godbolt.org/z/25k1DG

Although the Badge pattern makes it flexible to add functions with different badges, this one doesn't have the awkward interface: https://godbolt.org/z/25k1DG https://godbolt.org/z/25k1DG It just makes use of the non-transitiveness of friend.