The default operators are very cool, but I assume that many codebases would ban them.
Imagine, for example, an engineer decided to reorder members in a struct to make it pack better. Now the semantics of default <=> have changed!
Also, as a minor nit, the optional number sample has a possible bug. I would assume that two null optionals would compare equivalently. Or is that part of how <=> should work? Should NaN <=> NaN == partial_ordering::unordered?
Imagine, for example, an engineer decided to reorder members in a struct to make it pack better. Now the semantics of default <=> have changed!
Also, as a minor nit, the optional number sample has a possible bug. I would assume that two null optionals would compare equivalently. Or is that part of how <=> should work? Should NaN <=> NaN == partial_ordering::unordered?