if anyone
here has any opinions about whether ==/!=/<=> is useful on the container
level (ordered or unordered), please chime in.
I cannot think of any use I'd have of such comparisons, except for niche cases where I'd happily just iterate (e.g. tests).
Based on that, and that alone, I'd go for the no built-in comparison route for now, with the option of adding one later if a solid use case comes along.
That is, unless a plan involves storing some composable hash in each block (customising by template args might give the user choice of ordered/unordered comparisons? Not sure on that one, just spitballing), in which case ABI prevents the later change.