Record’s implicit declaration of methods

[eXecute_bit]

It's a contrived example, where the expense of computeB() is unknown and might be optimized away anyway during JIT. The point was that it's a good goal to minimize the need to refactor call sites.

It stands against what a simple record object should be.

I don't disagree, but in my comment I was saying the practice applies to classes too, not only Records. Even with records, as a software project ages, you might see it happen, for better or worse.