Comment by astrobe_

It looks more like an implementation error to me, and actually it looks more like a design mistake than an implementation choice because there are arguments in favor of using an abstract functor class for the comparison function (you'll need a closure sooner or later), which would have given the chance to warn the user about this particular issue in the docs - at least it would have been more visible and clearer than it currently is [1].

Because until vibe coding becomes a culture, programmers are at least expected to "RTFM". But that's also a requirement which is becoming harder to meet by the year, because - you almost said it the first few minutes of your talk - "we needed to merge it ASAP".

This mistake seems to have been somewhat fixed in C++20 [2]. "Too little too late", yes, probably.

[1] https://en.cppreference.com/w/cpp/algorithm/sort.html

[2] ibidem, tacit use of std::less.