Your assessment is completely, totally, and verifiably wrong. It's obnoxious, but not surprising, how many commenters have chimed in with "program has bug BLAH"

Your assessment is completely, totally, and verifiably wrong. It's obnoxious, but not surprising, how many commenters have chimed in with "program has bug BLAH" when they provably did not try to run the program themselves. Because if you did attempt to run the program you'd find that changing numThreads to a constexpr makes no difference.