As part of my code auditing classes in the mid-2000s, we had an exercise of auditing the ISO C standard for ambiguities that may lead to errors. One component of this was grepping for “undefined” and then seeing if that was likely to be interesting. But my favorite was auditing..
descriptions of standard library functions. Fgets() description was “reads at most one less than size bytes” - and lo and behold, several libcs of the era would malfunction badly on fgets with zero sizes.
I have always been meaning to do a round of this with the C++ standard.
