RE: Re: union type is evil, redux

the crashes tend to occur in random places. they vary from one build to the next. often in pdump. vc++ does crash somewhere in pdump, in differing places from build to build. compiling sans union type makes the problem disappear. once i tracked the problem down and it was that gcc did not do structure assignments completely in parallel in all situations. with sufficiently complicated expressions of the form x = f(x), where x is a structure, it would sometimes think that it had correctly computed one of the fields, and assign it a value, when in fact the old value was still needed elsewhere in the expression. i wrote to the gcc developers and they got very defensive and quoted a section of the ansi standard, saying "well, we agree your expected behavior is reasonable but *technically* it's not required by the ansi standard." this only happened with mule and error-checking, because the expression was much more complicated that way. by rewriting it using temporaries, the problem went away.