On Wed, May 16, 2018 at 10:06 AM, bartc <b...@freeuk.com> wrote: > On 16/05/2018 16:09, Ian Kelly wrote: >> >> On Tue, May 15, 2018, 6:36 PM bartc <b...@freeuk.com> wrote: >> >>> On 16/05/2018 01:04, Steven D'Aprano wrote: >>> >>>> I'm not a C coder, but I think that specific example would be immune to >>>> the bug we are discussing, since (I think) you can't chain assignments >>>> in >>>> C. Am I right? >>> >>> >>> Assignments can be chained in C (with right-to-left precedence) as can >>> augmented assignments (+= and so on). >>> >> >> Yes, but not in the particular example that Steven was referring to, which >> you elided from your quoting. > > > I was responding to the chained assignment bit: > > a = b = c = d = x; > > is allowed, but (depending on implementation details), the first = might be > a different kind of assignment from the other three. > >> open(...) is not a valid LHS for assignment. > > > The LHS needs to be an lvalue. A function result by itself won't be. open() > would need to be a macro that expands to an lvalue, or used like this when > open() returns a pointer: > > a = *open() = x; > > So it only needs an extra * (subject to the correct types of everything > involved) for both these "=" to be plausible.
Sure, but that wasn't the example. The macro possibility is a good point, but that's technically the C preprocessor, not the C language itself. -- https://mail.python.org/mailman/listinfo/python-list
