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Re: [RFC] Characters per line: from punch card (80) to line printer (132) (was: [Patch][OpenMP/OpenACC/Fortran] Fix mapping of optional (present|absent) arguments)
On Thu, Dec 05, 2019 at 02:06:50PM -0600, Segher Boessenkool wrote:
> On Thu, Dec 05, 2019 at 05:03:43PM +0000, Jonathan Wakely wrote:
> > C++17 introduces a nice feature, with rationale similar to declaring
> > variables in a for-loop init-statement:
> > if (auto var = foo(); bar(var))
> Similar to GNU C statement expressions, which are *also* only a good
> idea to use in limited cases.
> > The variable is only in scope for the block where you need it, just
> > like a for-loop.
> > Unfortunately nearly every time I've tried to use this recently, I've
> > found it's impossible in 80 columns, e.g. this from yesterday:
> > if (auto __c = __builtin_memcmp(&*__first1, &*__first2, __len) <=>
> > 0; __c != 0)
> > return __c;
> > When you're forced to uglify every variable with a leading __ you run
> > out of characters pretty damn quickly.
> If using this "nice feature" forces you to uglify your code, then maybe
> it is not such a nice feature, and you should not use it.
I disagree, it is a nice feature, without quotes. It's Good Style not to
leak variables into enclosing scopes.
> If you have issues with scoping your functions are WAY too long already.
I don't think that's the case here.
Marek Polacek • Red Hat, Inc. • 300 A St, Boston, MA