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From: Jonathan Wakely <jwakely.gcc@gmail.com>
Date: Thu, 05 Dec 2019 22:37:00 -0000
Message-ID: <CAH6eHdTQey6+Mn7Ms1w1TM7TCxw8teEg5D0qWYD7Bb3TLMafrw@mail.gmail.com>
Subject: 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)
To: Segher Boessenkool <segher@kernel.crashing.org>
Cc: Michael Matz <matz@suse.de>, Thomas Schwinge <thomas@codesourcery.com>, 	"gcc@gcc.gnu.org" <gcc@gcc.gnu.org>, gcc-patches <gcc-patches@gcc.gnu.org>, 	"fortran@gcc.gnu.org List" <fortran@gcc.gnu.org>
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On Thu, 5 Dec 2019 at 22:19, Segher Boessenkool wrote:
> Or you could write
>
>     auto __c = (__builtin_memcmp(&*__first1, &*__first2, __len) <=> 0);
>     if (__c)
>       return __c;
>
> which is much easier to read, to my eyes anyway.  And it is exactly the
> same for the compiler.

In this case yes, but not in general.

Given:

auto x = foo();
if (bar(x))
{ }
some_type y;

The destructor of x won't run until after y has been destroyed. That's
not at all identical to:

if (auto x = foo(); bar(x))
{ }
some_type y;

Please don't try to tell me how C++ works :-)