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From: "frankhb1989 at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c++/67795] Wrong code generated for conditional expression with cast
Date: Thu, 01 Oct 2015 13:06:00 -0000	[thread overview]
Message-ID: <bug-67795-4-diZfLQBPM1@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-67795-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67795

--- Comment #8 from frankhb1989 at gmail dot com ---
(In reply to Markus Trippelsdorf from comment #4)
> Return by value if you want to avoid undefined behavior.

No. This is not the point. For something like 'std::move' or 'std::forward',
can you suggest such change?

The code of the case is reduced from a function template which return 'S&&',
where 'S' is a template type parameter (and 'S&&' is also in function parameter
list for perfect forwarding). Simply returning object type is not acceptable in
the original case because: 1. Even move construction for 'S' is not guaranteed
to be zero overhead. 2.It needs one more static_cast/std::move in many places
of the the client code which makes it bloat A LOT.


  parent reply	other threads:[~2015-10-01 13:06 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-10-01 10:52 [Bug c++/67795] New: " frankhb1989 at gmail dot com
2015-10-01 11:14 ` [Bug c++/67795] " trippels at gcc dot gnu.org
2015-10-01 12:28 ` frankhb1989 at gmail dot com
2015-10-01 12:42 ` frankhb1989 at gmail dot com
2015-10-01 12:52 ` rguenth at gcc dot gnu.org
2015-10-01 12:56 ` frankhb1989 at gmail dot com
2015-10-01 12:57 ` glisse at gcc dot gnu.org
2015-10-01 13:06 ` frankhb1989 at gmail dot com [this message]
2015-10-01 13:09 ` frankhb1989 at gmail dot com
2015-10-01 13:13 ` frankhb1989 at gmail dot com
2021-10-11  1:50 ` pinskia at gcc dot gnu.org
2021-12-09  9:12 ` marxin at gcc dot gnu.org
2022-02-01 15:56 ` marxin at gcc dot gnu.org

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