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From: "alex-j-a at hotmail dot co.uk" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug libstdc++/64814] std::copy_n advances InputIterator one *less* time than necessary.
Date: Tue, 27 Jan 2015 16:40:00 -0000 [thread overview]
Message-ID: <bug-64814-4-Ue4Zyxlv6q@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-64814-4@http.gcc.gnu.org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64814
--- Comment #5 from Anquietas <alex-j-a at hotmail dot co.uk> ---
(In reply to Jonathan Wakely from comment #3)
> However, I don't see any requirement in the standard that says we're
> supposed to do so. All that is required is n assignments, there is no
> guarantee that the input range is also incremented past the last element
> written to.
The closest thing I could find to an up to date copy of the C++11 standard:
http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2012/n3337.pdf
copy_n is on page 851
"Effects: For each non-negative integer i < n, performs *(result + i) = *(first
+ i)."
Since it's talking about input iterators where (first + n) isn't valid I think
we can interpret this as n applications each of ++first and *first. I don't
know whether the most recent version changed the description though; perhaps if
you could provide a link?
next prev parent reply other threads:[~2015-01-27 16:40 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-01-27 3:49 [Bug libstdc++/64814] New: " alex-j-a at hotmail dot co.uk
2015-01-27 11:28 ` [Bug libstdc++/64814] " redi at gcc dot gnu.org
2015-01-27 16:06 ` redi at gcc dot gnu.org
2015-01-27 16:09 ` alex-j-a at hotmail dot co.uk
2015-01-27 16:18 ` redi at gcc dot gnu.org
2015-01-27 16:29 ` redi at gcc dot gnu.org
2015-01-27 16:40 ` alex-j-a at hotmail dot co.uk [this message]
2015-01-27 16:51 ` alex-j-a at hotmail dot co.uk
2015-01-27 17:06 ` redi at gcc dot gnu.org
2015-01-28 13:40 ` redi at gcc dot gnu.org
2015-01-29 21:06 ` alex-j-a at hotmail dot co.uk
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