public inbox for gcc-prs@sourceware.org
help / color / mirror / Atom feed
From: Joe Buck <jbuck@synopsys.com>
To: paolo@gcc.gnu.org
Cc: gcc-prs@gcc.gnu.org,
Subject: Re: libstdc++/8780: std::vector iterators not recognized as pointers by templates in certain cases
Date: Wed, 04 Dec 2002 10:26:00 -0000	[thread overview]
Message-ID: <20021204182601.17574.qmail@sources.redhat.com> (raw)

The following reply was made to PR libstdc++/8780; it has been noted by GNATS.

From: Joe Buck <jbuck@synopsys.com>
To: gcc-gnats@gcc.gnu.org, gcc-prs@gcc.gnu.org, johnb@stl.sarov.ru,
   gcc-bugs@gcc.gnu.org, paolo@gcc.gnu.org
Cc:  
Subject: Re: libstdc++/8780: std::vector iterators not recognized as pointers
 by templates in certain cases
Date: Wed, 04 Dec 2002 10:21:03 -0800

 http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=8780
 
 Thanks for the report, but this is not a bug.
 
 Any code that assumes that a vector<T>::iterator is a pointer is 
 non-portable
 and will break on many C++ implementations (including debug implementations,
 which use extra fields in the iterator to detect dereferencing of out of 
 range
 iterators).
 
 
 If you have code that makes such assumptions, then for cases where you know
 that the iterator is not pointing to vec.end(), the construct &*iter 
 will give
 a valid pointer to the data (and you may portably assume that the data are
 stored contiguously in the vector).  A portable one-past-the-end pointer is
 1+&vec.back() .
 
 


             reply	other threads:[~2002-12-04 18:26 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2002-12-04 10:26 Joe Buck [this message]
  -- strict thread matches above, loose matches on Subject: below --
2002-12-04 10:24 paolo
2002-12-02  5:31 paolo
2002-12-02  1:06 johnb

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20021204182601.17574.qmail@sources.redhat.com \
    --to=jbuck@synopsys.com \
    --cc=gcc-prs@gcc.gnu.org \
    --cc=paolo@gcc.gnu.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).