From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <libstdc++-return-14977-listarch-libstdc++=gcc.gnu.org@gcc.gnu.org>
Received: (qmail 102175 invoked by alias); 24 Feb 2020 14:16:36 -0000
Mailing-List: contact libstdc++-help@gcc.gnu.org; run by ezmlm
Precedence: bulk
List-Id: <libstdc++.gcc.gnu.org>
List-Subscribe: <mailto:libstdc++-subscribe@gcc.gnu.org>
List-Archive: <http://gcc.gnu.org/ml/libstdc++/>
List-Post: <mailto:libstdc++@gcc.gnu.org>
List-Help: <mailto:libstdc++-help@gcc.gnu.org>, <http://gcc.gnu.org/ml/#faqs>
Sender: libstdc++-owner@gcc.gnu.org
Received: (qmail 102159 invoked by uid 89); 24 Feb 2020 14:16:35 -0000
Authentication-Results: sourceware.org; auth=none
X-Spam-SWARE-Status: No, score=-1.9 required=5.0 tests=AWL,BAYES_00,FREEMAIL_FROM,RCVD_IN_DNSWL_NONE,SPF_PASS autolearn=ham version=3.3.1 spammy=daniel, Daniel, (unknown), H*r:ip*209.85.208.195
X-HELO: mail-lj1-f195.google.com
Received: from mail-lj1-f195.google.com (HELO mail-lj1-f195.google.com) (209.85.208.195) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Mon, 24 Feb 2020 14:16:34 +0000
Received: by mail-lj1-f195.google.com with SMTP id o15so10281436ljg.6;        Mon, 24 Feb 2020 06:16:34 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;        d=gmail.com; s=20161025;        h=mime-version:references:in-reply-to:from:date:message-id:subject:to         :cc;        bh=j2C0WWnBtocAHANN+yPTr2Z0I4v9Te57aUnWzdl6hdY=;        b=Xjs9s22H93v8ZCAT5dbTl8v9oeing194kPuAqZjhpcn+95sCSTIo0mThpnZkjx5mZe         bonQmzfIbg6mvDo7hS+aX6LGv6a10xb3ZTy1c5wM9a55ZszguN9x7oighj+2uOvxYglY         YoX+OTNVv4cTOOEHm3sglvfCiG8HXyfmLR1D/e7hpLWnxAq5bxEZFiaCEHuIrdbO/xjX         LOHDG2jdSvq0Nq9Kckv7JrZVypRA8uqjustJsTAI1Z61ye11BzqjzST0wowRBB3TNQma         n+9yeqTuNp7us0EITk66lpUWdbEQDCYk9Si+xLMEzqO3zrZ5QHy1BAVWZd87JBlJ+vmZ         vXsA==
MIME-Version: 1.0
References: <20200221192922.2412286-1-ppalka@redhat.com> <alpine.DEB.2.22.395.2002211553330.1723@idea> <20200224134742.GC9441@redhat.com> <alpine.DEB.2.22.395.2002240853580.1709@idea>
In-Reply-To: <alpine.DEB.2.22.395.2002240853580.1709@idea>
From: =?UTF-8?Q?Daniel_Kr=C3=BCgler?= <daniel.kruegler@gmail.com>
Date: Mon, 24 Feb 2020 14:16:00 -0000
Message-ID: <CAGNvRgDtGWpMf7siZBrnbf4SB_b1NBfOaAQky0a3=Sxt3n-fgg@mail.gmail.com>
Subject: Re: [PATCH] libstdc++: P0769R2 Add shift to <algorithm>
To: Patrick Palka <ppalka@redhat.com>
Cc: Jonathan Wakely <jwakely@redhat.com>, gcc-patches List <gcc-patches@gcc.gnu.org>, 	"libstdc++" <libstdc++@gcc.gnu.org>
Content-Type: text/plain; charset="UTF-8"
X-SW-Source: 2020-02/txt/msg00157.txt.bz2

Am Mo., 24. Feb. 2020 um 15:12 Uhr schrieb Patrick Palka <ppalka@redhat.com>:
>
> On Mon, 24 Feb 2020, Jonathan Wakely wrote:
>
[...]
> > > @@ -3683,6 +3683,98 @@ namespace ranges
> > >   inline constexpr __prev_permutation_fn prev_permutation{};
> > >
> > > } // namespace ranges
> > > +
> > > +  template<class ForwardIterator>
> > > +    constexpr ForwardIterator
> > > +    shift_left(ForwardIterator __first, ForwardIterator __last,
> > > +          typename iterator_traits<ForwardIterator>::difference_type __n)
> > > +    {
> > > +      __glibcxx_assert(__n >= 0);
> >
> > If I'm reading the current draft correctly, n < 0 is allowed (and does
> > nothing) so we shouldn't assert here.
>
> From what I can tell, this is changed by P1243R4 (Rangify new
> algorithms) which adds the precondition n >= 0 to these routines.

Yes, that's correct. This part of the wording applied the accepted
changes of p1233r1.

- Daniel