From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by sourceware.org (Postfix) with ESMTPS id 3BEFD385AC1F for ; Tue, 13 Sep 2022 10:57:20 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 3BEFD385AC1F Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=redhat.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1663066639; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=YlSHl1Z9N/y5sN4CbddFrXMS0IzCqU2qowzdJbUKVSM=; b=NtauStvfs9U8Ur3SBUMwqG1bci0rdqdj2BCeBLA6DUWslXpAZjPZtkK4GXrgIHm45w2djk D+XMLpXIyRSx3DHSLJ4vaLrxn82J2pMNNg6AfScLd98FlRPy788Jv8TQUlJu1T/7I/3ezc F6KPgnOa82X/xnBjcOzvLPnng1zHO+4= Received: from mail-qv1-f70.google.com (mail-qv1-f70.google.com [209.85.219.70]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_128_GCM_SHA256) id us-mta-669-PM6_W-ozNJaowD4i3jY3vQ-1; Tue, 13 Sep 2022 06:57:18 -0400 X-MC-Unique: PM6_W-ozNJaowD4i3jY3vQ-1 Received: by mail-qv1-f70.google.com with SMTP id lx4-20020a0562145f0400b00496ecf45ac4so7679414qvb.7 for ; Tue, 13 Sep 2022 03:57:17 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date; bh=YlSHl1Z9N/y5sN4CbddFrXMS0IzCqU2qowzdJbUKVSM=; b=FX7MoRh9oExaF8M+dhxJEAerVv5ifT6/h/AMBqFfj74L5/HBnz8kxSNxfd1pwvGGE1 Aynu8JUz0swWGt5s7M/uBCYRvt+FHR2VUXn9/9PBCOEZe2sJOLNdKuhhqn46vPbR0liv VUPRVuoULWSvhrTxWJPDyvwXByidPvYwbjSUlzqtRxZSgYIA9V0KBZRcsM9+V9mo1ke9 e0MSPent9GpHyD109TkJ/QVKndzOMwGIdYPf5FdBfzhoojuleXJJpIEk04Y8CG56/XwB 9UOZXja0ptTShcyiu57CUTs3A/e1E6/VmBL5fmM6seM0QlRs5Jmf/Vx+a7wG3Tc5ojZt LPSA== X-Gm-Message-State: ACgBeo1FgCIcxgiCREBjxUH9ypo1DVnIolVYhulh4qALNdIdCrjULK3B 6N9cHuLWBEx+n2vmcirp9Do8vg8T4B+MNM3zzH6b8pGZf35QxYbaKjtlW+5/Y6wkv9PzC+xO8TZ 3R+sMBcSQFYzMy6a1LJ586IqbISpdj1s= X-Received: by 2002:a05:622a:86:b0:342:f620:dc7a with SMTP id o6-20020a05622a008600b00342f620dc7amr27656409qtw.594.1663066637574; Tue, 13 Sep 2022 03:57:17 -0700 (PDT) X-Google-Smtp-Source: AA6agR4AC2sCAnXNUFp55Fy3zqq+t0hbEKBEH5wzbJ+pyXH3WRxJTJUaz3a7whtx0C2qSmHSjJuDUQukNtKAAnabNy8= X-Received: by 2002:a05:622a:86:b0:342:f620:dc7a with SMTP id o6-20020a05622a008600b00342f620dc7amr27656398qtw.594.1663066637354; Tue, 13 Sep 2022 03:57:17 -0700 (PDT) MIME-Version: 1.0 References: <20220912164531.1742034-1-ppalka@redhat.com> <20220912164531.1742034-2-ppalka@redhat.com> In-Reply-To: <20220912164531.1742034-2-ppalka@redhat.com> From: Jonathan Wakely Date: Tue, 13 Sep 2022 11:57:06 +0100 Message-ID: Subject: Re: [PATCH 2/4] libstdc++: Implement LWG 3569 changes to join_view::_Iterator To: Patrick Palka Cc: gcc-patches@gcc.gnu.org, libstdc++@gcc.gnu.org X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset="UTF-8" X-Spam-Status: No, score=-13.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,GIT_PATCH_0,RCVD_IN_DNSWL_LOW,SPF_HELO_NONE,SPF_NONE,TXREP,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: On Mon, 12 Sept 2022 at 17:46, Patrick Palka via Libstdc++ wrote: > > Tested on x86_64-pc-linux-gnu, does this look OK for trunk only? I briefly wondered whether we could just use a union there and provide the special members to init/copy/destroy it properly, but we already use in so it's probably not worth it. OK for trunk. > > libstdc++-v3/ChangeLog: > > * include/std/ranges (join_view::_Iterator::_M_satisfy): > Adjust resetting _M_inner as per LWG 3569. > (join_view::_Iterator::_M_inner): Wrap in std::optional > as per LWG 3569. > (join_view::_Iterator::_Iterator): Relax constraints as > per LWG 3569. > (join_view::_Iterator::operator*): Adjust as per LWG 3569. > (join_view::_Iterator::operator->): Likewise. > (join_view::_Iterator::operator++): Likewise. > (join_view::_Iterator::operator--): Likewise. > (join_view::_Iterator::iter_move): Likewise. > (join_view::_Iterator::iter_swap): Likewise. > * testsuite/std/ranges/adaptor/join.cc (test14): New test. > --- > libstdc++-v3/include/std/ranges | 28 +++++++++---------- > .../testsuite/std/ranges/adaptors/join.cc | 17 +++++++++++ > 2 files changed, 30 insertions(+), 15 deletions(-) > > diff --git a/libstdc++-v3/include/std/ranges b/libstdc++-v3/include/std/ranges > index 20eb4e82ac8..6297ce7cee3 100644 > --- a/libstdc++-v3/include/std/ranges > +++ b/libstdc++-v3/include/std/ranges > @@ -2746,7 +2746,7 @@ namespace views::__adaptor > } > > if constexpr (_S_ref_is_glvalue) > - _M_inner = _Inner_iter(); > + _M_inner.reset(); > } > > static constexpr auto > @@ -2769,7 +2769,7 @@ namespace views::__adaptor > using _Inner_iter = join_view::_Inner_iter<_Const>; > > _Outer_iter _M_outer = _Outer_iter(); > - _Inner_iter _M_inner = _Inner_iter(); > + optional<_Inner_iter> _M_inner; > _Parent* _M_parent = nullptr; > > public: > @@ -2780,9 +2780,7 @@ namespace views::__adaptor > = common_type_t, > range_difference_t>>; > > - _Iterator() requires (default_initializable<_Outer_iter> > - && default_initializable<_Inner_iter>) > - = default; > + _Iterator() requires default_initializable<_Outer_iter> = default; > > constexpr > _Iterator(_Parent* __parent, _Outer_iter __outer) > @@ -2801,7 +2799,7 @@ namespace views::__adaptor > > constexpr decltype(auto) > operator*() const > - { return *_M_inner; } > + { return **_M_inner; } > > // _GLIBCXX_RESOLVE_LIB_DEFECTS > // 3500. join_view::iterator::operator->() is bogus > @@ -2809,7 +2807,7 @@ namespace views::__adaptor > operator->() const > requires __detail::__has_arrow<_Inner_iter> > && copyable<_Inner_iter> > - { return _M_inner; } > + { return *_M_inner; } > > constexpr _Iterator& > operator++() > @@ -2820,7 +2818,7 @@ namespace views::__adaptor > else > return *_M_parent->_M_inner; > }(); > - if (++_M_inner == ranges::end(__inner_range)) > + if (++*_M_inner == ranges::end(__inner_range)) > { > ++_M_outer; > _M_satisfy(); > @@ -2850,9 +2848,9 @@ namespace views::__adaptor > { > if (_M_outer == ranges::end(_M_parent->_M_base)) > _M_inner = ranges::end(*--_M_outer); > - while (_M_inner == ranges::begin(*_M_outer)) > - _M_inner = ranges::end(*--_M_outer); > - --_M_inner; > + while (*_M_inner == ranges::begin(*_M_outer)) > + *_M_inner = ranges::end(*--_M_outer); > + --*_M_inner; > return *this; > } > > @@ -2879,14 +2877,14 @@ namespace views::__adaptor > > friend constexpr decltype(auto) > iter_move(const _Iterator& __i) > - noexcept(noexcept(ranges::iter_move(__i._M_inner))) > - { return ranges::iter_move(__i._M_inner); } > + noexcept(noexcept(ranges::iter_move(*__i._M_inner))) > + { return ranges::iter_move(*__i._M_inner); } > > friend constexpr void > iter_swap(const _Iterator& __x, const _Iterator& __y) > - noexcept(noexcept(ranges::iter_swap(__x._M_inner, __y._M_inner))) > + noexcept(noexcept(ranges::iter_swap(*__x._M_inner, *__y._M_inner))) > requires indirectly_swappable<_Inner_iter> > - { return ranges::iter_swap(__x._M_inner, __y._M_inner); } > + { return ranges::iter_swap(*__x._M_inner, *__y._M_inner); } > > friend _Iterator; > template friend struct _Sentinel; > diff --git a/libstdc++-v3/testsuite/std/ranges/adaptors/join.cc b/libstdc++-v3/testsuite/std/ranges/adaptors/join.cc > index 530ab6663b5..afc11d4bd7a 100644 > --- a/libstdc++-v3/testsuite/std/ranges/adaptors/join.cc > +++ b/libstdc++-v3/testsuite/std/ranges/adaptors/join.cc > @@ -21,6 +21,7 @@ > #include > #include > #include > +#include > #include > #include > #include > @@ -217,6 +218,21 @@ test13() > std::vector> v{{5, 6, 7}}; > v | l | std::views::join; > } > + > +void > +test14() > +{ > + // LWG 3569: join_view fails to support ranges of ranges with > + // non-default_initializable iterators > + auto ss = std::istringstream{"1 2 3"}; > + auto v = views::single(views::istream(ss)); > + using inner = ranges::range_reference_t; > + static_assert(ranges::input_range > + && !ranges::forward_range > + && !std::default_initializable>); > + VERIFY( ranges::equal(v | views::join, (int[]){1, 2, 3}) ); > +} > + > int > main() > { > @@ -233,4 +249,5 @@ main() > test11(); > test12(); > test13(); > + test14(); > } > -- > 2.37.3.542.gdd3f6c4cae >