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 [216.205.24.124]) by sourceware.org (Postfix) with ESMTP id D99FA39B3428 for ; Fri, 18 Jun 2021 21:57:26 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org D99FA39B3428 Received: from mail-wr1-f69.google.com (mail-wr1-f69.google.com [209.85.221.69]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-99-t8JMV89zN2yBQnD_kUTb3A-1; Fri, 18 Jun 2021 17:57:23 -0400 X-MC-Unique: t8JMV89zN2yBQnD_kUTb3A-1 Received: by mail-wr1-f69.google.com with SMTP id j2-20020a5d61820000b029011a6a8149b5so4568112wru.14 for ; Fri, 18 Jun 2021 14:57:23 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=6OPn0EBVREnaW/dyYrUZKHFOAbUio8wiUL6adiH+8fE=; b=YdndQcVitd3/VWnBxg1b2xVuTUmi6JKk6BN8z4gM0KcwLPRjHTG9vrbFQkU6ejsoQs +kE423TpO18ylkYfR/2/NXiwRgLm7WKpAN/qqWegg3FPQircRsgY2PD7ohewqPKPq7fw TrDYBIxkb6FuJxyRz5tpH44YIcMK6Qc6GvxID0SYuWJVtLlp/I/xnfaUQ5BcUEn5jgNa fDN5Cj+n+0ZI/o1zJLI234SghJmhF7U1qpgE09epKA7FrsajjJ5tiUAmEnRYJZUzKZ41 OdYNdg8AF4W4MolCL/thnEROufSdJ65afo5WLoKljuyLqk1nyIyTpWpqoG4u8NeIVPSL /yuA== X-Gm-Message-State: AOAM5321iUQAZHxecZ4Vxl6pftu91AcFoncgkJA4t7IFnK/jXKqMKq0k LGZqXwPDHT3r7TfVyUZW5/cNR1WzzpiTzTCWw0jL1sLK6TNvkjU2vwFtT3iQME7h8VGb196gt+s xXxDkxPgMv67X6pqkJ5VykwJa6wPx71c= X-Received: by 2002:a5d:5049:: with SMTP id h9mr14850436wrt.221.1624053442206; Fri, 18 Jun 2021 14:57:22 -0700 (PDT) X-Google-Smtp-Source: ABdhPJwROPxQbR96xY3v0/d7hKmzIUyp2Kew4a0X5UfMDf6sMS3srjYOFV6oyJVWlR+CFXlVirDl532v53FXqQo53lU= X-Received: by 2002:a5d:5049:: with SMTP id h9mr14850427wrt.221.1624053442001; Fri, 18 Jun 2021 14:57:22 -0700 (PDT) MIME-Version: 1.0 References: <20210617152206.1408001-1-ppalka@redhat.com> <20210617152206.1408001-4-ppalka@redhat.com> In-Reply-To: <20210617152206.1408001-4-ppalka@redhat.com> From: Jonathan Wakely Date: Fri, 18 Jun 2021 22:57:10 +0100 Message-ID: Subject: Re: [PATCH 4/5] libstdc++: Implement resolution of LWG 3478 as per P2210 To: Patrick Palka Cc: gcc Patches , "libstdc++" X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset="UTF-8" X-Spam-Status: No, score=-12.5 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, KAM_NUMSUBJECT, RCVD_IN_DNSWL_LOW, RCVD_IN_MSPIKE_H4, RCVD_IN_MSPIKE_WL, SPF_HELO_NONE, SPF_PASS, TXREP, URI_HEX autolearn=unavailable autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: libstdc++@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libstdc++ mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 18 Jun 2021 21:57:28 -0000 On Thu, 17 Jun 2021 at 16:51, Patrick Palka via Libstdc++ wrote: > > This implements the part of P2210R2 "Superior String Splitting" that > resolves LWG 3478 for split_view (now named lazy_split_view). > > libstdc++-v3/ChangeLog: > > * include/std/ranges (lazy_split_view::_OuterIter::__at_end): > Check _M_trailing_empty. > (lazy_split_view::_OuterIter::_M_trailing_empty): Define this > data member. > (lazy_split_view::_OuterIter::operator++): Set _M_trailing_empty > appropriately. > (lazy_split_view::_OuterIter::operator==): Compare > _M_trailing_empty. > * testsuite/std/ranges/adaptors/100479.cc (test03): Expect two > split parts instead of one. > * testsuite/std/ranges/adaptors/lazy_split.cc (test11): New test. OK (for trunk only, I think). > --- > libstdc++-v3/include/std/ranges | 21 +++++++++++++++---- > .../testsuite/std/ranges/adaptors/100479.cc | 6 +++--- > .../std/ranges/adaptors/lazy_split.cc | 15 +++++++++++++ > 3 files changed, 35 insertions(+), 7 deletions(-) > > diff --git a/libstdc++-v3/include/std/ranges b/libstdc++-v3/include/std/ranges > index cc1ef112ff1..78562924bee 100644 > --- a/libstdc++-v3/include/std/ranges > +++ b/libstdc++-v3/include/std/ranges > @@ -2879,7 +2879,7 @@ namespace views::__adaptor > > constexpr bool > __at_end() const > - { return __current() == ranges::end(_M_parent->_M_base); } > + { return __current() == ranges::end(_M_parent->_M_base) && !_M_trailing_empty; } > > // [range.lazy.split.outer] p1 > // Many of the following specifications refer to the notional member > @@ -2909,6 +2909,7 @@ namespace views::__adaptor > [[no_unique_address]] > __detail::__maybe_present_t, > iterator_t<_Base>> _M_current; > + bool _M_trailing_empty = false; > > public: > using iterator_concept = conditional_t, > @@ -2977,7 +2978,10 @@ namespace views::__adaptor > // 3505. lazy_split_view::outer-iterator::operator++ misspecified > const auto __end = ranges::end(_M_parent->_M_base); > if (__current() == __end) > - return *this; > + { > + _M_trailing_empty = false; > + return *this; > + } > const auto [__pbegin, __pend] = subrange{_M_parent->_M_pattern}; > if (__pbegin == __pend) > ++__current(); > @@ -2986,7 +2990,11 @@ namespace views::__adaptor > __current() = ranges::find(std::move(__current()), __end, > *__pbegin); > if (__current() != __end) > - ++__current(); > + { > + ++__current(); > + if (__current() == __end) > + _M_trailing_empty = true; > + } > } > else > do > @@ -2996,6 +3004,8 @@ namespace views::__adaptor > if (__p == __pend) > { > __current() = __b; > + if (__current() == __end) > + _M_trailing_empty = true; > break; > } > } while (++__current() != __end); > @@ -3018,7 +3028,10 @@ namespace views::__adaptor > friend constexpr bool > operator==(const _OuterIter& __x, const _OuterIter& __y) > requires forward_range<_Base> > - { return __x._M_current == __y._M_current; } > + { > + return __x._M_current == __y._M_current > + && __x._M_trailing_empty == __y._M_trailing_empty; > + } > > friend constexpr bool > operator==(const _OuterIter& __x, default_sentinel_t) > diff --git a/libstdc++-v3/testsuite/std/ranges/adaptors/100479.cc b/libstdc++-v3/testsuite/std/ranges/adaptors/100479.cc > index 9899ff92c0b..b8c1e6f4f57 100644 > --- a/libstdc++-v3/testsuite/std/ranges/adaptors/100479.cc > +++ b/libstdc++-v3/testsuite/std/ranges/adaptors/100479.cc > @@ -95,11 +95,11 @@ test03() > | views::drop_while([](auto) { return false; }) > | views::filter([](auto) { return true; }); > static_assert(ranges::forward_range); > - VERIFY( ranges::next(v.begin()) == v.end() ); > + VERIFY( ranges::distance(v) == 2 ); > auto w = v; > - VERIFY( ranges::next(w.begin()) == w.end() ); > + VERIFY( ranges::distance(v) == 2 ); > auto z = std::move(w); > - VERIFY( ranges::next(z.begin()) == z.end() ); > + VERIFY( ranges::distance(v) == 2 ); > return true; > } > > diff --git a/libstdc++-v3/testsuite/std/ranges/adaptors/lazy_split.cc b/libstdc++-v3/testsuite/std/ranges/adaptors/lazy_split.cc > index 12844525d86..133e9a7025b 100644 > --- a/libstdc++-v3/testsuite/std/ranges/adaptors/lazy_split.cc > +++ b/libstdc++-v3/testsuite/std/ranges/adaptors/lazy_split.cc > @@ -193,6 +193,20 @@ test10() > VERIFY( ranges::equal(v, (std::string_view[]){"x", "x"}) ); > } > > +void > +test11() > +{ > + // LWG 3478 > + static_assert(ranges::distance(views::lazy_split("text"sv, "text"sv)) == 2); > + static_assert(ranges::distance(views::lazy_split(" text "sv, ' ')) == 3); > + static_assert(ranges::distance(views::lazy_split(" t e x t "sv, ' ')) == 6); > + static_assert(ranges::distance(views::lazy_split(" text "sv, " "sv)) == 3); > + static_assert(ranges::distance(views::lazy_split(" text "sv, " "sv)) == 4); > + static_assert(ranges::distance(views::lazy_split(" text "sv, " "sv)) == 4); > + static_assert(ranges::distance(views::lazy_split("t"sv, 't')) == 2); > + static_assert(ranges::distance(views::lazy_split("text"sv, ""sv)) == 4); > +} > + > int > main() > { > @@ -206,4 +220,5 @@ main() > test08(); > test09(); > test10(); > + test11(); > } > -- > 2.32.0.93.g670b81a890 >