{"id":2220927,"url":"http://patchwork.ozlabs.org/api/1.1/patches/2220927/?format=json","web_url":"http://patchwork.ozlabs.org/project/gcc/patch/20260408121941.4047772-1-ppalka@redhat.com/","project":{"id":17,"url":"http://patchwork.ozlabs.org/api/1.1/projects/17/?format=json","name":"GNU Compiler Collection","link_name":"gcc","list_id":"gcc-patches.gcc.gnu.org","list_email":"gcc-patches@gcc.gnu.org","web_url":null,"scm_url":null,"webscm_url":null},"msgid":"<20260408121941.4047772-1-ppalka@redhat.com>","date":"2026-04-08T12:19:41","name":"libstdc++/ranges: Implement LWG 3599 change to lazy_split_view","commit_ref":null,"pull_url":null,"state":"new","archived":false,"hash":"12f6553e3768a279502af0af699ac6f1c651fe42","submitter":{"id":78319,"url":"http://patchwork.ozlabs.org/api/1.1/people/78319/?format=json","name":"Patrick Palka","email":"ppalka@redhat.com"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/gcc/patch/20260408121941.4047772-1-ppalka@redhat.com/mbox/","series":[{"id":499132,"url":"http://patchwork.ozlabs.org/api/1.1/series/499132/?format=json","web_url":"http://patchwork.ozlabs.org/project/gcc/list/?series=499132","date":"2026-04-08T12:19:41","name":"libstdc++/ranges: Implement LWG 3599 change to lazy_split_view","version":1,"mbox":"http://patchwork.ozlabs.org/series/499132/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/2220927/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/2220927/checks/","tags":{},"headers":{"Return-Path":"","X-Original-To":["incoming@patchwork.ozlabs.org","gcc-patches@gcc.gnu.org"],"Delivered-To":["patchwork-incoming@legolas.ozlabs.org","gcc-patches@gcc.gnu.org"],"Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (1024-bit key;\n unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256\n header.s=mimecast20190719 header.b=iasugizT;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=gcc.gnu.org\n (client-ip=2620:52:6:3111::32; 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charset=\"US-ASCII\"; x-default=true","X-BeenThere":"gcc-patches@gcc.gnu.org","X-Mailman-Version":"2.1.30","Precedence":"list","List-Id":"Gcc-patches mailing list ","List-Unsubscribe":",\n ","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n ","Errors-To":"gcc-patches-bounces~incoming=patchwork.ozlabs.org@gcc.gnu.org"},"content":"Tested on x86_64-pc-linux-gnu, does this look OK for trunk/backports?\n\n-- >8 --\n\nlibstdc++-v3/ChangeLog:\n\n\t* include/std/ranges (lazy_split_view::begin): Add\n\tconst _Pattern contraint on const overload as per LWG 3599.\n\t(lazy_split_view::end): Likewise.\n\t* testsuite/std/ranges/adaptors/lazy_split.cc (test14): New\n\ttest.\n---\n libstdc++-v3/include/std/ranges | 4 +++-\n .../testsuite/std/ranges/adaptors/lazy_split.cc | 10 ++++++++++\n 2 files changed, 13 insertions(+), 1 deletion(-)","diff":"diff --git a/libstdc++-v3/include/std/ranges b/libstdc++-v3/include/std/ranges\nindex 0aa4191e04f6..41175fd45e4b 100644\n--- a/libstdc++-v3/include/std/ranges\n+++ b/libstdc++-v3/include/std/ranges\n@@ -3809,6 +3809,7 @@ namespace views::__adaptor\n \n constexpr auto\n begin() const requires forward_range<_Vp> && forward_range\n+\t&& forward_range\n {\n \treturn _OuterIter{this, ranges::begin(_M_base)};\n }\n@@ -3826,7 +3827,8 @@ namespace views::__adaptor\n {\n \tif constexpr (forward_range<_Vp>\n \t\t && forward_range\n-\t\t && common_range)\n+\t\t && common_range\n+\t\t && forward_range)\n \t return _OuterIter{this, ranges::end(_M_base)};\n \telse\n \t return default_sentinel;\ndiff --git a/libstdc++-v3/testsuite/std/ranges/adaptors/lazy_split.cc b/libstdc++-v3/testsuite/std/ranges/adaptors/lazy_split.cc\nindex 60ee7d70580e..1c69b8f27cfd 100644\n--- a/libstdc++-v3/testsuite/std/ranges/adaptors/lazy_split.cc\n+++ b/libstdc++-v3/testsuite/std/ranges/adaptors/lazy_split.cc\n@@ -239,6 +239,15 @@ test13()\n constexpr decltype(views::lazy_split(views::single(0), 0).begin()) it;\n }\n \n+void\n+test14()\n+{\n+ // LWG 3599\n+ auto p = views::iota(0) | views::take(1) | views::reverse;\n+ auto r = views::single(42) | views::lazy_split(p);\n+ auto f = r.front();\n+}\n+\n int\n main()\n {\n@@ -255,4 +264,5 @@ main()\n test11();\n static_assert(test12());\n test13();\n+ test14();\n }\n","prefixes":[]}