{"id":2219834,"url":"http://patchwork.ozlabs.org/api/patches/2219834/?format=json","web_url":"http://patchwork.ozlabs.org/project/gcc/patch/20260404170122.2928689-2-ivan.lazaric1@gmail.com/","project":{"id":17,"url":"http://patchwork.ozlabs.org/api/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,"list_archive_url":"","list_archive_url_format":"","commit_url_format":""},"msgid":"<20260404170122.2928689-2-ivan.lazaric1@gmail.com>","list_archive_url":null,"date":"2026-04-04T17:01:23","name":"libstdc++: Implement P1789R3: structured bindings for std::integer_sequence","commit_ref":null,"pull_url":null,"state":"new","archived":false,"hash":"e7e6ee832adeca5507c5748fa18f5373c9012e33","submitter":{"id":92628,"url":"http://patchwork.ozlabs.org/api/people/92628/?format=json","name":"Ivan Lazaric","email":"ivan.lazaric1@gmail.com"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/gcc/patch/20260404170122.2928689-2-ivan.lazaric1@gmail.com/mbox/","series":[{"id":498741,"url":"http://patchwork.ozlabs.org/api/series/498741/?format=json","web_url":"http://patchwork.ozlabs.org/project/gcc/list/?series=498741","date":"2026-04-04T17:01:23","name":"libstdc++: Implement P1789R3: structured bindings for std::integer_sequence","version":1,"mbox":"http://patchwork.ozlabs.org/series/498741/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/2219834/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/2219834/checks/","tags":{},"related":[],"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 (2048-bit key;\n unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256\n header.s=20251104 header.b=KNRFuoiI;\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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}\n };\n \n+#if __glibcxx_integer_sequence >= 202511L // C++ >= 26\n+ template\n+ struct tuple_size>\n+ : integral_constant { };\n+\n+ template\n+ struct tuple_element<__i, integer_sequence<_Tp, _Idx...>>\n+ {\n+\tstatic_assert(__i < sizeof...(_Idx));\n+\tusing type = _Tp;\n+ };\n+\n+ template\n+ struct tuple_element<__i, const integer_sequence<_Tp, _Idx...>>\n+ {\n+\tstatic_assert(__i < sizeof...(_Idx));\n+\tusing type = _Tp;\n+ };\n+\n+ template\n+ constexpr _Tp\n+ get (integer_sequence<_Tp, _Idx...>) noexcept\n+ {\n+\tstatic_assert(__i < sizeof...(_Idx));\n+\treturn _Idx...[__i];\n+ }\n+#endif // __glibcxx_integer_sequence >= 202511L\n+\n /// Alias template make_integer_sequence\n template\n using make_integer_sequence\ndiff --git a/libstdc++-v3/include/bits/version.def b/libstdc++-v3/include/bits/version.def\nindex b89e60d156d..6103f6a41d1 100644\n--- a/libstdc++-v3/include/bits/version.def\n+++ b/libstdc++-v3/include/bits/version.def\n@@ -184,6 +184,11 @@ ftms = {\n \n ftms = {\n name = integer_sequence;\n+ values = {\n+ v = 202511;\n+ cxxmin = 26;\n+ extra_cond = \"__cpp_pack_indexing\";\n+ };\n values = {\n v = 201304;\n cxxmin = 14;\ndiff --git a/libstdc++-v3/include/bits/version.h b/libstdc++-v3/include/bits/version.h\nindex d73b547e1b0..0de2ad9e5f3 100644\n--- a/libstdc++-v3/include/bits/version.h\n+++ b/libstdc++-v3/include/bits/version.h\n@@ -186,7 +186,12 @@\n #undef __glibcxx_want_exchange_function\n \n #if !defined(__cpp_lib_integer_sequence)\n-# if (__cplusplus >= 201402L)\n+# if (__cplusplus > 202302L) && (__cpp_pack_indexing)\n+# define __glibcxx_integer_sequence 202511L\n+# if defined(__glibcxx_want_all) || defined(__glibcxx_want_integer_sequence)\n+# define __cpp_lib_integer_sequence 202511L\n+# endif\n+# elif (__cplusplus >= 201402L)\n # define __glibcxx_integer_sequence 201304L\n # if defined(__glibcxx_want_all) || defined(__glibcxx_want_integer_sequence)\n # define __cpp_lib_integer_sequence 201304L\ndiff --git a/libstdc++-v3/testsuite/20_util/integer_sequence/structured_binding.cc b/libstdc++-v3/testsuite/20_util/integer_sequence/structured_binding.cc\nnew file mode 100644\nindex 00000000000..b8e9fa1caa1\n--- /dev/null\n+++ b/libstdc++-v3/testsuite/20_util/integer_sequence/structured_binding.cc\n@@ -0,0 +1,29 @@\n+// { dg-do compile { target c++26 } }\n+\n+#include \n+\n+#if __cpp_lib_integer_sequence < 202511L\n+# error \"Feature-test macro __cpp_lib_integer_sequence is incorrect\"\n+#endif\n+\n+constexpr auto\n+destructure_sum(auto seq)\n+{\n+ auto [...elems] = seq;\n+ return (0 + ... + elems);\n+}\n+\n+using IS1 = std::make_index_sequence<10>;\n+static_assert(std::tuple_size_v == 10);\n+static_assert(std::is_same_v, size_t>);\n+static_assert(std::get<7>(IS1{}) == 7);\n+static_assert(destructure_sum(IS1{}) == 45);\n+\n+using IS2 = std::integer_sequence;\n+static_assert(std::tuple_size_v == 3);\n+static_assert(std::is_same_v, int>);\n+static_assert(std::get<2>(IS2{}) == -13);\n+static_assert(destructure_sum(IS2{}) == 130);\n+\n+using IS3 = std::integer_sequence;\n+static_assert(std::tuple_size_v == 0);\n","prefixes":[]}