From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 1888) id 5C3E43858C5E; Thu, 9 Mar 2023 18:41:39 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 5C3E43858C5E DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1678387299; bh=/GYFvvCDRtYFi0bXA9wBPOxiOIGK4IuAtj9OIN8OK7o=; h=From:To:Subject:Date:From; b=skOx1WriEXBQ17i7C6TUorFSrWkmfGgIIBQ5ttdk27HWApwgDshmi3+ycs7mfZb5t M93Hi3t7r6BB9+U9dgO6iasB7miYh6foOPj2+vhMmW9vq5vAbvv4p3/83EbCBYQPoH 59GhsqKZRZ1QZKR55Bj3tmoeRm2qlLlsLdi7Aj2A= MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="utf-8" From: Patrick Palka To: gcc-cvs@gcc.gnu.org, libstdc++-cvs@gcc.gnu.org Subject: [gcc r13-6562] libstdc++: Implement LWG 3820/3849 changes to cartesian_product_view X-Act-Checkin: gcc X-Git-Author: Patrick Palka X-Git-Refname: refs/heads/master X-Git-Oldrev: 065c93b89c5e97dcbfd79ee5172cf6800c286896 X-Git-Newrev: 96abc8222464fb1c4fba9f2ffe3fd1b081a9196e Message-Id: <20230309184139.5C3E43858C5E@sourceware.org> Date: Thu, 9 Mar 2023 18:41:39 +0000 (GMT) List-Id: https://gcc.gnu.org/g:96abc8222464fb1c4fba9f2ffe3fd1b081a9196e commit r13-6562-g96abc8222464fb1c4fba9f2ffe3fd1b081a9196e Author: Patrick Palka Date: Thu Mar 9 13:41:03 2023 -0500 libstdc++: Implement LWG 3820/3849 changes to cartesian_product_view The LWG 3820 testcase revealed a bug in _M_advance, which this patch also fixes. libstdc++-v3/ChangeLog: * include/std/ranges (cartesian_product_view::_Iterator::_Iterator): Remove constraint on default constructor as per LWG 3849. (cartesian_product_view::_Iterator::_M_prev): Adjust position of _Nm > 0 test as per LWG 3820. (cartesian_product_view::_Iterator::_M_advance): Perform bounds checking only on sized cartesian products. * testsuite/std/ranges/cartesian_product/1.cc (test08): New test. Diff: --- libstdc++-v3/include/std/ranges | 23 ++++++++++++---------- .../testsuite/std/ranges/cartesian_product/1.cc | 9 +++++++++ 2 files changed, 22 insertions(+), 10 deletions(-) diff --git a/libstdc++-v3/include/std/ranges b/libstdc++-v3/include/std/ranges index f6809413ee1..0725e700c47 100644 --- a/libstdc++-v3/include/std/ranges +++ b/libstdc++-v3/include/std/ranges @@ -8224,7 +8224,7 @@ namespace views::__adaptor range_reference_t<__maybe_const_t<_Const, _Vs>>...>; using difference_type = decltype(cartesian_product_view::_S_difference_type()); - _Iterator() requires forward_range<__maybe_const_t<_Const, _First>> = default; + _Iterator() = default; constexpr _Iterator(_Iterator __i) @@ -8389,12 +8389,12 @@ namespace views::__adaptor _M_prev() { auto& __it = std::get<_Nm>(_M_current); - if (__it == ranges::begin(std::get<_Nm>(_M_parent->_M_bases))) - { - __it = __detail::__cartesian_common_arg_end(std::get<_Nm>(_M_parent->_M_bases)); - if constexpr (_Nm > 0) + if constexpr (_Nm > 0) + if (__it == ranges::begin(std::get<_Nm>(_M_parent->_M_bases))) + { + __it = __detail::__cartesian_common_arg_end(std::get<_Nm>(_M_parent->_M_bases)); _M_prev<_Nm - 1>(); - } + } --__it; } @@ -8415,10 +8415,13 @@ namespace views::__adaptor if constexpr (_Nm == 0) { #ifdef _GLIBCXX_ASSERTIONS - auto __size = ranges::ssize(__r); - auto __begin = ranges::begin(__r); - auto __offset = __it - __begin; - __glibcxx_assert(__offset + __x >= 0 && __offset + __x <= __size); + if constexpr (sized_range<__maybe_const_t<_Const, _First>>) + { + auto __size = ranges::ssize(__r); + auto __begin = ranges::begin(__r); + auto __offset = __it - __begin; + __glibcxx_assert(__offset + __x >= 0 && __offset + __x <= __size); + } #endif __it += __x; } diff --git a/libstdc++-v3/testsuite/std/ranges/cartesian_product/1.cc b/libstdc++-v3/testsuite/std/ranges/cartesian_product/1.cc index f52c2b96d58..ef2ece4a168 100644 --- a/libstdc++-v3/testsuite/std/ranges/cartesian_product/1.cc +++ b/libstdc++-v3/testsuite/std/ranges/cartesian_product/1.cc @@ -201,6 +201,14 @@ test07() VERIFY( i == 5 ); } +void +test08() +{ + // LWG 3820 + auto r = views::cartesian_product(views::iota(0)); + r.begin() += 3; +} + int main() { @@ -211,4 +219,5 @@ main() test05(); static_assert(test06()); test07(); + test08(); }