diff --git a/libstdc++-v3/include/bits/iterator_concepts.h b/libstdc++-v3/include/bits/iterator_concepts.h index 490a362cdf1cabc8b360d429a0ba1f9b48f88dae..669d3ddfd1ec13e35582c21086ca811e5feca68a 100644 --- a/libstdc++-v3/include/bits/iterator_concepts.h +++ b/libstdc++-v3/include/bits/iterator_concepts.h @@ -333,10 +333,12 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION typename incrementable_traits<_Iter>::difference_type>; }; + // _GLIBCXX_RESOLVE_LIB_DEFECTS + // 3798. Rvalue reference and iterator_category template<typename _Iter> concept __cpp17_fwd_iterator = __cpp17_input_iterator<_Iter> && constructible_from<_Iter> - && is_lvalue_reference_v<iter_reference_t<_Iter>> + && is_reference_v<iter_reference_t<_Iter>> && same_as<remove_cvref_t<iter_reference_t<_Iter>>, typename indirectly_readable_traits<_Iter>::value_type> && requires(_Iter __it) diff --git a/libstdc++-v3/include/std/ranges b/libstdc++-v3/include/std/ranges index 98442dcfbd5177397544306ae7789284ac387636..5b4558885363511bcbc6a3ad508f259266fdd4a9 100644 --- a/libstdc++-v3/include/std/ranges +++ b/libstdc++-v3/include/std/ranges @@ -1892,7 +1892,9 @@ namespace views::__adaptor using _Base = transform_view::_Base<_Const>; using _Res = invoke_result_t<__maybe_const_t<_Const, _Fp>&, range_reference_t<_Base>>; - if constexpr (is_lvalue_reference_v<_Res>) + // _GLIBCXX_RESOLVE_LIB_DEFECTS + // 3798. Rvalue reference and iterator_category + if constexpr (is_reference_v<_Res>) { using _Cat = typename iterator_traits<iterator_t<_Base>>::iterator_category; @@ -5047,7 +5049,9 @@ namespace views::__adaptor using __detail::__range_iter_cat; using _Res = invoke_result_t<__maybe_const_t<_Const, _Fp>&, range_reference_t<__maybe_const_t<_Const, _Vs>>...>; - if constexpr (!is_lvalue_reference_v<_Res>) + // _GLIBCXX_RESOLVE_LIB_DEFECTS + // 3798. Rvalue reference and iterator_category + if constexpr (!is_reference_v<_Res>) return input_iterator_tag{}; else if constexpr ((derived_from<__range_iter_cat<_Vs, _Const>, random_access_iterator_tag> && ...)) @@ -5820,7 +5824,9 @@ namespace views::__adaptor using _Res = invoke_result_t<__unarize<__maybe_const_t<_Const, _Fp>&, _Nm>, range_reference_t<_Base>>; using _Cat = typename iterator_traits<iterator_t<_Base>>::iterator_category; - if constexpr (!is_lvalue_reference_v<_Res>) + // _GLIBCXX_RESOLVE_LIB_DEFECTS + // 3798. Rvalue reference and iterator_category + if constexpr (!is_reference_v<_Res>) return input_iterator_tag{}; else if constexpr (derived_from<_Cat, random_access_iterator_tag>) return random_access_iterator_tag{}; @@ -7228,8 +7234,10 @@ namespace views::__adaptor using _OuterCat = typename iterator_traits<_OuterIter>::iterator_category; using _InnerCat = typename iterator_traits<_InnerIter>::iterator_category; using _PatternCat = typename iterator_traits<_PatternIter>::iterator_category; - if constexpr (!is_lvalue_reference_v<common_reference_t<iter_reference_t<_InnerIter>, - iter_reference_t<_PatternIter>>>) + // _GLIBCXX_RESOLVE_LIB_DEFECTS + // 3798. Rvalue reference and iterator_category + if constexpr (!is_reference_v<common_reference_t<iter_reference_t<_InnerIter>, + iter_reference_t<_PatternIter>>>) return input_iterator_tag{}; else if constexpr (derived_from<_OuterCat, bidirectional_iterator_tag> && derived_from<_InnerCat, bidirectional_iterator_tag> diff --git a/libstdc++-v3/testsuite/std/ranges/adaptors/transform.cc b/libstdc++-v3/testsuite/std/ranges/adaptors/transform.cc index ca695349650a5e0d0aaeff47e2355785d104d5cc..e1b74353e6327dec87ef0dd83868e880d7de792d 100644 --- a/libstdc++-v3/testsuite/std/ranges/adaptors/transform.cc +++ b/libstdc++-v3/testsuite/std/ranges/adaptors/transform.cc @@ -214,6 +214,21 @@ test10() static_assert(std::same_as<cat, std::random_access_iterator_tag>); } +void +test11() +{ + struct MoveIt { + int&& operator()(int& i) const { return std::move(i); } + }; + + int x[] {2, 4}; + auto xform = x | views::transform(MoveIt{}); + using iterator = decltype(xform.begin()); + // LWG 3798. Rvalue reference and iterator_category + using cat = std::iterator_traits<iterator>::iterator_category; + static_assert(std::same_as<cat, std::random_access_iterator_tag>); +} + int main() { @@ -227,4 +242,5 @@ main() test08(); test09(); test10(); + test11(); }