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author | Jonathan Wakely <jwakely@redhat.com> | 2020-11-25 17:18:44 +0000 |
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committer | Jonathan Wakely <jwakely@redhat.com> | 2020-11-25 17:22:47 +0000 |
commit | 9d908b7fc475b351622fa5630d4874068c789d70 (patch) | |
tree | 7c29046c94902dfca5068270f8b5b4aad49bbbc2 | |
parent | 1a8d1f54de371de88b2604d8c0e4e01306be8870 (diff) | |
download | gcc-9d908b7fc475b351622fa5630d4874068c789d70.zip gcc-9d908b7fc475b351622fa5630d4874068c789d70.tar.gz gcc-9d908b7fc475b351622fa5630d4874068c789d70.tar.bz2 |
libstdc++: Fix missing subsumption in std::iterator_traits [PR 97935]
libstdc++-v3/ChangeLog:
PR libstdc++/97935
* include/bits/iterator_concepts.h (__detail::__iter_without_category):
New helper concept.
(__iterator_traits::__cat): Use __detail::__iter_without_category.
* testsuite/24_iterators/associated_types/iterator.traits.cc: New test.
-rw-r--r-- | libstdc++-v3/include/bits/iterator_concepts.h | 17 | ||||
-rw-r--r-- | libstdc++-v3/testsuite/24_iterators/associated_types/iterator.traits.cc | 56 |
2 files changed, 67 insertions, 6 deletions
diff --git a/libstdc++-v3/include/bits/iterator_concepts.h b/libstdc++-v3/include/bits/iterator_concepts.h index 8ff4f86..6668caa 100644 --- a/libstdc++-v3/include/bits/iterator_concepts.h +++ b/libstdc++-v3/include/bits/iterator_concepts.h @@ -357,6 +357,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION template<typename _Iter> concept __iter_without_nested_types = !__iter_with_nested_types<_Iter>; + + template<typename _Iter> + concept __iter_without_category + = !requires { typename _Iter::iterator_category; }; + } // namespace __detail template<typename _Iterator> @@ -396,20 +401,20 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION { using type = typename _Iter::iterator_category; }; template<typename _Iter> - requires (!requires { typename _Iter::iterator_category; } - && __detail::__cpp17_randacc_iterator<_Iter>) + requires __detail::__iter_without_category<_Iter> + && __detail::__cpp17_randacc_iterator<_Iter> struct __cat<_Iter> { using type = random_access_iterator_tag; }; template<typename _Iter> - requires (!requires { typename _Iter::iterator_category; } - && __detail::__cpp17_bidi_iterator<_Iter>) + requires __detail::__iter_without_category<_Iter> + && __detail::__cpp17_bidi_iterator<_Iter> struct __cat<_Iter> { using type = bidirectional_iterator_tag; }; template<typename _Iter> - requires (!requires { typename _Iter::iterator_category; } - && __detail::__cpp17_fwd_iterator<_Iter>) + requires __detail::__iter_without_category<_Iter> + && __detail::__cpp17_fwd_iterator<_Iter> struct __cat<_Iter> { using type = forward_iterator_tag; }; diff --git a/libstdc++-v3/testsuite/24_iterators/associated_types/iterator.traits.cc b/libstdc++-v3/testsuite/24_iterators/associated_types/iterator.traits.cc new file mode 100644 index 0000000..c3549fe --- /dev/null +++ b/libstdc++-v3/testsuite/24_iterators/associated_types/iterator.traits.cc @@ -0,0 +1,56 @@ +// Copyright (C) 2020 Free Software Foundation, Inc. +// +// This file is part of the GNU ISO C++ Library. This library is free +// software; you can redistribute it and/or modify it under the +// terms of the GNU General Public License as published by the +// Free Software Foundation; either version 3, or (at your option) +// any later version. + +// This library is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU General Public License for more details. + +// You should have received a copy of the GNU General Public License along +// with this library; see the file COPYING3. If not see +// <http://www.gnu.org/licenses/>. + +// { dg-options "-std=gnu++2a" } +// { dg-do compile { target c++2a } } + +#include <iterator> + +struct bidi_iterator +{ + // No nested reference and pointer types. + // No iterator_category. + + // cpp17-iterator requirements: + int& operator*() const; + bidi_iterator& operator++(); + bidi_iterator operator++(int); + + // cpp17-input-iterator requirements: + friend bool operator==(const bidi_iterator&, const bidi_iterator&); + using difference_type = long long; + using value_type = int; + + // cpp17-forward-iterator requirements: + bidi_iterator(); + + // cpp17-bidirectional-iterator requirements: + bidi_iterator& operator--(); + bidi_iterator operator--(int); +}; + +void +test01() +{ + // PR libstdc++/97935 + // Missing subsumption in iterator category detection + using namespace std; + static_assert(__detail::__cpp17_bidi_iterator<bidi_iterator>); + static_assert(same_as<iterator_traits<bidi_iterator>::iterator_category, + bidirectional_iterator_tag>, + "PR libstdc++/97935"); +} |