On Tue, 18 May 2021, Patrick Palka wrote: > This implements the P0896 changes to reverse_view's member types
Whoops, s/reverse_view/reverse_iterator rather... consider this typo fixed throughout. > value_type, difference_type and reference in C++20 mode, which fixes > problems taking the reverse_iterator of an iterator with a non-integral > difference_type (such as iota_view<long long>). > > Tested on x86_64-pc-linux-gnu, does this look OK for trunk and perhaps > 10/11? > > libstdc++-v3/ChangeLog: > > PR libstdc++/100639 > * include/bits/stl_iterator.h (reverse_view::difference_type): > In C++20 mode, define in terms of iter_difference_t as per P0896. > (reverse_view::reference): Likewise, but with iter_reference_t. > (reverse_view::value_type): Likewise, but with iter_value_t. > * testsuite/std/ranges/adaptors/reverse.cc (test08): New test. > * testsuite/24_iterators/reverse_iterator/100639.cc: New test. > --- > libstdc++-v3/include/bits/stl_iterator.h | 9 +++-- > .../24_iterators/reverse_iterator/100639.cc | 37 +++++++++++++++++++ > .../testsuite/std/ranges/adaptors/reverse.cc | 12 ++++++ > 3 files changed, 55 insertions(+), 3 deletions(-) > create mode 100644 > libstdc++-v3/testsuite/24_iterators/reverse_iterator/100639.cc > > diff --git a/libstdc++-v3/include/bits/stl_iterator.h > b/libstdc++-v3/include/bits/stl_iterator.h > index 2409cd71f86..8768624b7d1 100644 > --- a/libstdc++-v3/include/bits/stl_iterator.h > +++ b/libstdc++-v3/include/bits/stl_iterator.h > @@ -149,11 +149,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION > > public: > typedef _Iterator iterator_type; > - typedef typename __traits_type::difference_type difference_type; > typedef typename __traits_type::pointer pointer; > +#if __cplusplus <= 201703L > + typedef typename __traits_type::difference_type difference_type; > typedef typename __traits_type::reference reference; > - > -#if __cplusplus > 201703L && __cpp_lib_concepts > +#else > using iterator_concept > = conditional_t<random_access_iterator<_Iterator>, > random_access_iterator_tag, > @@ -161,6 +161,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION > using iterator_category > = __detail::__clamp_iter_cat<typename __traits_type::iterator_category, > random_access_iterator_tag>; > + using value_type = iter_value_t<_Iterator>; > + using difference_type = iter_difference_t<_Iterator>; > + using reference = iter_reference_t<_Iterator>; > #endif > > /** > diff --git a/libstdc++-v3/testsuite/24_iterators/reverse_iterator/100639.cc > b/libstdc++-v3/testsuite/24_iterators/reverse_iterator/100639.cc > new file mode 100644 > index 00000000000..358d91dfef1 > --- /dev/null > +++ b/libstdc++-v3/testsuite/24_iterators/reverse_iterator/100639.cc > @@ -0,0 +1,37 @@ > +// Copyright (C) 2021 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=c++2a" } > +// { dg-do compile { target c++2a } } > + > +// PR libstdc++/100639 > + > +#include <iterator> > +#include <ranges> > + > +void > +test01() > +{ > + using iter = std::ranges::iterator_t<std::ranges::iota_view<long long>>; > + using riter = std::reverse_iterator<iter>; > + static_assert(std::same_as<std::iter_reference_t<iter>, > + std::iter_reference_t<riter>>); > + static_assert(std::same_as<std::iter_value_t<iter>, > + std::iter_value_t<riter>>); > + static_assert(std::same_as<std::iter_difference_t<iter>, > + std::iter_difference_t<riter>>); > +} > diff --git a/libstdc++-v3/testsuite/std/ranges/adaptors/reverse.cc > b/libstdc++-v3/testsuite/std/ranges/adaptors/reverse.cc > index 47e34eb6581..7f1bde1d5d5 100644 > --- a/libstdc++-v3/testsuite/std/ranges/adaptors/reverse.cc > +++ b/libstdc++-v3/testsuite/std/ranges/adaptors/reverse.cc > @@ -161,6 +161,17 @@ test07() > static_assert(!requires { 0 | reverse; }); > } > > +void > +test08() > +{ > + // PR libstdc++/100639 > + for (auto val > + : views::iota(1701ll, 3000ll) > + | views::reverse > + | views::take(5)) > + ; > +} > + > int > main() > { > @@ -171,4 +182,5 @@ main() > test05(); > test06(); > test07(); > + test08(); > } > -- > 2.32.0.rc0 > >
