The wrong type was being used in the __common_iter_has_arrow constraint, creating a circular dependency where the iterator_traits specialization was needed before it was complete. The correct parameter for the __common_iter_has_arrow concept is the first template argument of the common_iterator, not the common_iterator itself.
* include/bits/stl_iterator.h (__detail::__common_iter_ptr): Change to take parameters of common_iterator, instead of the common_iterator type itself. Fix argument for __common_iter_has_arrow constraint. (iterator_traits<common_iterator<I, S>>::pointer): Adjust. Tested powerpc64le-linux, committed to master.
commit d222d8ec3c100f5c0a6974e7dcee16903f6f0e3a Author: Jonathan Wakely <jwak...@redhat.com> Date: Fri Feb 7 16:46:42 2020 +0000 libstdc++: Fix bug in iterator_traits<common_iterator<S,I>> The wrong type was being used in the __common_iter_has_arrow constraint, creating a circular dependency where the iterator_traits specialization was needed before it was complete. The correct parameter for the __common_iter_has_arrow concept is the first template argument of the common_iterator, not the common_iterator itself. * include/bits/stl_iterator.h (__detail::__common_iter_ptr): Change to take parameters of common_iterator, instead of the common_iterator type itself. Fix argument for __common_iter_has_arrow constraint. (iterator_traits<common_iterator<I, S>>::pointer): Adjust. diff --git a/libstdc++-v3/include/bits/stl_iterator.h b/libstdc++-v3/include/bits/stl_iterator.h index 69c6ae66cdf..46804656801 100644 --- a/libstdc++-v3/include/bits/stl_iterator.h +++ b/libstdc++-v3/include/bits/stl_iterator.h @@ -1738,17 +1738,20 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION namespace __detail { // FIXME: This has to be at namespace-scope because of PR 92103. - template<typename _Iter> + template<typename _It, typename _Sent> struct __common_iter_ptr { using type = void; }; - template<typename _Iter> - requires __detail::__common_iter_has_arrow<_Iter> - struct __common_iter_ptr<_Iter> + template<typename _It, typename _Sent> + requires __detail::__common_iter_has_arrow<_It> + struct __common_iter_ptr<_It, _Sent> { - using type = decltype(std::declval<const _Iter&>().operator->()); + using common_iterator = std::common_iterator<_It, _Sent>; + + using type + = decltype(std::declval<const common_iterator&>().operator->()); }; } // namespace __detail @@ -1762,8 +1765,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION forward_iterator_tag, input_iterator_tag>; using value_type = iter_value_t<_It>; using difference_type = iter_difference_t<_It>; - using pointer = typename - __detail::__common_iter_ptr<common_iterator<_It, _Sent>>::type; + using pointer = typename __detail::__common_iter_ptr<_It, _Sent>::type; using reference = iter_reference_t<_It>; };