[Bug libstdc++/106610] New: elements_view::iterator::iterator_category invokes the operator*() && of the underlying iterator

[hewillk at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106610

            Bug ID: 106610
           Summary: elements_view::iterator::iterator_category invokes the
                    operator*() && of the underlying iterator
           Product: gcc
           Version: 13.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libstdc++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: hewillk at gmail dot com
  Target Milestone: ---

#include <ranges>

struct I {
  using difference_type = std::ptrdiff_t;
  using value_type = std::pair<int, double>;
  value_type& operator*() const &;
  void operator*() && = delete;
  I& operator++();
  I operator++(int);
  bool operator==(const I&) const;
};

int main() {
  std::ranges::input_range auto r = std::ranges::subrange(I{},
std::unreachable_sentinel);
  auto e = r | std::views::keys;
}

https://godbolt.org/z/oW8dP56zv