[Bug libstdc++/102181] std::advance and std::views::iota don't work

[redi at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102181

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Assignee|unassigned at gcc dot gnu.org      |redi at gcc dot gnu.org
     Ever confirmed|0                           |1
         Resolution|INVALID                     |---
   Last reconfirmed|                            |2021-09-02
             Status|RESOLVED                    |ASSIGNED

--- Comment #6 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Reopening, because we can make this Just Work, even though we're not required
to.

--- a/libstdc++-v3/include/bits/stl_iterator_base_funcs.h
+++ b/libstdc++-v3/include/bits/stl_iterator_base_funcs.h
@@ -211,7 +222,11 @@ _GLIBCXX_END_NAMESPACE_CONTAINER
     {
       // concept requirements -- taken care of in __advance
       typename iterator_traits<_InputIterator>::difference_type __d = __n;
+#if __cpp_lib_concepts
+      std::__advance(__i, __d, __detail::__iter_concept<_InputIterator>{});
+#else
       std::__advance(__i, __d, std::__iterator_category(__i));
+#endif
     }

 #if __cplusplus >= 201103L