libstdc++: add missing typename for dependent type in ranges::elements_view [PR100900]

Clang complains about the missing typename. I believe it's not required
in a more complete implementation of C++, but it's nicer to support
less complete implementations.

	PR libstdc++/100900

libstdc++-v3/ChangeLog:

	* include/std/ranges (elements_view::__iter_cat::_S_iter_cat):
	Add missing typename.

(cherry picked from commit 5e2e15f212e2458a1258b8c856895c755460bc6b)

diff --git a/libstdc++-v3/include/std/ranges b/libstdc++-v3/include/std/ranges
index ae3cd7fbc996e27b32360cfee89303078cb35b85..0dd4fb6a9a5e5f1cabb65357fef40a83e5702d43 100644 (file)
--- a/libstdc++-v3/include/std/ranges
+++ b/libstdc++-v3/include/std/ranges
@@ -3463,7 +3463,7 @@ namespace views::__adaptor
          static auto _S_iter_cat()
          {
            using _Base = elements_view::_Base<_Const>;
-           using _Cat = iterator_traits<iterator_t<_Base>>::iterator_category;
+           using _Cat = typename iterator_traits<iterator_t<_Base>>::iterator_category;
            using _Res = decltype((std::get<_Nm>(*std::declval<iterator_t<_Base>>())));
            if constexpr (!is_lvalue_reference_v<_Res>)
              return input_iterator_tag{};