Description of problem:


Due to lagging C++20 support in Clang, it fails to compile a function in <ranges>.

This was already fixed in gcc trunk and backported, so it can be fixed by refreshing the branch.

Version-Release number of selected component (if applicable):
gcc-11.1.1-3.fc34

How reproducible:
Always

Steps to Reproduce:
1. write some code using std::ranges::elements_view
2. build it with clang due to https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95137
3. see error

Actual results:

/usr/lib/gcc/x86_64-redhat-linux/11/../../../../include/c++/11/ranges:3392:19: error: missing 'typename' prior to dependent type name 'iterator_traits<iterator_t<_Base>>::iterator_category'
            using _Cat = iterator_traits<iterator_t<_Base>>::iterator_category;


Expected results:


No error.

Additional info:

Fixed upstream and backported to the gcc-11 branch.