Here is the _Safe_iterator one.

Doing so I noticed that pointer_traits rebind for __normal_iterator was 
wrong and added tests on it.

For _Safe_iterator maybe I should specialize only when instantiated with 
__normal_iterator ? Or maybe limit to random_access_iterator_tag ?

Whatever the pointer_to implementation is problematic, we can only 
produce singular iterator as I did ifor now.

François

On 28/09/21 9:25 pm, Jonathan Wakely via Libstdc++ wrote:
> This allows std::__to_address to be used with __normal_iterator in
> C++11/14/17 modes. Without the partial specialization the deduced
> pointer_traits::element_type is incorrect, and so the return type of
> __to_address is wrong.
>
> A similar partial specialization is probably needed for
> __gnu_debug::_Safe_iterator.
>
> Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
>
> libstdc++-v3/ChangeLog:
>
> 	* include/bits/stl_iterator.h (pointer_traits): Define partial
> 	specialization for __normal_iterator.
> 	* testsuite/24_iterators/normal_iterator/to_address.cc: New test.
>
> Tested x86_64-linux. Committed to trunk.
>