[PATCH] libstdc++: Fix iterator caching inside range adaptors [PR100479]

[Jonathan Wakely]

On 17/05/21 11:43 -0400, Patrick Palka via Libstdc++ wrote:
>This fixes two issues with our iterator caching as described in detail
>in the PR.  Since r12-336 added the __non_propagating_cache class
>template as part of P2328, this patch just rewrites the _CachedPosition
>partial specialization in terms of this class template.
>
>Tested on x86_64-pc-linux-gnu, does this look OK for trunk? 

OK, thanks.

>Shall we
>also backport this?

I think so, but give it a couple of weeks (or more) on trunk first.