[Bug c++/80841] Fails to match template specialization with polymorphic non-type template argument

[daniel.kruegler at googlemail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80841

--- Comment #3 from Daniel Krügler <daniel.kruegler at googlemail dot com> ---
(In reply to Jason Bell from comment #2)
> Thanks that's a good reduced example.  I've changed it slightly so it works
> with constexpr input.

But that is just adding additional complexity: The constexpr declaration is
unnecessary when you provide an argument of reference type to a non-type
template of reference type.