[Bug c++/42329] Deduction of template template argument via base class fails

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=42329

--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> ---
A more recent EDG than Comeau 4.3 still accepts this, Clang gives the same
errors as GCC.