[Bug c++/78825] missing error for template partial specialization using template alias type

[mattia.bonaducci at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78825

--- Comment #1 from Maciej Załucki <mattia.bonaducci at gmail dot com> ---
My first thought was that it's bug introduced with N3651 support
(C++14 variable templates) to GCC 5 and partially fixed in GCC 5.2.