[Bug c++/63378] decltype and access control issues

[roger.ferrer at bsc dot es]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63378

--- Comment #1 from Roger Ferrer Ibanez <roger.ferrer at bsc dot es> ---
Created attachment 33578
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=33578&action=edit
Testcase