[Bug c++/78986] New: template inner classes are not affected by visibility specifiers

[michele.caini at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78986

            Bug ID: 78986
           Summary: template inner classes are not affected by visibility
                    specifiers
           Product: gcc
           Version: 7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: michele.caini at gmail dot com
  Target Milestone: ---

Consider the following code:

    class B { struct T {}; };
    class D: B { template<typename> struct U: T {}; };
    int main() {}

GCC accepts it, but it shouldn't for T is private in B and U cannot inherit
from it in D.
GCC correctly rejects the code below:

    class B { struct T {}; };
    class D: B { struct U: T {}; };
    int main() {}