[Bug c++/60927] New: Ambiguity not caught when name introduced through using-directive conflicts with previously declared entity

["filip.roseen at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60927

            Bug ID: 60927
           Summary: Ambiguity not caught when name introduced through
                    using-directive conflicts with previously declared
                    entity
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: filip.roseen at gmail dot com

Created attachment 32656
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=32656&action=edit
testcase.cpp

namespace N {
  namespace A {
    int x = 1;
  }
}

struct A {
  static int x;
};

int main () {
  using namespace N;

  A::x = 123;
}

----------------------------------------------------

`gcc` accepts the above even though there's an ambiguity between `N::A::x` and
`A::x` when referenced as `A::x` in `main`.

------------------------------------------------------

[ note: `gcc` treats the `A::x` as referring to `N::A::x`. ]

[ note: `clang` shows the correct behaviour and issues a diagnostic saying that
`A::x` is ambiguous. ]