[Bug c++/77923] New: GCC emits "declares nothing" diagnostic on meaningful declarations.

[eric at efcs dot ca]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77923

            Bug ID: 77923
           Summary: GCC emits "declares nothing" diagnostic on meaningful
                    declarations.
           Product: gcc
           Version: 7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: eric at efcs dot ca
  Target Milestone: ---

I ran into this error defining a typedef for "struct ::stat" where "stat" names
both a function and type on POSIX systems.

Reduced reproducer:
// g++ -std=c++14 -Werror test.cpp
struct foo {};
void foo() {}
using FooType = struct ::foo; // emits error {{declaration 'struct ::foo' does
not declare anything}}