[Bug libstdc++/78483] New: Error: reference to 'on_exit' is ambiguous

[krzysztof at jusiak dot net]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78483

            Bug ID: 78483
           Summary: Error: reference to 'on_exit' is ambiguous
           Product: gcc
           Version: 6.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libstdc++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: krzysztof at jusiak dot net
  Target Milestone: ---

It seems that including cstdlib is not adding std namespace, at least for
on_exit function, which causes ambiguity with user defined type with the same
name.

Example.

#include <cstdlib>

namespace test {
struct on_exit {}; }

int main() {
  using namespace test;
  on_exit{}; // error
}

Full example here:
http://melpon.org/wandbox/permlink/3ddFqVlBGxbB64mF