[Bug libstdc++/59665] New: User code can cause ambiguous references to "std" in libstdc++

[fanael4 at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59665

            Bug ID: 59665
           Summary: User code can cause ambiguous references to "std" in
                    libstdc++
           Product: gcc
           Version: 4.9.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libstdc++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: fanael4 at gmail dot com

The following PURE EVIL but legal code:

namespace foo { namespace std {} }
using namespace foo;
#include <algorithm>

causes the compiler to spew out lots of "error: reference to 'std' is
ambiguous" errors deep in the bowels of libstdc++, for rather obvious reasons.
Granted, this is code is worse than reload, but it's legal, and as such
shouldn't break the standard library.