Multiple declarations in a C++ namespace

[Paul O'Neil via Digitalmars-d-learn]

I'm trying to bind to some C++ code, but when I compile the D side,
there are errors.  Here's my reduced test case:

// C++
namespace ns {
  void func1();
  void func2();
}

// D
module cpp;

extern(C++, ns) void func1();
extern(C++, ns) void func2()

dmd says:cpp_test.d(4): Error: namespace cpp.ns conflicts with namespace
cpp.ns at cpp_test.d(3)

What does this mean and how do I fix it?

Thanks!
-- 
Paul O'Neil
Github / IRC: todayman