Namespace 'cmb1' causes C++ compilation error

When I try to compile this code:

#include <windows.h>

namespace cmb1 {
}

void main() {}

I get this:

Microsoft (R) 32-bit C/C++ Optimizing Compiler Version 14.00.50727.762 for 80x86
Copyright (C) Microsoft Corporation.  All rights reserved.
a.cc
a.cc(3) : error C2059: syntax error : 'consta开发者_如何学编程nt'
a.cc(3) : error C2143: syntax error : missing ';' before '{'
a.cc(3) : error C2447: '{' : missing function header (old-style formal list?)

Ditto for cmb2, cmb3 and cmb4. I stopped at that point. cm4, btw, compiles just fine.

I tried surrounding the namespace with something else:

namespace dilum {
namespace cmb4 {
}
}

But the compile still failed.

What is going on?

from windows.h:

#define cmb1 0x470
#define cmb2 0x471
#define cmb3 0x472
#define cmb4 0x473
#define cmb5 0x474
#define cmb6 0x475
#define cmb7 0x476
#define cmb8 0x477
#define cmb9 0x478
#define cmb10 0x479
#define cmb11 0x47A
#define cmb12 0x47B
#define cmb13 0x47C
#define cmb14 0x47D
#define cmb15 0x47E
#define cmb16 0x47F

cmb1 may be a macro defined in windows.h. If the macro expands itself to an expression, the compiler sees

namespace <the_expanded_expression> {
}

The constant cmb1 is defined in <windows.h> as follows:

#define cmb1 0x0470

If you are using Visual Studio 2010, you can hover over the red squiggly arrow under cmb1 to see the definition.

Needless to say, namespace 0x0470 { } is not a valid namespace declaration.