#define _HEADER_MACRO(m) int m = 0 namespace _Header_Ns { class _Header_Object { int _Header_Member; }; float _Header_Global; void _Header_Function() {} using _Header_Alias = int; } // namespace _Header_Ns // #define __header_macro(m) int m = 0 namespace __header_ns { class __header_object { int __header_member; }; float __header_global; void __header_function() {} using __header_alias = int; } // namespace __header_ns // #define header_macro__m(m) int m = 0 namespace header_ns__n { class header_object__o { int header_member__m; }; float header_global__g; void header_function__f() {} using header_alias__a = int; } // namespace header_ns__n // #define _header_macro(m) int m = 0 namespace _header_ns {} class _header_object {}; float _header_global; void _header_function() {} using _header_alias = int;