How do I temporarily disable a macro expansion in C/C++?

Question

For some reason I need to temporarily disable some macros in a header file and the #undef MACRONAME will make the code compile but it will undef the existing ma

Answer 1

EDIT:

You may think that it's that easy:

#ifdef macro
#define DISABLED_macro macro
#undef macro
#endif

// do what you want with macro

#ifdef DISABLED_macro
#define macro DISABLED_macro
#endif

But it's not (like the following example demonstrates)!

#include 
#include 

#include 

#ifdef max
#define DISABLED_max max
#undef max
#endif

int main()
{
    std::cout << std::numeric_limits::max() << std::endl;

#ifdef DISABLED_max
#define max DISABLED_max
#endif

    std::cout << max(15,3) << std::endl;  // error C3861: "max": identifier not found
    return 0;
}

Using #undef on the macro and re-including the original header is also not likely to work, because of the header guards. So what's left is using the push_macro/pop_macro #pragma directives.

#pragma push_macro("MACRO")
#undef MACRO
// do what you want
#pragma pop_macro("MACR")