Testing two macros for equality

[user name]

How would I test two macros for equality? For example:

#include <another_file.h>
#define REQUIRED_VERSION "0.7.41"   // version required for a_newly_implemented_function() in A_class_from_another_file to work

// ...
A_class_from_another_file a;

#if REQUIRED_VERSION == ACTUAL_VERSION_DEFINED_IN_ANOTHER_FILE     // how would I get something like this to work?
std::cout << a.a_newly_implemented_function() << std::endl;
#else
// alternative
#endif

// ... 

When I try that, I get something like this (g++):

error: token ""0.7.41"" is not valid in preprocessor expressions

[helios]

Just what the error says. You can't use strings in preprocessor expressions.
You could do this, though:
#define REQUIRED_VERSION 0741

[user name]

OK, I'll try that.