Check whether function is declared with C preprocessor?

Question

Is it possible to tell the C preprocessor to check whether a function (not a macro) is declared? I tried the following, but it doesn\'t appear to work:

Answer 1

Since the preprocessor is not aware of the language C/C++ (it really only does text-replacement) I would guess that this is not possible. Why do you want to do this? Maybe there is another way.