About Macro

C or C++ is a language that one can always tweak to dig out something helpful but graceless. Below is an example I recently used to solve the problem of one of my colleagues. I think it is not astounding to sophisticated C programmers that macro can make so much trouble.

#include <stdio.h>

#define nameprint2(n)   #n
#define nameprint(n)    nameprint2(n)

 

#define name1()         win
#define name2()         dows
#define name()          windows #define dotH()          .h

 

#define cat3(a,b,c)     a##b##c #define cat2(a,b)       a##b

 

#define incname2    nameprint(cat2(name(),dotH()))

#define incname3    nameprint(cat3(name1(),name2(),dotH())) 

 

#include incname2 //#include incname3

 

int main (void)
{        
    char *p = incname2;         HANDLE h;   // this needs `windows.h' to be included

    printf("%s/n", p);

    return 0;
}