Multiline #define madness
Like to write multi-line #define macros but don’t like how the slashes
\\ spoil their look? With the next simple trick of using
/* C-style comments */, you can achieve the same thing in a beautiful manner.
#include <stdio.h>
#define PRINT_TWICE(x) do { /*
*/ printf( /*
*/ "%s %s\n", /*
*/ (x), (x) /*
*/ ); } while (0)
int main() {
PRINT_TWICE("Hello world!");
return 0;
}
And it works!
[user@host ~]$ gcc multiline-madness.c
[user@host ~]$ ./a.out
Hello world! Hello world!
Notice how split pairs of /* and */ hide ends of lines from the preprocessor:
[user@host ~]$ gcc -E multiline-madness.c
...
int main() {
do { printf( "%s %s\n", ("Hello world!"), ("Hello world!") ); } while (0);
return 0;
}