/usr/include/isset.h is in libowfat-dev 0.29-3.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 | /* this header file comes from libowfat, http://www.fefe.de/libowfat/ */
#ifndef _ISSET_H
#define _ISSET_H
/*
How to check whether a preprocessor symbol is defined or not?
Difficulty: it should work both in the preprocessor:
#if is_set(FOO)
and in C code (and then no code should be generated)
if (is_set(FOO))
We will allow both
#define FOO
and
#define FOO 1
*/
/* Original question posed by Linus Torvalds
* https://plus.google.com/102150693225130002912/posts/9gntjh57dXt
* Solution by comex
* https://gist.github.com/2365372
*/
#define is_set(macro) is_set_(macro)
#define macrotest_1 ,
#define macrotest_ ,
#define is_set_(value) is_set__(macrotest_##value)
#define is_set__(comma) is_set___(comma 1, 0)
#define is_set___(_, v, ...) v
#endif
|