See http://www.pixelbeat.org/programming/gcc/static_assert.html
define ASSERT_CONCAT_(a, b) a##b
define ASSERT_CONCAT(a, b) ASSERT_CONCAT_(a, b)
/* These can't be used after statements in c89. */
ifdef __COUNTER__
#define STATIC_ASSERT(e,m) \
{ enum { ASSERT_CONCAT(static_assert_, __COUNTER__) = 1/(!!(e)) }; }
else
/* This can't be used twice on the same line so ensure if using in headers
* that the headers are not included twice (by wrapping in #ifndef...#endif)
* Note it doesn't cause an issue when used on same line of separate modules
* compiled with gcc -combine -fwhole-program. */
#define STATIC_ASSERT(e,m) \
{ enum { ASSERT_CONCAT(assert_line_, __LINE__) = 1/(!!(e)) }; }