Testing for GCC compile-time constants quickly

std-test.c

/* Tests compile constants in GCC */

#define STR_HELPER(x) #x
#define STR(x) STR_HELPER(x)

#if defined(__STDC_VERSION__)
#pragma message STR(__STDC_VERSION__)
#else
#pragma message "__STDC_VERSION__ not defined"
#endif

#if defined(__STRICT_ANSI__)
#pragma message STR(__STRICT_ANSI__)
#else
#pragma message "__STRICT_ANSI__ not defined"
#endif