#include <stdio.h> static struct sss{ float f; long double snd; } sss; #define _offsetof(st,f) ((char *)&((st *) 16)->f - (char *) 16) int main (void) { printf ("+++Struct float-longdouble:\n"); printf ("size=%d,align=%d,offset-float=%d,offset-longdouble=%d,\nalign-float=%d,align-longdouble=%d\n", sizeof (sss), __alignof__ (sss), _offsetof (struct sss, f), _offsetof (struct sss, snd), __alignof__ (sss.f), __alignof__ (sss.snd)); return 0; }