trunc-1.c

this is a gcc file, you can download it and learn its usetility, for further detail please look at t

/* Origin: PR c/675 from [e-mail].  */
/* { dg-do compile } */
/* { dg-options "-Wall" } */

#include <stddef.h>

int
main (void)
{
  size_t len;

  len = ~(sizeof (size_t) - 1); /* { dg-bogus "truncated" "bogus truncation warning" } */

  return 0;
}