// Minimal compiler test for C compiler.
//
// Semantic mistakes like these are common enough that any compiler MUST produce warnings
// like those in the comments if it is to be used for more than "hello, world".

int
main (void)
{
  int a = 123, b = 7654;

  a ^= b ^= a ^= b;             // warning: operation on a may be undefined

  return a;
}