// unionassign.c
// assign a union variable to another union variable


// ------------------ this part works -----------------------
struct S1 {
  int x;
};

struct S2 {
  char p;
};

struct S3 {
  int x1;
  int y1;
};

union U {
  struct S1 s1;
  struct S2 s2;
  struct S3 s3;
};

int main()
{
  union U x,y;
  x.s1.x = 5;
  y = x;
  return y.s1.x - 5;
}



// ------------------- this part fails -------------------
typedef unsigned short int sa_family_t ;
typedef unsigned char uint8_t ;
typedef unsigned short int uint16_t ;
typedef unsigned int uint32_t ;

struct in_addr {
	uint32_t s_addr ;
} ;

struct sockaddr {
	sa_family_t sa_family ;
	char sa_data[14] ;
} ;

struct sockaddr_in {
	sa_family_t sin_family ;
	uint16_t sin_port ;
	struct in_addr sin_addr ;
	unsigned char sin_zero[sizeof(struct sockaddr ) -
		sizeof(unsigned short int ) - sizeof(uint16_t ) -
		sizeof(struct in_addr )] ;
} ;

struct in6_addr {
	union  {
		uint8_t u6_addr8[16] ;
		uint16_t u6_addr16[8] ;
		uint32_t u6_addr32[4] ;
	} in6_u ;
} ;

struct sockaddr_in6 {
	sa_family_t sin6_family ;
	uint16_t sin6_port ;
	uint32_t sin6_flowinfo ;
	struct in6_addr sin6_addr ;
} ;

union sockunion {
	struct sockinet {
		sa_family_t si_family ;
		uint16_t si_port ;
	} su_si ;
	struct sockaddr_in su_sin ;
	struct sockaddr_in6 su_sin6 ;
} ;

int foo()
{
  union sockunion x,y;
  x = y;
  return 3;
}