#include <stdio.h>

typedef struct hoge {
  int foo;
  char* bar;
} hoge;

typedef struct hoge2 {
  int foo;  
  char* bar;
} hoge2;

union UNION{
  struct hoge hoge;
  struct hoge2 hoge2;  
};

int main () {
  hoge hu = {11, "hello"};
  union UNION *unionTest = (union UNION*) &hu;
  //printf("%d\n", unionTest->hoge.foo);
  printf("%d\n", ((hoge*)unionTest)->foo);
  return 0;
}