1  #include <stddef.h>
       2  
       3  extern void *wrapped_malloc (size_t size);
       4  extern void wrapped_free (void *ptr);
       5  
       6  typedef struct boxed_int
       7  {
       8    int i;
       9  } boxed_int;
      10  
      11  extern boxed_int *make_boxed_int (int i);
      12  extern void free_boxed_int (boxed_int *bi);