typedef struct CbCSysFile<Type, Impl>{
   struct CbCSysFile* cbc_file;
   struct UInteger* num;
   int n;
   char *p;
   struct file *f;
   __code file_read(__code next(...));
   __code cbc_ret(Impl* cbc_sys_file, UInteger* num);
   __code next(...);
} CbCSysFile;