# include <cerrno>
# include <climits>
#else
-# ifdef HAVE_STDDEF_H
-# include <stddef.h>
-# endif
-# ifdef HAVE_STDLIB_H
-# include <stdio.h>
-# endif
-# ifdef HAVE_STDLIB_H
-# include <stdlib.h>
-# endif
+# include <stddef.h>
+# include <stdio.h>
+# include <stdlib.h>
# include <string.h>
-# ifdef HAVE_TIME_H
-# include <time.h>
-# endif
-# ifdef HAVE_ERRNO_H
-# include <errno.h>
-# endif
-# ifdef HAVE_LIMITS_H
-# include <limits.h>
-# endif
+# include <time.h>
+# include <errno.h>
+# include <limits.h>
#endif
#ifdef HAVE_SYS_UN_H
# include <sys/time.h>
#endif
-#ifdef HAVE_FCNTL_H
-# include <fcntl.h>
-#endif
-
-#ifdef HAVE_SYS_TYPES_H
-# include <sys/types.h>
-#endif
+#include <fcntl.h>
+#include <sys/types.h>
#ifdef HAVE_UNISTD_H
# include <unistd.h>