--*/
-#include <string.h>
-#include <stdio.h>
-#include <assert.h>
-#include <limits.h>
-#include "libc-extension.hh"
-#include "string.hh"
#include "string-convert.hh"
+
+#include <cstring>
+#include <cstdio>
+
+#include "libc-extension.hh"
#include "rational.hh"
#include "array.hh"