+/* Handly macro for suppressing unreferenced-parameter compiler warnings. */
+#ifndef UNUSED
+#define UNUSED(x) (void)(x)
+#endif
+
+/* Compile-time assertion, used for checking compatible compilation options. */
+#ifndef STATIC_ASSERT
+#define STATIC_ASSERT(COND,MSG) typedef char static_assertion_##MSG[(COND)?1:-1];
+#endif
+
+/* Number of required fields to keep track of
+ * (change here or on compiler command line). */
+#ifndef PB_MAX_REQUIRED_FIELDS
+#define PB_MAX_REQUIRED_FIELDS 64
+#endif