+/*
+ * Copyright © 2023 Nick Bowler
+ *
+ * Simplified mbsnwidth for test purposes.
+ *
+ * License WTFPL2: Do What The Fuck You Want To Public License, version 2.
+ * This is free software: you are free to do what the fuck you want to.
+ * There is NO WARRANTY, to the extent permitted by law.
+ */
+
+#ifndef TEST_NLS_MBSWIDTH_H_
+#define TEST_NLS_MBSWIDTH_H_
+
+#include <stddef.h>
+
+int mbsnwidth(const char *buf, size_t n, int flags);
+
+#endif