+void buffer_splice(buffer_t *, ssize_t pos, ssize_t len, const void *, ssize_t);
+
+ssize_t buffer_addvf(buffer_t *buf, const char *fmt, va_list)
+ __attribute__((format(printf, 2, 0)));
+
+ssize_t buffer_addf(buffer_t *buf, const char *fmt, ...)
+ __attribute__((format(printf, 2, 3)));
+