--- /dev/null
+#include <ccan/cast/cast.h>
+#include <stdlib.h>
+
+/* Note: this *isn't* sizeof(char) on all platforms. */
+struct char_struct {
+ char c;
+};
+
+int main(int argc, char *argv[])
+{
+ char ***uc;
+ const
+#ifdef FAIL
+ struct char_struct
+#else
+ char
+#endif
+ ***p = NULL;
+
+ uc = cast_const3(char ***, p);
+ return 0;
+}
+
+#ifdef FAIL
+#if !HAVE_TYPEOF||!HAVE_BUILTIN_CHOOSE_EXPR||!HAVE_BUILTIN_TYPES_COMPATIBLE_P
+#error "Unfortunately we don't fail if cast_const can only use size"
+#endif
+#endif