+#define XCONCAT5(a,b,c,d,e) CONCAT5(a,b,c,d,e)
+#define XCONCAT6(a,b,c,d,e,f) CONCAT6(a,b,c,d,e,f)
+
+/* Note the layer of indirection here is typically used to allow
+ stringification of the expansion of macros. I.e. "#define foo
+ bar", "XSTRING(foo)", to yield "bar". Be aware that this only
+ works for __STDC__, not for traditional C which will still resolve
+ to "foo". */