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-rw-r--r--backport-include/backport/magic.h16
1 files changed, 16 insertions, 0 deletions
diff --git a/backport-include/backport/magic.h b/backport-include/backport/magic.h
new file mode 100644
index 0000000..d7e7cc9
--- /dev/null
+++ b/backport-include/backport/magic.h
@@ -0,0 +1,16 @@
+/*
+ * These tricks are taken from
+ * http://efesx.com/2010/07/17/variadic-macro-to-count-number-of-arguments/
+ * and
+ * http://efesx.com/2010/08/31/overloading-macros/
+ */
+
+#define VA_NUM_ARGS(...) VA_NUM_ARGS_IMPL(__VA_ARGS__, 6,5,4,3,2,1)
+#define VA_NUM_ARGS_IMPL(_1,_2,_3,_4,_5,_6,N,...) N
+
+#define macro_dispatcher(func, ...) \
+ macro_dispatcher_(func, VA_NUM_ARGS(__VA_ARGS__))
+#define macro_dispatcher_(func, nargs) \
+ macro_dispatcher__(func, nargs)
+#define macro_dispatcher__(func, nargs) \
+ func ## nargs