add foreach.h

foreach.h

@@ -0,0 +1,14 @@
+
+#ifndef foreach
+
+#define foreach_iter_var(var) var ## _iter
+#define foreach(var, val) \
+    for (typeof(val.begin()) foreach_iter_var(var) = (val).begin(), \
+            _ = (val).begin(); \
+            foreach_iter_var(var) != (val).end(); \
+            foreach_iter_var(var)++, _ = (val).begin()) \
+        for (typeof(*foreach_iter_var(var)) var = *foreach_iter_var(var); \
+                _ != (val).end(); \
+                _ = (val).end())
+
+#endif