update Stack implementation to Swift 4 with Xcode 9b4

paulsumit1993 · paulsumit1993 · commit d745696bb7b9 · 2017-07-25T12:05:58.000+05:30
diff --git a/Stack/Stack.playground/Contents.swift b/Stack/Stack.playground/Contents.swift
@@ -1,3 +1,9 @@
+
+// last checked with Xcode 9.0b4
+#if swift(>=4.0)
+print("Hello, Swift 4!")
+#endif
+
 /*
   Stack
 
