Imported Upstream version 4.0.0~alpha1

Former-commit-id: 806294f5ded97629b74c85c09952f2a74fe182d9

external/referencesource/mscorlib/system/empty.cs

@@ -0,0 +1,40 @@
+using System.Diagnostics.Contracts;
+// ==++==
+// 
+//   Copyright (c) Microsoft Corporation.  All rights reserved.
+// 
+// ==--==
+////////////////////////////////////////////////////////////////////////////////
+// Empty
+//    This class represents an empty variant
+////////////////////////////////////////////////////////////////////////////////
+
+namespace System {
+    
+    using System;
+    using System.Runtime.Remoting;
+    using System.Runtime.Serialization;
+
+    [Serializable]
+    internal sealed class Empty : ISerializable
+    {
+        private Empty() {
+        }
+    
+        public static readonly Empty Value = new Empty();
+        
+        public override String ToString()
+        {
+            return String.Empty;
+        }
+    
+        [System.Security.SecurityCritical]  // auto-generated
+        public void GetObjectData(SerializationInfo info, StreamingContext context) {
+            if (info==null) {
+                throw new ArgumentNullException("info");
+            }
+            Contract.EndContractBlock();
+            UnitySerializationHolder.GetUnitySerializationInfo(info, UnitySerializationHolder.EmptyUnity, null, null);
+        }
+    }
+}