Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.ServiceModel/System/ServiceModel/EmptyArray.cs

@@ -0,0 +1,83 @@
+//-----------------------------------------------------------------------------
+// Copyright (c) Microsoft Corporation.  All rights reserved.
+//-----------------------------------------------------------------------------
+
+namespace System.ServiceModel
+{
+    using System;
+    using System.Collections.Generic;
+
+    class EmptyArray<T>
+    {
+        static T[] instance;
+
+        EmptyArray()
+        {
+        }
+
+        internal static T[] Instance
+        {
+            get
+            {
+                if (instance == null)
+                    instance = new T[0];
+                return instance;
+            }
+        }
+
+        internal static T[] Allocate(int n)
+        {
+            if (n == 0)
+                return Instance;
+            else
+                return new T[n];
+        }
+
+        internal static T[] ToArray(IList<T> collection)
+        {
+            if (collection.Count == 0)
+            {
+                return EmptyArray<T>.Instance;
+            }
+            else
+            {
+                T[] array = new T[collection.Count];
+                collection.CopyTo(array, 0);
+                return array;
+            }
+        }
+
+        internal static T[] ToArray(SynchronizedCollection<T> collection)
+        {
+            lock (collection.SyncRoot)
+            {
+                return EmptyArray<T>.ToArray((IList<T>)collection);
+            }
+        }
+    }
+
+    class EmptyArray
+    {
+        static object[] instance = new object[0];
+
+        EmptyArray()
+        {
+        }
+
+        internal static object[] Instance
+        {
+            get
+            {
+                return instance;
+            }
+        }
+
+        internal static object[] Allocate(int n)
+        {
+            if (n == 0)
+                return Instance;
+            else
+                return new object[n];
+        }
+    }
+}