Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.Activities/System/Activities/VariableModifiersHelper.cs

@@ -0,0 +1,38 @@
+//-----------------------------------------------------------------------------
+// Copyright (c) Microsoft Corporation.  All rights reserved.
+//-----------------------------------------------------------------------------
+
+namespace System.Activities
+{
+    using System;
+    using System.ComponentModel;
+    using System.Runtime;
+
+    static class VariableModifiersHelper
+    {
+        static bool IsDefined(VariableModifiers modifiers)
+        {
+            return (modifiers == VariableModifiers.None ||
+                ((modifiers & (VariableModifiers.Mapped | VariableModifiers.ReadOnly)) == modifiers));
+        }
+
+        public static bool IsReadOnly(VariableModifiers modifiers)
+        {
+            return (modifiers & VariableModifiers.ReadOnly) == VariableModifiers.ReadOnly;
+        }
+
+        public static bool IsMappable(VariableModifiers modifiers)
+        {
+            return (modifiers & VariableModifiers.Mapped) == VariableModifiers.Mapped;
+        }
+
+        public static void Validate(VariableModifiers modifiers, string argumentName)
+        {
+            if (!IsDefined(modifiers))
+            {
+                throw FxTrace.Exception.AsError(
+                    new InvalidEnumArgumentException(argumentName, (int)modifiers, typeof(VariableModifiers)));
+            }
+        }
+    }
+}