Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.Activities/System/Activities/Expressions/Not.cs

@@ -0,0 +1,51 @@
+//----------------------------------------------------------------
+// Copyright (c) Microsoft Corporation.  All rights reserved.
+//----------------------------------------------------------------
+
+namespace System.Activities.Expressions
+{
+    using System.Activities;
+    using System.Activities.Validation;
+    using System.ComponentModel;
+    using System.Diagnostics.CodeAnalysis;
+    using System.Linq.Expressions;
+    using System.Runtime;
+
+    [SuppressMessage(FxCop.Category.Naming, FxCop.Rule.IdentifiersShouldNotMatchKeywords,
+        Justification = "Optimizing for XAML naming. VB imperative users will [] qualify (e.g. New [Not])")]
+    public sealed class Not<TOperand, TResult> : CodeActivity<TResult>
+    {
+        //Lock is not needed for operationFunction here. The reason is that delegates for a given Not<TLeft, TRight, TResult> are the same.
+        //It's possible that 2 threads are assigning the operationFucntion at the same time. But it's okay because the compiled codes are the same.
+        static Func<TOperand, TResult> operationFunction;
+
+        [RequiredArgument]
+        [DefaultValue(null)]
+        public InArgument<TOperand> Operand
+        {
+            get;
+            set;
+        }
+
+
+        protected override void CacheMetadata(CodeActivityMetadata metadata)
+        {
+            UnaryExpressionHelper.OnGetArguments(metadata, this.Operand);
+
+            if (operationFunction == null)
+            {
+                ValidationError validationError;
+                if (!UnaryExpressionHelper.TryGenerateLinqDelegate(ExpressionType.Not, out operationFunction, out validationError))
+                {
+                    metadata.AddValidationError(validationError);
+                }
+            }
+        }
+        protected override TResult Execute(CodeActivityContext context)
+        {
+            Fx.Assert(operationFunction != null, "OperationFunction must exist.");
+            TOperand operandValue = this.Operand.Get(context);
+            return operationFunction(operandValue);
+        }
+    }
+}