Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.Activities/System/Activities/Expressions/UnaryExpressionHelper.cs

@@ -0,0 +1,53 @@
+//----------------------------------------------------------------
+// Copyright (c) Microsoft Corporation.  All rights reserved.
+//----------------------------------------------------------------
+
+namespace System.Activities.Expressions
+{
+    using System.Activities.Validation;
+    using System.Collections.ObjectModel;
+    using System.Linq.Expressions;
+    using System.Runtime;
+
+    static class UnaryExpressionHelper
+    {
+        public static void OnGetArguments<TOperand>(CodeActivityMetadata metadata, InArgument<TOperand> operand)
+        {
+            RuntimeArgument operandArgument = new RuntimeArgument("Operand", typeof(TOperand), ArgumentDirection.In, true);
+            metadata.Bind(operand, operandArgument);
+
+            metadata.SetArgumentsCollection(
+                new Collection<RuntimeArgument>
+                {
+                    operandArgument
+                });
+        }
+
+        public static bool TryGenerateLinqDelegate<TOperand, TResult>(ExpressionType operatorType, out Func<TOperand, TResult> operation, out ValidationError validationError)
+        {
+            operation = null;
+            validationError = null;
+
+            ParameterExpression operandParameter = Expression.Parameter(typeof(TOperand), "operand");
+            try
+            {
+                UnaryExpression unaryExpression = Expression.MakeUnary(operatorType, operandParameter, typeof(TResult));
+                Expression expressionToCompile = OperatorPermissionHelper.InjectReflectionPermissionIfNecessary(unaryExpression.Method, unaryExpression);
+                Expression<Func<TOperand, TResult>> lambdaExpression = Expression.Lambda<Func<TOperand, TResult>>(expressionToCompile, operandParameter);
+                operation = lambdaExpression.Compile();
+                return true;
+            }
+            catch (Exception e)
+            {
+                if (Fx.IsFatal(e))
+                {
+                    throw;
+                }
+
+                validationError = new ValidationError(e.Message);
+                return false;
+            }
+        }
+    }
+
+}