//******************************************************************************************************//  TransformEqualityComparer.cs - Gbtc////  Copyright © 2015, Grid Protection Alliance.  All Rights Reserved.////  Licensed to the Grid Protection Alliance (GPA) under one or more contributor license agreements. See//  the NOTICE file distributed with this work for additional information regarding copyright ownership.//  The GPA licenses this file to you under the MIT License (MIT), the "License"; you may//  not use this file except in compliance with the License. You may obtain a copy of the License at:////      http://opensource.org/licenses/MIT////  Unless agreed to in writing, the subject software distributed under the License is distributed on an//  "AS-IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. Refer to the//  License for the specific language governing permissions and limitations.////  Code Modification History://  ----------------------------------------------------------------------------------------------------//  08/24/2015 - Stephen C. Wills//       Generated original version of source code.////****************************************************************************************************** using System;using System.Collections.Generic; namespace GSF{    /// <summary>    /// Equality comparer that compares objects by the results of a transformation.    /// </summary>    /// <typeparam name="T">The type of the source objects to be compared.</typeparam>    public class TransformEqualityComparer<T> : IEqualityComparer<T>    {        #region [ Members ]         // Fields        private Func<T, object> m_transformFunction;         #endregion         #region [ Constructors ]         /// <summary>        /// Creates a new instance of the <see cref="TransformEqualityComparer{T}"/> class.        /// </summary>        /// <param name="transformFunction">The function used to transform source objects to the type used for comparison.</param>        public TransformEqualityComparer(Func<T, object> transformFunction)        {            if ((object)transformFunction == null)                throw new ArgumentNullException(nameof(transformFunction));             m_transformFunction = transformFunction;        }         #endregion         #region [ Methods ]         /// <summary>        /// Determines whether the specified objects are equal.        /// </summary>        /// <param name="x">The first object of type <typeparamref name="T"/> to compare.</param>        /// <param name="y">The second object of type <typeparamref name="T"/> to compare.</param>        /// <returns>        /// true if the specified objects are equal; otherwise, false.        /// </returns>        public bool Equals(T x, T y)        {            return Equals(Transform(x), Transform(y));        }         /// <summary>        /// Returns a hash code for the specified object.        /// </summary>        /// <param name="obj">The <see cref="System.Object"/> for which a hash code is to be returned.</param>        /// <returns>        /// A hash code for the specified object.        /// </returns>        /// <exception cref="System.ArgumentNullException">The type of <paramref name="obj"/> is a reference type and <paramref name="obj"/> is null.</exception>        public int GetHashCode(T obj)        {            return Transform(obj).GetHashCode();        }         // Applies the transformation function to the        // given source object and returns the result.        private object Transform(T obj)        {            return m_transformFunction(obj);        }         #endregion    }}