using System;
using System.Collections;
using System.Collections.Generic;
using System.Runtime.CompilerServices;

namespace Lucene.Net.Support
{
    /*
	 * Licensed to the Apache Software Foundation (ASF) under one or more
	 * contributor license agreements.  See the NOTICE file distributed with
	 * this work for additional information regarding copyright ownership.
	 * The ASF licenses this file to You under the Apache License, Version 2.0
	 * (the "License"); you may not use this file except in compliance with
	 * the License.  You may obtain a copy of the License at
	 *
	 *     http://www.apache.org/licenses/LICENSE-2.0
	 *
	 * Unless required by applicable law or agreed to in writing, software
	 * distributed under the License is distributed on an "AS IS" BASIS,
	 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	 * See the License for the specific language governing permissions and
	 * limitations under the License.
	 */

#if FEATURE_SERIALIZABLE
    [Serializable]
#endif
    public class IdentityComparer<T> : IEqualityComparer<T>
    {
        public bool Equals(T x, T y)
        {
            return ReferenceEquals(x, y);
        }

        public int GetHashCode(T obj)
        {
            return RuntimeHelpers.GetHashCode(obj);
        }
    }

#if FEATURE_SERIALIZABLE
    [Serializable]
#endif
    public class IdentityComparer : IEqualityComparer
    {
        public new bool Equals(object x, object y)
        {
            return ReferenceEquals(x, y);
        }

        public int GetHashCode(object obj)
        {
            return RuntimeHelpers.GetHashCode(obj);
        }
    }
}