// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
using System.Collections;
 
// This file was generated, please do not edit it directly.
// 
// This file was generated using the common file located at:
 
namespace MS.Internal
{
    /// <summary>
    ///     Helper WeakHashSet class implemented using WeakHashTable
    /// </summary>
    internal class WeakHashSet<T> : ICollection<T> where T : class
    {
        #region ICollection<T> Members
 
        public void Add(T item)
        {
            if (!_hashTable.ContainsKey(item))
            {
                _hashTable.SetWeak(item, null);
            }
        }
 
        public void Clear()
        {
            _hashTable.Clear();
        }
 
        public bool Contains(T item)
        {
            return _hashTable.ContainsKey(item);
        }
 
        public void CopyTo(T[] array, int arrayIndex)
        {
            ArgumentOutOfRangeException.ThrowIfNegative(arrayIndex);
            ArgumentNullException.ThrowIfNull(array);
 
            int count = 0;
            foreach (T item in this)
            {
                count++;
            }
 
            ArgumentOutOfRangeException.ThrowIfGreaterThan(arrayIndex, array.Length - count);
 
            foreach (T item in this)
            {
                array[arrayIndex++] = item;
            }
        }
 
        public int Count
        {
            get
            {
                return _hashTable.Count;
            }
        }
 
        public bool IsReadOnly
        {
            get { return false; }
        }
 
        public bool Remove(T item)
        {
            if (_hashTable.ContainsKey(item))
            {
                _hashTable.Remove(item);
                return true;
            }
            return false;
        }
 
        #endregion
 
        #region IEnumerable<T> Members
 
        public IEnumerator<T> GetEnumerator()
        {
            foreach (object key in _hashTable.Keys)
            {
                WeakHashtable.EqualityWeakReference objRef = key as WeakHashtable.EqualityWeakReference;
                if (objRef != null)
                {
                    T obj = objRef.Target as T;
                    if (obj != null)
                    {
                        yield return obj;
                    }
                }
            }
        }
 
        #endregion
 
        #region IEnumerable Members
 
        IEnumerator IEnumerable.GetEnumerator()
        {
            return this.GetEnumerator();
        }
 
        #endregion
 
        #region Private Data
 
        private WeakHashtable _hashTable = new WeakHashtable();
 
        #endregion
    }
}