sharpcompress/src/SharpCompress/ReadOnlyCollection.cs

using System;
using System.Collections;
using System.Collections.Generic;

namespace SharpCompress
{
    internal class ReadOnlyCollection<T> : ICollection<T>
    {
        private readonly ICollection<T> collection;

        public ReadOnlyCollection(ICollection<T> collection)
        {
            this.collection = collection;
        }

        public void Add(T item)
        {
            throw new NotSupportedException();
        }

        public void Clear()
        {
            throw new NotSupportedException();
        }

        public bool Contains(T item)
        {
            return collection.Contains(item);
        }

        public void CopyTo(T[] array, int arrayIndex)
        {
            collection.CopyTo(array, arrayIndex);
        }

        public int Count => collection.Count;

        public bool IsReadOnly => true;

        public bool Remove(T item)
        {
            throw new NotSupportedException();
        }

        public IEnumerator<T> GetEnumerator()
        {
            return collection.GetEnumerator();
        }

        IEnumerator IEnumerable.GetEnumerator()
        {
            throw new NotSupportedException();
        }
    }
}