EmptyEnumerable.cs :  » PDF » iTextSharp » Org » BouncyCastle » Utilities » Collections » C# / CSharp Open Source

using System;
using System.Collections;

namespace Org.BouncyCastle.Utilities.Collections{
  public sealed class EmptyEnumerable
    : IEnumerable
  {
    public static readonly IEnumerable Instance = new EmptyEnumerable();

    private EmptyEnumerable()
    {
    }

    public IEnumerator GetEnumerator()
    {
      return EmptyEnumerator.Instance;
    }
  }

  public sealed class EmptyEnumerator
    : IEnumerator
  {
    public static readonly IEnumerator Instance = new EmptyEnumerator();

    private EmptyEnumerator()
    {
    }

    public bool MoveNext()
    {
      return false;
    }

    public void Reset()
    {
    }

    public object Current
    {
      get { throw new InvalidOperationException("No elements"); }
    }
  }
}