// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.

using System.Runtime.CompilerServices;

namespace System.Collections.Generic
{
    // Base interface for all generic enumerators, providing a simple approach
    // to iterating over a collection.
    [Intrinsic]
    public interface IEnumerator<out T> : IDisposable, IEnumerator
        where T : allows ref struct
    {
        // Returns the current element of the enumeration. The returned value is
        // undefined before the first call to MoveNext and following a
        // call to MoveNext that returned false. Multiple calls to
        // GetCurrent with no intervening calls to MoveNext
        // will return the same object.
        new T Current
        {
            get;
        }

        // NOTE: An implementation of an enumerator using a ref struct T will
        // not be able to implement IEnumerator.Current to return that T (as
        // doing so would require boxing). It should throw a NotSupportedException
        // from that property implementation.
    }
}