TryGetElementFromEnd< TSource >()

static bool System.Linq.Enumerable.TryGetElementFromEnd< TSource > ( IEnumerable< TSource > source, int indexFromEnd, [MaybeNullWhen(false)] out TSource element )

inlinestaticprivate

Definition at line 4724 of file Enumerable.cs.

    {
        if (indexFromEnd > 0)
        {
            using IEnumerator<TSource> enumerator = source.GetEnumerator();
            if (enumerator.MoveNext())
            {
                Queue<TSource> queue = new Queue<TSource>();
                queue.Enqueue(enumerator.Current);
                while (enumerator.MoveNext())
                {
                    if (queue.Count == indexFromEnd)
                    {
                        queue.Dequeue();
                    }
                    queue.Enqueue(enumerator.Current);
                }
                if (queue.Count == indexFromEnd)
                {
                    element = queue.Dequeue();
                    return true;
                }
            }
        }
        element = default(TSource);
        return false;
    }

References System.Collections.Generic.Dictionary< TKey, TValue >.Count, System.Collections.Generic.Dictionary< TKey, TValue >.GetEnumerator(), and System.Linq.source.

Referenced by System.Linq.Enumerable.ElementAtOrDefault< TSource >().