ArrayEnumerator.cs

public ref struct ArrayEnumerator<T>
    where T: struct
{
    private int _index;
    private readonly int _length;
    private readonly T[] _array;

    [MethodImpl(MethodImplOptions.AggressiveInlining)]
    public ArrayEnumerator(T[] array)
    {
        _index = 0;
        _array = array;
        _length = _array.Length;
    }

    [MethodImpl(MethodImplOptions.AggressiveInlining)]
    public bool MoveNext() => ++_index < _length;

    public readonly ref T Current
    {
        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        get => ref _array[_index];
    }

    [MethodImpl(MethodImplOptions.AggressiveInlining)]
    public readonly ArrayEnumerator<T> GetEnumerator() => this;
}