Why can't iterator methods take either 'ref' or 'out' parameters?

Question

I tried this earlier today:

public interface IFoo
{
    IEnumerable GetItems_A( ref int somethingElse );
    IEnumerable GetItems_B( ref in         


        

Answer 1

Others have explained why your iterator can't have a ref parameter. Here's a simple alternative:

public interface IFoo
{
    IEnumerable GetItems( int[] box );
    ...
}

public class Bar : IFoo
{
    public IEnumerable GetItems( int[] box )
    {
        int value = box[0];
        // use and change value and yield to your heart's content
        box[0] = value;
    }
}

If you have several items to pass in and out, define a class to hold them.