Avoid ref keyword in Extensions method

[KeyserDSoze]

Hi everyone, I need an help. I have a method like this one.

       public void Method()
         {
            int[] x = new int[3] { 1, 2, 3 };
            x.RemoveElementAt(2, out var w);
//length 2 instead of 3
           Assert.True(x.Length == 2);
         }

How can I create an extension method to allow the change of reference without ref keyword?

        public unsafe static bool RemoveElementAt(this IEnumerable entities, int index, out object? value)
        {
            if (entities is Array array)
            {
                IList newArray = Array.CreateInstance(array.GetType().GetElementType()!, array.Length - 1);
                IList oldArray = array;
                int adder = 0;
                value = null;
                for (int i = 0; i < oldArray.Count; i++)
                {
                    if (i != index)
                        newArray[i - adder] = oldArray[i];
                    else
                    {
                        adder = 1;
                        value = oldArray[i];
                    }
                }
                IList* oldPointer = &oldArray;
                IList* newPointer = &newArray;
                oldPointer = newPointer;
                //here, how can I pass the new reference to the older value?
            }
            else if (entities is IList list)
            {
                value = list[index];
                list.RemoveAt(index);
            }
            else
            {
                value = null;
                return false;
            }
            return true;
        }

How can I modify the value outside the extension method?

[333fred]

As was discussed on the community discord, this isn't possible. Only value types can have an extension method that takes a ref this parameter.

[KeyserDSoze]

In the end, to avoid the use of IL code or something similar, I went for out keyword, in my opinion more usable than ref or other mechanisms.

 public static bool RemoveElementAt(this IEnumerable entities, int index, out IEnumerable newEntities, out object? value)
        {
            if (entities is Array array)
            {
                IList newArray = Array.CreateInstance(array.GetType().GetElementType()!, array.Length - 1);
                IList oldArray = array;
                int adder = 0;
                value = null;
                for (int i = 0; i < oldArray.Count; i++)
                {
                    if (i != index)
                        newArray[i - adder] = oldArray[i];
                    else
                    {
                        adder = 1;
                        value = oldArray[i];
                    }
                }
                newEntities = newArray;
            }
            else if (entities is IList list)
            {
                value = list[index];
                list.RemoveAt(index);
                newEntities = list;
            }
            else
            {
                value = null;
                newEntities = null!;
                return false;
            }
            return true;
        }

[XNTEABDSC]

[FaustVX]

As @333fred (#6813 (comment)) said, only struct can have this ref parameters