>On an afterthought
>
>>>And if you use 'ref' you are forced to instantiate the objects before the call otherwise it won't compile ; 'out' avoids that....
>
>Nowhere is it written that you have to instantiate the objects before the call - only that they have to be initialized
>
>A null value is ok
>

>	static class Test_RefOut
>	{
>		internal static void Go()
>		{
>			Dictionary<string, string> dict = null;
>
>			int x = GetDictByRef(ref dict);
>
>			Console.WriteLine("result : {0}", dict);
>		}
>
>		static int  GetDictByRef(ref Dictionary<string, string> dict)
>		{
>			//dict = new Dictionary<string, string>();
>			return 2;
>		}
>		
>	}
>

True. OK - back to message 1583810:
" value types : depending on the size of the value type "

What if the parameter is a biggish structure. More bytes to pass there. e.g.

 public struct LotsOfDoubles
    {
        public double a, b, c, d, e, f, g, h, i, j;
    }