Generics Puzzler

I just read this Java generics puzzler from Pure Danger Tech. I have felt exactly this pain many times before. The decision to erase types from compiled bytecode causes so much pain. I don't think .NET uses type erasure, so I figured this would be pretty easy in C#:

        static T[] merge<T>(params T[][] arrays)
        {
            int len = 0;
            foreach (T[] array in arrays)
            {
                len += array.Length;
            }
            T[] result = new T[len];
            len = 0;
            foreach (T[] array in arrays)
            {
                foreach (T elem in array)
                {
                    result[len++] = elem;
                }
            }
            return result;
        }