Why doesn't delegate contravariance work with value types?

Question

This snippet is not compiled in LINQPad.

void Main()
{
    (new[]{0,1,2,3}).Where(IsNull).Dump();
}

static bool IsNull(object arg) { return arg == null; }
<         


        

Answer 1

It doesn't work for an int because there are not objects.

Try:

void Fun()
{
    IEnumerable