How to declare optional function argument with empty array default value in VBA?

Question

I am trying to build the routine below. The last argument of the routine is an optional array, by default it should have two empty strings. The declaration below doesn't work, it gives me this error: Compile error: Constant expression required

Public Sub CreateReport(rpt As Report, rptSelectFLDS As Variant, _
                        rptWhereConds As Dictionary, _
                        Optional rptTopSelect As Variant = Array("", ""))

Answer 1

How about just checking to see if the argument IsMissing()?

Public Sub CreateReport(rpt As Report, rptSelectFLDS As Variant, _
                        rptWhereConds As Dictionary, _
                        Optional rptTopSelect As Variant)

    If IsMissing(rptTopSelect) Then rptTopSelect = Array("", "")