Re: still no success binding DLL's callback function

[oyster]

Let me ignore the data type first ;) I hope there is a 
VisualBasic-Freebasic-C-Nim data type comparasion sheet
    
    
    type
      Fl_Callback* = proc(widget: ptr Fl_Widget, pData: ptr any):cint {.cdecl.}
    
    proc ButtonClick (button: ptr FL_WIDGET, arg: ptr any):cint {.cdecl.} =
      Fl_WidgetCopyLabel(button, "do it again")
    
    Fl_WidgetSetCallback(Btn, ButtonClick)
    
    
    Run

says 
    
    
    a.nim(45, 27) template/generic instantiation of `ButtonClick` from here
    a.nim(40, 42) Error: cannot instantiate: 'arg:type'
    
    
    Run