Return value from Var must be matching type

So it's the not the definition of the viewport that needs changing just the type of variable returned?
SSwift, and you don't want to write a simple function out of principle?

Function getviewport_float(x# Var,y# Var, w# Var,h# Var)
  GetViewport(x1,y1,w1,h1)
  x#=Float(x1)
  y#=Float(y1)
  w#=Float(w1)
  h#=Float(h1)
End Function