pop for a set - is there something prettier?

[HJarausch]

Unfortunately, the built-in (bit) _set_ type doesn't have a _pop_ procedure (as 
does HashSet).

There must be something prettier than
    
    
    proc pop[T]( S:var set[T] ) : T =
      if card(S) == 0 :
        raise newException(IndexDefect,"pop on an empty set")
      var found : T
      for e in S :
        found= e
        break
      S.excl(found)
      found
    
    
    Run

Many thanks for a hint, Helmut