*result = new nsSVGLength(value, unit); if (!*result)
*result = nsnull; nsSVGLength *pl = new nsSVGLength(); if (!pl)
NS_NewSVGLength(nsISVGLength** result,                float value,                PRUint16 unit){  *result = new nsSVGLength(value, unit);  if (!*result)    return NS_ERROR_OUT_OF_MEMORY;  NS_ADDREF(*result);  return NS_OK;}