nsresult SVGPathSegListSMILType::Assign(SMILValue& aDest,
                                        const SMILValue& aSrc) const {
  MOZ_ASSERT(aDest.mType == aSrc.mType, "Incompatible SMIL types");
  MOZ_ASSERT(aDest.mType == this, "Unexpected SMIL value");

  const SVGPathDataAndInfo* src =
      static_cast<const SVGPathDataAndInfo*>(aSrc.mU.mPtr);
  SVGPathDataAndInfo* dest = static_cast<SVGPathDataAndInfo*>(aDest.mU.mPtr);

  return dest->CopyFrom(*src);
}
nsSMILValue
SVGAnimatedPathSegList::SMILAnimatedPathSegList::GetBaseValue() const
{
  // To benefit from Return Value Optimization and avoid copy constructor calls
  // due to our use of return-by-value, we must return the exact same object
  // from ALL return points. This function must only return THIS variable:
  nsSMILValue val;

  nsSMILValue tmp(SVGPathSegListSMILType::Singleton());
  SVGPathDataAndInfo *list = static_cast<SVGPathDataAndInfo*>(tmp.mU.mPtr);
  nsresult rv = list->CopyFrom(mVal->mBaseVal);
  if (NS_SUCCEEDED(rv)) {
    list->SetElement(mElement);
    val = Move(tmp);
  }
  return val;
}