message: removed missing serialisation from this branch
diff: @@ -259,12 +259,6 @@ struct residue : public main_branch {
  residue(const main_branch& m)
  : main_branch(m) {
  }
  -
  - friend class boost::serialization::access;
  - template<class Archive>
  - void serialize(Archive& ar, const unsigned version) {
  - ar & boost::serialization::base_object<main_branch>(*this);
  - }
  };
  enum distance_type {
  