Serializing Eigen::Matrix using Cereal library

Question

UPDATED: I managed to get it to work after I googled around and read the doxygen comments in code. Problem was that I missed the cast before using res

Answer 1

Based on @Azoth answer (whom I would like to give the whole credit, anyway), I improved the template a bit to

• work also for Eigen::Array (rather than just Eigen::Matrix);
• not serialize compile-time dimensions (that makes quite some storage difference for e.g. Eigen::Vector3f).

This is the result:

namespace cereal
{
  template  inline
    typename std::enable_if, Archive>::value, void>::type
    save(Archive & ar, Eigen::PlainObjectBase const & m){
      typedef Eigen::PlainObjectBase ArrT;
      if(ArrT::RowsAtCompileTime==Eigen::Dynamic) ar(m.rows());
      if(ArrT::ColsAtCompileTime==Eigen::Dynamic) ar(m.cols());
      ar(binary_data(m.data(),m.size()*sizeof(typename Derived::Scalar)));
    }

  template  inline
    typename std::enable_if, Archive>::value, void>::type
    load(Archive & ar, Eigen::PlainObjectBase & m){
      typedef Eigen::PlainObjectBase ArrT;
      Eigen::Index rows=ArrT::RowsAtCompileTime, cols=ArrT::ColsAtCompileTime;
      if(rows==Eigen::Dynamic) ar(rows);
      if(cols==Eigen::Dynamic) ar(cols);
      m.resize(rows,cols);
      ar(binary_data(m.data(),static_cast(rows*cols*sizeof(typename Derived::Scalar))));
    }
}