Simplify serialization std :: unique_ptr

Question

Does the serialization initialization library support std :: unique_ptr serialization? I tried to compile the code below, but if I turn on boost :: archive :: text_oarchive oa (ofs); oa <g; ,

the compiler (btw gcc4.7 with -std = C ++ 11 flag) throws an error

/usr/include/boost/serialization/access.hpp:118:9: error: 'class std :: unique_ptr does not have a name named' serialize

#include <iostream> #include <memory> #include <fstream> #include <boost/archive/text_oarchive.hpp> #include <boost/archive/text_iarchive.hpp> class MyDegrees { public: void setDeg(int d){deg = d;} int getDeg()const {return deg;} private: friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar & deg; } int deg; }; class gps_position { private: friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar & degrees; } std::unique_ptr<MyDegrees> degrees; public: gps_position(): degrees(std::unique_ptr<MyDegrees>(new MyDegrees)){}; void setDeg(int d){degrees->setDeg(d);} int getDeg() const {return degrees->getDeg();} }; int main() { std::ofstream ofs("filename"); gps_position g; g.setDeg(45); std::cout<<g.getDeg()<<std::endl; {// compiler error, fine if commented out boost::archive::text_oarchive oa(ofs); oa << g; } return 0; } 

Answer 1

No, there is no adaptation. You will need to provide a non-intrusive adapter yourself. See the tutorial here to see how to do this.

Answer 2

as mentioned by pmr , I managed to find the following solution, and at first glance everything works. In the hope that someone will find this useful:

 #include <iostream> #include <memory> #include <fstream> #include <boost/archive/text_oarchive.hpp> #include <boost/archive/text_iarchive.hpp> namespace boost { namespace serialization { template<class Archive, class T> inline void save( Archive & ar, const std::unique_ptr< T > &t, const unsigned int /*file_version*/ ){ // only the raw pointer has to be saved const T * const base_pointer = t.get(); ar & BOOST_SERIALIZATION_NVP(base_pointer); } template<class Archive, class T> inline void load( Archive & ar, std::unique_ptr< T > &t, const unsigned int /*file_version*/ ){ T *base_pointer; ar & BOOST_SERIALIZATION_NVP(base_pointer); t.reset(base_pointer); } template<class Archive, class T> inline void serialize( Archive & ar, std::unique_ptr< T > &t, const unsigned int file_version ){ boost::serialization::split_free(ar, t, file_version); } } // namespace serialization } // namespace boost class MyDegrees { public: void setDeg(int d){deg = d;} int getDeg()const {return deg;} private: friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar & deg; } int deg; }; class gps_position { private: friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar & degrees; } std::unique_ptr<MyDegrees> degrees; public: gps_position(): degrees(std::unique_ptr<MyDegrees>(new MyDegrees)){}; void setDeg(int d){degrees->setDeg(d);} int getDeg() const {return degrees->getDeg();} }; int main() { std::ofstream ofs("filename"); gps_position g; g.setDeg(45); std::cout<<g.getDeg()<<std::endl; { boost::archive::text_oarchive oa(ofs); oa << g; } gps_position newg; { std::ifstream ifs("filename"); boost::archive::text_iarchive ia(ifs); ia >> newg; std::cout<<newg.getDeg()<<std::endl; } return 0; } 

Answer 3

I'm not sure how to interpret this list , but it looks like support has been added through 1.48. I am using 1.58 and it is included. Simply

 #include <boost/serialization/unique_ptr.hpp> 

and then it will work as follows:

 #include <memory> #include <boost/archive/text_oarchive.hpp> #include <boost/archive/text_iarchive.hpp> #include <boost/serialization/unique_ptr.hpp> #include <fstream> class Point { public: Point() { } float x = 1.; float y = 2.; float z = 3.; private: friend class boost::serialization::access; template<class TArchive> void serialize(TArchive & archive, const unsigned int version) { archive & x; archive & y; archive & z; } }; void ValidUniquePointer() { std::unique_ptr<Point> p(new Point()); std::ofstream outputStream("test.txt"); boost::archive::text_oarchive outputArchive(outputStream); outputArchive << p; outputStream.close(); // read from a text archive std::unique_ptr<Point> pointRead; std::ifstream inputStream("test.txt"); boost::archive::text_iarchive inputArchive(inputStream); inputArchive >> pointRead; std::cout << pointRead->x << " " << pointRead->y << " " << pointRead->z << std::endl; } void NullUniquePointer() { std::unique_ptr<Point> p; std::ofstream outputStream("test.txt"); boost::archive::text_oarchive outputArchive(outputStream); outputArchive << p; outputStream.close(); // read from a text archive std::unique_ptr<Point> pointRead; std::ifstream inputStream("test.txt"); boost::archive::text_iarchive inputArchive(inputStream); inputArchive >> pointRead; if(pointRead != nullptr) { std::cout << pointRead->x << " " << pointRead->y << " " << pointRead->z << std::endl; } else { std::cout << "Pointer is null!" << std::endl; } } int main() { ValidUniquePointer(); NullUniquePointer(); return 0; } 

Answer 4

The latest versions of boost syntax provide support for all types of smart std pointers.

Answer 5

Boost now supports smart pointers, you can #include the header file for Unique_Ptr.

  #include <boost/serialization/unique_ptr.hpp>