Can serialization serialize a pointer of a class?

[ppzzyy11]

#include <boost/archive/text_oarchive.hpp>
#include <boost/archive/text_iarchive.hpp>
#include <iostream>
#include <sstream>

std::stringstream ss;

class Int{
public:
    int a;
};

class animal
{
public:
  animal() = default;
  animal(int legs) : legs_{legs} {}
  int legs() const { return legs_; }

public:
  friend class boost::serialization::access;

  template <typename Archive>
  void serialize(Archive &ar, const unsigned int version) { ar & legs_; }

  int legs_;
  int *ptr = nullptr;
  Int int_{30};
  Int* int_ptr = nullptr;
};

void save()
{
  boost::archive::text_oarchive oa{ss};
  animal *a = new animal{4};
  a->ptr = new int(100);
  a->int_ptr = new Int{20};
  oa << a;
  std::cout << std::hex << a << '\n';
  delete a;
}

void load()
{
  boost::archive::text_iarchive ia{ss};
  animal *a;
  ia >> a;
  std::cout << std::hex << a << '\n';
  std::cout << std::dec << a->legs() << '\n';
  std::cout<<(a->ptr)<<"a"<<'\n';;//ptr is nullptr....
  std::cout<<a->int_.a<<"\t"<<(a->int_ptr?a->int_ptr->a:0)<<std::endl;;
  delete a;
}

int main()
{
  save();
  load();
}

The result is below. int ptr and Int are both nullptr.

0x60000067c000
0x60000067c020
4
0x0a
30  0

[gucoi]

your serialize function not to serialize ptr, so deserialize not contain the ptr. you can try this like below

template void serialize(Archive &ar, const unsigned int version) { ar & legs_; ar & ptr; ...}

[robertramey]

This is addressed in detail in the documentation for the Boost serialization library.