基类和派生类的代码如下：
class student_info
{
public:
student_info() {}
virtual ~student_info() {}
student_info(const std::string& sn, const std::string& snm, const std::string& sg)
: name_(sn), number_(snm), grade_(sg)
{
}
virtual void print_info() const
{
std::cout << name_ << " " << number_ << " " << grade_ << std::endl;
}
private:
friend class boost::serialization::access;
template<typename Archive>
void serialize(Archive& ar, const unsigned int version)
{
ar & BOOST_SERIALIZATION_NVP(name_);
ar & BOOST_SERIALIZATION_NVP(number_);
ar & BOOST_SERIALIZATION_NVP(grade_);
}
private:
std::string name_;
std::string number_;
std::string grade_;
};
class middle_student : public student_info
{
public:
middle_student() {}
virtual ~middle_student() {}
middle_student(const std::string& sn, const std::string& snm, const std::string& sg, int age)
: student_info(sn, snm, sg), age_(age)
{
}
virtual void print_info()
{
student_info::print_info();
std::cout << age_ << std::endl;
}
private:
friend class boost::serialization::access;
template<typename Archive>
void serialize(Archive& ar, const unsigned int version)
{
ar & boost::serialization::base_object<student_info>(*this);
ar & BOOST_SERIALIZATION_NVP(age_);
}
private:
int age_;
};在派生类中使用了基类的基类的序列化: ar & boost::serialization::base_object<student_info>(*this);void save()
{
std::ofstream ofs("t7.xml");
boost::archive::xml_oarchive oa(ofs);
student_info* sdinfo = new middle_student("wyp", "0099", "1", 15);//#1
oa << BOOST_SERIALIZATION_NVP(sdinfo);//#2
std::cout << "xxxx" << std::endl;
delete sdinfo;
}#1:用一个基类的指针指向了一个用new申请的派生类的指针，很简单，都知道这就是c++的多态。
load的代码：
void load()
{
std::ifstream ifs("t7.xml");
boost::archive::xml_iarchive ia(ifs);
student_info* sdinfo = NULL;//#1
ia >> BOOST_SERIALIZATION_NVP(sdinfo);//#2
middle_student* mds = dynamic_cast<middle_student*>(sdinfo);//#3
mds->print_info();
}#1:基类的指针
测试代码：
void fun()
{
save();
load();
}编译运行！。。。。。。。void save()
{
std::ofstream ofs("t7.xml");
boost::archive::xml_oarchive oa(ofs);
oa.template register_type<middle_student>(NULL);
student_info* sdinfo = new middle_student("wyp", "0099", "1", 15);
oa << BOOST_SERIALIZATION_NVP(sdinfo);
delete sdinfo;
}
void load()
{
std::ifstream ifs("t7.xml");
boost::archive::xml_iarchive ia(ifs);
ia.template register_type<middle_student>(NULL);
student_info* sdinfo = NULL;
ia >> BOOST_SERIALIZATION_NVP(sdinfo);
middle_student* mds = dynamic_cast<middle_student*>(sdinfo);
mds->print_info();
}好这下应改没有异常了吧。
结果编译就出错了！！！
错误在这个函数里面
// Anything not an attribute and not a name-value pair is an
// error and should be trapped here.
template<class T>
void save_override(T & t, BOOST_PFTO int)
{
// If your program fails to compile here, its most likely due to
// not specifying an nvp wrapper around the variable to
// be serialized.
BOOST_MPL_ASSERT((serialization::is_wrapper< T >));
this->detail_common_oarchive::save_override(t, 0);
}看注释就知道了，序列化时存在有些数据没有包装，就是没有用那个宏。
就仔细看一下序列化的代码发现这段代码中有一个没用宏来包装：
private:
friend class boost::serialization::access;
template<typename Archive>
void serialize(Archive& ar, const unsigned int version)
{
ar & boost::serialization::base_object<student_info>(*this);//here!!!!!!!!!!!
ar & BOOST_SERIALIZATION_NVP(age_);
}在调用基类的序列化时没用宏包装
修改如下：
private:
friend class boost::serialization::access;
template<typename Archive>
void serialize(Archive& ar, const unsigned int version)
{
//ar & boost::serialization::base_object<student_info>(*this);
ar & BOOST_SERIALIZATION_BASE_OBJECT_NVP(student_info);
ar & BOOST_SERIALIZATION_NVP(age_);
}编译运行ok！
运行结果如下 t7.xml
<?xml version="1.0" encoding="UTF-8" standalone="yes" ?>
<!DOCTYPE boost_serialization>
<boost_serialization signature="serialization::archive" version="10">
<sdinfo class_id="0" tracking_level="1" version="0" object_id="_0">
<student_info class_id="1" tracking_level="1" version="0" object_id="_1">
<name_>wyp</name_>
<number_>0099</number_>
<grade_>1</grade_>
</student_info>
<age_>15</age_>
</sdinfo>
</boost_serialization>
完整代码如下
#include <fstream>
#include <iostream>
#include <algorithm>
#include <boost/archive/xml_iarchive.hpp>
#include <boost/archive/xml_oarchive.hpp>
#include <boost/serialization/base_object.hpp>
class student_info
{
public:
student_info() {}
virtual ~student_info() {}
student_info(const std::string& sn, const std::string& snm, const std::string& sg)
: name_(sn), number_(snm), grade_(sg)
{
}
virtual void print_info() const
{
std::cout << name_ << " " << number_ << " " << grade_ << std::endl;
}
private:
friend class boost::serialization::access;
template<typename Archive>
void serialize(Archive& ar, const unsigned int version)
{
ar & BOOST_SERIALIZATION_NVP(name_);
ar & BOOST_SERIALIZATION_NVP(number_);
ar & BOOST_SERIALIZATION_NVP(grade_);
}
private:
std::string name_;
std::string number_;
std::string grade_;
};
BOOST_SERIALIZATION_ASSUME_ABSTRACT(student_info)
class middle_student : public student_info
{
public:
middle_student() {}
virtual ~middle_student() {}
middle_student(const std::string& sn, const std::string& snm, const std::string& sg, int age)
: student_info(sn, snm, sg), age_(age)
{
}
virtual void print_info()
{
student_info::print_info();
std::cout << age_ << std::endl;
}
private:
friend class boost::serialization::access;
template<typename Archive>
void serialize(Archive& ar, const unsigned int version)
{
ar & BOOST_SERIALIZATION_BASE_OBJECT_NVP(student_info);
ar & BOOST_SERIALIZATION_NVP(age_);
}
private:
int age_;
};
void save()
{
std::ofstream ofs("t7.xml");
boost::archive::xml_oarchive oa(ofs);
oa.template register_type<middle_student>(NULL);
student_info* sdinfo = new middle_student("wyp", "0099", "1", 15);
oa << BOOST_SERIALIZATION_NVP(sdinfo);
delete sdinfo;
}
void load()
{
std::ifstream ifs("t7.xml");
boost::archive::xml_iarchive ia(ifs);
ia.template register_type<middle_student>(NULL);
student_info* sdinfo = NULL;
ia >> BOOST_SERIALIZATION_NVP(sdinfo);
middle_student* mds = dynamic_cast<middle_student*>(sdinfo);
mds->print_info();
}
void fun()
{
save();
load();
}
boost::serialization 用基类指针转存派生类（错误多多，一波三折）,布布扣,bubuko.com
boost::serialization 用基类指针转存派生类（错误多多，一波三折）
原文地址：http://blog.csdn.net/xiaoliangsky/article/details/24917135
