Archives and serialization in Chrono (demo_CH_archive.cpp)

Tutorial on serialization. Learn how to write serializa C++ classes in various formats:

• JSON
• binary (platform independent)
• ASCII
• etc.

The serialization system in Chrono support class versions, automatic pointer serialization, and other features. Look at the code.

No GUI: only text output.

// =============================================================================
// PROJECT CHRONO - http://projectchrono.org
//
// Copyright (c) 2014 projectchrono.org
// All rights reserved.
//
// Use of this source code is governed by a BSD-style license that can be found
// in the LICENSE file at the top level of the distribution and at
// http://projectchrono.org/license-chrono.txt.
//
// =============================================================================
// Authors: Alessandro Tasora
// =============================================================================
//
// Demo code about
// - archives for serialization,
// - serialization, with versioning and dynamic creation (class factory)
//
// =============================================================================
 
#include <typeinfo>
 
#include "chrono/serialization/ChArchive.h"
#include "chrono/serialization/ChArchiveBinary.h"
#include "chrono/serialization/ChArchiveAsciiDump.h"
#include "chrono/serialization/ChArchiveJSON.h"
#include "chrono/serialization/ChArchiveXML.h"
#include "chrono/serialization/ChArchiveExplorer.h"
 
#include "chrono/core/ChGlobal.h"
 
#include "chrono/core/ChLog.h"
#include "chrono/core/ChVector.h"
#include "chrono/core/ChQuaternion.h"
#include "chrono/core/ChMatrix.h"
#include "chrono/core/ChException.h"
#include "chrono/solver/ChConstraintTuple.h"
 
#include "chrono_thirdparty/filesystem/path.h"
 
using namespace chrono;
 
 
 
enum myEnum {
     ATHLETIC = 0,
     SKINNY = 3,
     FAT
};
 
CH_ENUM_MAPPER_BEGIN(myEnum);
  CH_ENUM_VAL(ATHLETIC);
  CH_ENUM_VAL(SKINNY);
  CH_ENUM_VAL(FAT, "fatty");  // overrides the "FAT" mapped string with "fatty"
CH_ENUM_MAPPER_END(myEnum);
 
 
//
// Define some example classes just for showing how CHRONO serialization
// system works, even with inheritance and versioning...
//
// The statements marked with //##### are mandatory if you want to
// take advantage of basic Chrono streaming and serialization mechanisms,
// that is if you want to save/load the object to&from a stream.
//
// The statements marked with //***** are needed only if you want to
// take advantage of Chrono advanced serialization mechanism, that is the
// polymorphic creation (class factory) which can load an
// object from stream even if the object class is not known in advance.
// This more advanced feature requires a 'class factory' registration
// of your object type by means of the CH_FACTORY_REGISTER macro
//
 
class myEmployee {
 
  public:
    int age;
    double wages;
    myEnum body;
    std::string name;
 
    myEmployee(int m_age = 18, double m_wages = 1020.3, myEnum m_body = myEnum::ATHLETIC, std::string m_name = "John") : 
        age(m_age), 
        wages(m_wages),
        body(m_body),
        name(m_name) {};
 
    virtual ~myEmployee() {}
 
    // MEMBER FUNCTIONS FOR BINARY I/O
    // NOTE!!!In order to allow serialization with Chrono approach,
    // at least implement these two functions, with the exact names
    // ArchiveIN() and ArchiveOUT():
 
    virtual void ArchiveOUT(ChArchiveOut& marchive)  //##### for Chrono serialization
    {
        // suggested: use versioning
        marchive.VersionWrite<myEmployee>();
        // stream out all member data
        marchive << CHNVP(age);
        marchive << CHNVP(wages);
        myEnum_mapper enum_map;
        marchive << CHNVP(enum_map(body), "body"); // note: CHNVP macro can override names used when streaming to ascii..
    }
    virtual void ArchiveIN(ChArchiveIn& marchive)  //##### for Chrono serialization
    {
        // suggested: use versioning
        /*int version =*/ marchive.VersionRead<myEmployee>();
        // stream in all member data
        marchive >> CHNVP(age);
        marchive >> CHNVP(wages);
        myEnum_mapper enum_map;
        marchive >> CHNVP(enum_map(body), "body");
    }
 
    // Optional: implement ArchiveContainerName()  so that, when supported as in JSON, 
    // serialization of containers (std::vector, arrays, etc.) show a mnemonic name 
    // instead of "0", "1", "2", etc. :  
 
    virtual std::string& ArchiveContainerName() {return name;}  //*****  optional, for advanced serialization
};
 
 
// Somewhere in your .cpp code (not in .h headers) you should put the
// 'class factory' registration of your class if you want to deserialize
// objects whose exact class is not known in advance:
 
CH_FACTORY_REGISTER(myEmployee)  //*****  for advanced serialization
 
 
// Ok, now let's do something even more difficult: an inherited class.
 
class myEmployeeBoss : public myEmployee {
 
  public:
    bool is_dumb;
    myEmployee slave;
 
    myEmployeeBoss (const myEmployeeBoss& other) {
        GetLog()<< "------------------copy a boss \n";
    }
 
    myEmployeeBoss(int m_age = 38, double m_wages = 9000.4, bool m_is_dumb = true)
        : myEmployee(m_age, m_wages), 
        is_dumb(m_is_dumb),
        slave(21, 300){};
 
    // MEMBER FUNCTIONS FOR BINARY I/O
 
    virtual void ArchiveOUT(ChArchiveOut& marchive)  //##### for Chrono serialization
    {
        // suggested: use versioning
        marchive.VersionWrite<myEmployeeBoss>();
        // remember to serialize the parent class data too!!!
        myEmployee::ArchiveOUT(marchive);
 
        // stream out member data
        marchive << CHNVP(is_dumb);
        marchive << CHNVP(slave);  // this added only from version >1
    }
    virtual void ArchiveIN(ChArchiveIn& marchive)  //##### for Chrono serialization
    {
        // suggested: use versioning
        int version = marchive.VersionRead<myEmployeeBoss>();
        // remember to deserialize the parent class data too!!!
        myEmployee::ArchiveIN(marchive);
 
        // stream in member data
        marchive >> CHNVP(is_dumb);
        if (version > 1){
            marchive >> CHNVP(slave);  // this added only from version >1
        }
    }
};
 
CH_FACTORY_REGISTER(myEmployeeBoss)  //*****  for advanced serialization
 
// Use the following to mark a class version:   //*****  optional, for advanced serialization
namespace chrono {
CH_CLASS_VERSION(myEmployeeBoss, 2)
}
 
 
// Finally, let's serialize a class that has no default constructor.
// How to manage the (de)serialization of the initialization parameters?
// The trick is adding two optional ArchiveOUTconstructor() and ArchiveINconstructor():
 
class myEmployeeCustomConstructor : public myEmployee {
 
  public:
    double latitude;
    int kids;
    int legs;
 
    myEmployeeCustomConstructor(int m_kids, double m_latitude)
        : myEmployee(80, 4000), 
        latitude(m_latitude),
        kids(m_kids),
        legs (2) {};
 
    // MEMBER FUNCTIONS FOR BINARY I/O
 
    virtual void ArchiveOUT(ChArchiveOut& marchive)  //##### for Chrono serialization
    {
        // suggested: use versioning
        marchive.VersionWrite<myEmployeeCustomConstructor>();
        // remember to serialize the parent class data too!!!
        myEmployee::ArchiveOUT(marchive);
        // stream out member data (except data used in constructor, already saved in ArchiveOUTconstructor)
        marchive << CHNVP(legs);
    }
    virtual void ArchiveIN(ChArchiveIn& marchive)  //##### for Chrono serialization
    {
        // suggested: use versioning
        /*int version =*/ marchive.VersionRead<myEmployeeCustomConstructor>();
        // remember to deserialize the parent class data too!!!
        myEmployee::ArchiveIN(marchive);
        // stream in member data (except data used in constructor, already saved in ArchiveOUTconstructor)
        marchive >> CHNVP(legs);
    }
    
    // Add a  ArchiveOUTconstructor  function to deserialize the parameters 
    // of the non-default constructor!!!
    virtual void ArchiveOUTconstructor(ChArchiveOut& marchive)
    {
        // suggested: use versioning
        marchive.VersionWrite<myEmployeeCustomConstructor>();
 
        // serialize the parameters of the constructor:
        marchive << CHNVP(latitude);
        marchive << CHNVP(kids);
    }
 
    // Add a  ArchiveINconstructor  static function to deserialize the parameters 
    // of the non-default constructor!!!
    static void* ArchiveINconstructor(ChArchiveIn& marchive)
    {
        // suggested: use versioning
        /*int version =*/ marchive.VersionRead<myEmployeeCustomConstructor>();
 
        // 1) Deserialize the parameters of the constructor:
        // you need some auxiliary variables because this method is static 
        // (the object will be created right after the >> parsing)
        // Note, be sure that the names of those auxiliary vars are the same of member 
        // variables of your class, or use  CHNVP(..., "myname") tags.
        double latitude;   
        int    kids;
        marchive >> CHNVP(latitude);
        marchive >> CHNVP(kids);
 
        // 2) Important!!! Finally you MUST return an object of this class, 
        // constructed with the parameters that you just deserialized:
        return new myEmployeeCustomConstructor(kids, latitude);
    }
 
};
 
CH_FACTORY_REGISTER(myEmployeeCustomConstructor)  //*****  for advanced serialization
 
 
                              
 
 
 
//
// Example on how to serialize OUT some data:
//
 
void my_serialization_example(ChArchiveOut& marchive)
{
        // All basic primitives (strings, int,etc.), plus and objects that has
        // an ArchiveOUT() function defined can be serialized in archives.      
 
        // Write from transient data into persistent binary file
        double m_double = 0.123456;
        int m_int = -123;
        double m_array[] = {13.1, 15.3, 16.5};
        char m_text[] = "test string"; // better use std::string
        std::string m_string = "hey! stl string";
        std::vector< double > m_stlvector; 
        m_stlvector.push_back (2.3); 
        m_stlvector.push_back (45.3);
        m_stlvector.push_back (66.44);
        std::list< ChVector<> > m_stllist; 
        m_stllist.push_back ( ChVector<>(1,2,3) ); 
        m_stllist.push_back ( ChVector<>(3,4,5) );
        std::pair<int, double> m_stlpair(120, 0.99);
        std::unordered_map<int, double> m_stlunorderedmap;
        m_stlunorderedmap[12]=11.2;
        m_stlunorderedmap[41]=44.8;
        m_stlunorderedmap[34]=33.6; 
        ChMatrixDynamic<double> m_matr_dyn(3, 5);
        m_matr_dyn.fillRandom(0, 10);
        ChMatrixNM<double,2,3> m_matr_NM;
        m_matr_NM.fillRandom(-1, +1);
        ChVector<> m_vect(0.5, 0.6, 0.7);
        ChQuaternion<> m_quat(0.1, 0.2, 0.3, 0.4);
 
        marchive << CHNVP(m_double,"custom_double");  // store data n.1      
        marchive << CHNVP(m_int);     // store data n.2 
        marchive << CHNVP(m_array);   // store data n.3
        marchive << CHNVP(m_text);    // store data n....
        marchive << CHNVP(m_string);  
        marchive << CHNVP(m_stlvector);
        marchive << CHNVP(m_stllist);
        marchive << CHNVP(m_stlpair);
        marchive << CHNVP(m_stlunorderedmap);
        marchive << CHNVP(m_matr_dyn);
        marchive << CHNVP(m_matr_NM);
        marchive << CHNVP(m_vect);
        marchive << CHNVP(m_quat, "m_quaternion", NVP_TRACK_OBJECT);  
        
        // Also store a c++ object 
        // In order to use this feature, the classes must implement 
        // ArchiveIN and ArchiveOUT functions.
        myEmployeeBoss m_boss(53, 12000.34, true);
        m_boss.body = FAT;
        marchive << CHNVP(m_boss);    
 
        // Also store a c++ objects referenced by pointer(s).
        // One could have multiple pointers to the same object: 
        // the serialization of pointers takes care of redundancy.
        // In order to use this feature, the classes must implement 
        // ArchiveIN and ArchiveOUT functions.
        ChVector<>* a_vect = new ChVector<>(1,2,3); 
        marchive << CHNVP(a_vect);
        delete a_vect;
 
        // Null pointers can be serialized. They will be deserialized as null.
        ChVector<>* a_null_ptr = 0; 
        marchive << CHNVP(a_null_ptr);
 
        // Also store c++ objects referenced by pointer, using the
        // class abstraction (class factory) mechanism, so that it
        // can be loaded later even if we do not know if it was an object of
        // class 'myEmployee' or specialized class 'myEmployeeBoss'...
        // In order to use this feature, classes must use the CH_FACTORY_REGISTER macros, 
        // and must implement ArchiveIN() and ArchiveOUT().
        myEmployeeBoss* a_boss = new myEmployeeBoss(64, 22356, false);
        a_boss->slave.age = 24;
        marchive << CHNVP(a_boss);  //  object was referenced by pointer.
 
        // If another pointer shares the same object instance, you can serialize
        // it too without worrying, because the serialization system will save only
        // the first copy and following copies will just use references.
 
        myEmployeeBoss* a_boss2 = a_boss;
        marchive << CHNVP(a_boss2);  //  object was referenced by pointer.
 
        // Also store c++ objects referenced by shared pointers.
        // If classes of pointed objects used CH_FACTORY_REGISTER, class abstraction
        // will be automatically used.
        auto s_boss = chrono_types::make_shared<myEmployeeBoss>();
        marchive << CHNVP(s_boss);  //  object was referenced by shared pointer.
 
        // Serialize a shared pointer pointing to the same shared resource of s_boss. 
        // Note, base class works fine too, as polymorphic object.
        std::shared_ptr<myEmployee> s_boss_b(s_boss);
        marchive << CHNVP(s_boss_b);
 
        // Serialize null shared pointer
        std::shared_ptr<myEmployeeBoss> null_boss;
        marchive << CHNVP(null_boss); 
 
        // Serialize an object with non-default constructor:
        myEmployeeCustomConstructor* mcustomconstr = new myEmployeeCustomConstructor(3,40);
        marchive << CHNVP(mcustomconstr); 
 
        // Serialize an object where some pointers are un-linked as external, marking them with unique IDs
        std::vector<ChVector<>*> vect_of_pointers;
        ChVector<>* mvp1 = new ChVector<>(1,2,3);
        ChVector<>* mvp2 = new ChVector<>(7,8,7);
        vect_of_pointers.push_back(mvp1);
        vect_of_pointers.push_back(mvp2);
        // define that some object should not be serialized, but rather marked with ID for later rebinding
        marchive.UnbindExternalPointer(mvp1, 1001); // use unique identifier > 0
        marchive << CHNVP(vect_of_pointers);
 
        delete a_boss;
}
 
 
//
// Example on how to deserialize IN some data:
//
 
void my_deserialization_example(ChArchiveIn& marchive)
{  
        // Read from persistent binary file to transient data
        double m_double;
        int m_int;
        double m_array[3];
        char m_text[12]; // better use std::string
        std::string m_string;
        std::vector< double > m_stlvector;
        std::list< ChVector<> > m_stllist;
        std::pair<int, double> m_stlpair;
        std::unordered_map<int, double> m_stlunorderedmap;
        ChMatrixDynamic<> m_matr_dyn;
        ChMatrixNM<double, 2,3> m_matr_NM;
        ChVector<> m_vect;
        ChQuaternion<> m_quat;
        myEmployeeBoss m_boss;
        ChVector<>* a_vect;
        ChVector<>* a_null_ptr;
 
        marchive >> CHNVP(m_double,"custom_double");  // deserialize data n.1
        marchive >> CHNVP(m_int);     // deserialize data n.2
        marchive >> CHNVP(m_array);   // deserialize data n.3
        marchive >> CHNVP(m_text);    // deserialize data n....
        marchive >> CHNVP(m_string);  
        marchive >> CHNVP(m_stlvector);
        marchive >> CHNVP(m_stllist);
        marchive >> CHNVP(m_stlpair);
        marchive >> CHNVP(m_stlunorderedmap);
        marchive >> CHNVP(m_matr_dyn);
        marchive >> CHNVP(m_matr_NM);
        marchive >> CHNVP(m_vect);  
        marchive >> CHNVP(m_quat, "m_quaternion", NVP_TRACK_OBJECT);        
 
        // Also deserialize the C++ object
        marchive >> CHNVP(m_boss); 
 
        // Also deserialize the C++ pointer: an object will be created!
        marchive >> CHNVP(a_vect); 
 
        // Also deserialize the null C++ pointer: no object is created, and pointer set as null.
        marchive >> CHNVP(a_null_ptr);
 
        // Also retrieve c++ objects, referenced by a base class pointer, using the
        // class abstraction (class factory) mechanism, so that it
        // can be loaded even if we do not know if it was an object of
        // the base class 'myEmployee' or the specialized 'myEmployeeBoss' class..
        myEmployee* a_boss = 0;
        marchive >> CHNVP(a_boss);  // object will be created
 
        // Since the two pointers a_boss and a_boss2 were serialized when pointing to 
        // the same object instance, now the following will Not create another copy but will
        // automatically point to the same object of a_boss. 
        myEmployee* a_boss2 = 0;
        marchive >> CHNVP(a_boss2); 
 
 
        // Deserialize c++ objects referenced by shared pointers.
        // If classes of pointed objects used CH_FACTORY_REGISTER, class abstraction
        // will be automatically used.
        std::shared_ptr<myEmployeeBoss> s_boss(0);
        marchive >> CHNVP(s_boss);
 
        // Deserialize a shared pointer pointing to the same resource of s_boss.
        // Since the two pointers s_boss and s_boss_b were serialized when pointing to 
        // the same object instance, do not create new, but just point to the same of s_boss. 
        // Also, the shared pointer reference count is increased automatically.
        std::shared_ptr<myEmployeeBoss> s_boss_b(0);
        marchive >> CHNVP(s_boss_b);
 
        // Deserialize a null shared pointer
        std::shared_ptr<myEmployeeBoss> null_boss(0);
        marchive >> CHNVP(null_boss);
 
        // Deserialize an object with non-default constructor:
        myEmployeeCustomConstructor* mcustomconstr = 0;
        marchive >> CHNVP(mcustomconstr); 
 
        // Deserialize an object where some pointers are re-linked from external pre-existing objects,
        // marking them with unique IDs. Assume a ChVector is already here. 
        std::vector<ChVector<>*> vect_of_pointers;
        ChVector<>* mvp1 = new ChVector<>(5,6,7);
        marchive.RebindExternalPointer(mvp1, 1001); // use unique identifier > 0
        marchive >> CHNVP(vect_of_pointers);
 
 
 
        // Just for safety, log some of the restored data:
 
        GetLog() << "\n\nSome results of deserialization I/O: \n\n" << m_text << " \n" << m_int << " \n" << m_double << "\n";
        GetLog() << m_matr_NM;
        GetLog() << m_vect;
        GetLog() << m_quat;
        GetLog() << m_string.c_str() << "\n";
        GetLog() << m_stlvector;
        GetLog() << m_stlpair;
        GetLog() << m_stlunorderedmap;
        GetLog() << m_boss;
        GetLog() << a_vect;
 
        if (a_boss) {
            GetLog() << "\n\n We loaded an obj inherited from myEmployee class:\n";
            GetLog() << a_boss;
        }
        if (a_boss2) {
            GetLog() << "\n\n We loaded a 2nd obj inherited from myEmployee class (referencing the 1st):\n";
            GetLog() << a_boss2;
        }
        if (s_boss) {
            GetLog() << "\n\n We loaded a 3nd obj inherited from myEmployee class:\n";
            GetLog() << s_boss;
            GetLog() << "(This object is handled by shared pointers, with ref.count=" << (int)s_boss.use_count() << ")\n";
        }
        if (!null_boss) {
            GetLog() << "\n\n We tried to load a 4th obj with shared pointer, but was null.\n";
        }
        if (mcustomconstr) {
            GetLog() << "\n\n We loaded a 5th object with non-default constructor with 2 parameters.\n";
            GetLog() << mcustomconstr;
        }
        GetLog() << "\n\n We loaded a 6th object where sub-objects were unbind/rebind using IDs:\n";
        GetLog() << vect_of_pointers;
        GetLog() << *vect_of_pointers[0];
        GetLog() << *vect_of_pointers[1];
 
 
        GetLog() << "\n";
        GetLog() << "loaded object is a myEmployee?     :" << (dynamic_cast<myEmployee*>(a_boss) !=nullptr) << "\n";
        GetLog() << "loaded object is a myEmployeeBoss? :" << (dynamic_cast<myEmployeeBoss*>(a_boss) !=nullptr) << "\n";
 
        delete a_boss;
}
 
 
//
// Example on how to use reflection (c++ introspection) to explore the properties exposed 
// through the ArchiveIN() and ArchiveOUT() functions.
//
 
void my_reflection_example()
{
    ChArchiveExplorer mexplorer;
    mexplorer.SetUseWildcards(true);
    mexplorer.SetUseUserNames(true);
 
    myEmployeeBoss m_boss(71, 42000.4, true);
    m_boss.body = FAT;
 
    double my_wages;
    if (mexplorer.FetchValue(my_wages, m_boss, "wages"))
        GetLog() << "Property explorer : retrieved 'wages'=" << my_wages << "\n";
    else
        GetLog() << "Property explorer : cannot retrieve 'wages'! \n";
 
    myEmployee my_slave;
    if (mexplorer.FetchValue(my_slave, m_boss, "slave"))
        GetLog() << "Property explorer : retrieved 'slave'=\n" << my_slave << "\n";
    else
        GetLog() << "Property explorer : cannot retrieve 'slave'! \n";
 
    int my_age;
    if (mexplorer.FetchValue(my_age, m_boss, "s?*e/age"))
        GetLog() << "Property explorer : retrieved 'slave/age'=" << my_age << "\n";
    else
        GetLog() << "Property explorer : cannot retrieve 'slave/age'! \n";
 
    int my_foo = 123;
    if (mexplorer.FetchValue(my_foo, m_boss, "foo"))
        GetLog() << "Property explorer : retrieved 'int foo'=" << my_foo << "\n";
    else
        GetLog() << "Property explorer : cannot retrieve 'int foo'! \n";
 
    // Test access to containers (std::vector, arrays, etc.). Elements can
    // be fetched using two approaches: integer indexes or menmonic names.
    std::vector<myEmployee> mcontainer;
    mcontainer.push_back(myEmployee(19,4000,ATHLETIC, "Josh"));
    mcontainer.push_back(myEmployeeBoss(29,5000, "Jeff"));
    mcontainer.push_back(myEmployee(31,6000,ATHLETIC, "Marie"));
    myEmployee a_employee;
 
    // Method A: just use the index in the search string, 
    //   ex: "stuff/arrayofpositions/6/x" as in:
 
    if (mexplorer.FetchValue(a_employee, mcontainer, "1"))
        GetLog() << "Property explorer : retrieved from element number in container '1' =\n" << a_employee << "\n";
    else
        GetLog() << "Property explorer : cannot retrieve from element number! \n";
 
    // Method B: if you deal if working with objects that implement 
    // ArchiveContainerName(), you can use the name between single quotation marks '...',
    //   ex: "stuff/arrayofbodies/'Crank'/mass" as in:
    if (mexplorer.FetchValue(a_employee, mcontainer, "'Marie'"))
        GetLog() << "Property explorer : retrieved from element container name 'Marie' =\n" << a_employee << "\n";
    else
        GetLog() << "Property explorer : cannot retrieve from element container name! \n";
 
    // Test if some object can be explored
    GetLog() << "This has sub properties? : " << mexplorer.IsObject(mcontainer) << "\n";
    GetLog() << "This has sub properties? : " << mexplorer.IsObject(my_age) << "\n\n";
 
    // Fetch all subproperties of an object using "*"
    GetLog() << "List of fetched properties in std::vector of employees: \n";
    auto props = mexplorer.FetchValues(mcontainer, "*");
    for (auto i : props) {
        GetLog() << " val: " << i->name() << ",  reg.class: " << i->GetClassRegisteredName() << ",  typeid: " << i->GetTypeidName() << "\n";
        //if (auto pi = dynamic_cast<myEmployeeBoss*>(i->PointerUpCast<myEmployee>()))
        //    GetLog() <<"   castable to myEmployeeBoss \n";
        ChArchiveExplorer mexplorer2;
        auto props2 = mexplorer2.FetchValues(*i, "*");
        for (auto i2 : props2) {
            GetLog() << "    val: " << i2->name() << ",  reg.class: " << i2->GetClassRegisteredName() << ",  typeid: " << i2->GetTypeidName() << "\n";
        }
    }
}
 
 
 
int main(int argc, char* argv[]) {
    GetLog() << "Copyright (c) 2017 projectchrono.org\nChrono version: " << CHRONO_VERSION << "\n\n";
 
    GetLog() << "CHRONO foundation classes demo: archives (serialization)\n\n";
 
    // Create (if needed) output directory
    const std::string out_dir = GetChronoOutputPath() + "DEMO_ARCHIVE";
    if (!filesystem::create_directory(filesystem::path(out_dir))) {
        std::cout << "Error creating directory " << out_dir << std::endl;
        return 1;
    }
 
    //  Archives inherited from the base class ChArchiveOut can be
    // used to serialize objects, and streams inherited from ChArchiveIn
    // can be used to get them back. For example, file streams like
    // ChArchiveOutBinary and ChArchiveInBinary can be used for this
    // purpose.
    
    try {       
        
        
        {
            //
            // Example: SERIALIZE TO ASCII DUMP (useful for debugging etc.):
            //
 
            std::string asciifile = out_dir + "/foo_archive.txt";
            ChStreamOutAsciiFile mfileo(asciifile.c_str());
 
            // Create an ASCII archive object, for dumping C++ objects into a readable file
            ChArchiveAsciiDump marchiveout(mfileo);
        
            my_serialization_example(marchiveout);
        }
 
 
        {
            //
            // Example: SERIALIZE TO/FROM BINARY:
            //
 
            {
                std::string binfile = out_dir + "/foo_archive.dat";
                ChStreamOutBinaryFile mfileo(binfile.c_str());
                
                // Use a binary archive object to serialize C++ objects into the binary file
                ChArchiveOutBinary marchiveout(mfileo);
 
                my_serialization_example(marchiveout);
            }
 
            {
                std::string binfile = out_dir + "/foo_archive.dat";
                ChStreamInBinaryFile mfilei(binfile.c_str());
                
                // Use a binary archive object to deserialize C++ objects from the binary file
                ChArchiveInBinary marchivein(mfilei);
 
                my_deserialization_example(marchivein);
            }
        }
 
 
        {
            //
            // Example: SERIALIZE TO/FROM JSON:
            //
 
            {
                std::string jsonfile = out_dir + "/foo_archive.json";
                ChStreamOutAsciiFile mfileo(jsonfile.c_str());
 
                // Use a JSON archive object to serialize C++ objects into the file
                ChArchiveOutJSON marchiveout(mfileo);
        
                my_serialization_example(marchiveout);
            }
 
            
            {
                std::string jsonfile = out_dir + "/foo_archive.json";
                ChStreamInAsciiFile mfilei(jsonfile.c_str());
 
                // Use a JSON archive object to deserialize C++ objects from the file
                ChArchiveInJSON marchivein(mfilei);
 
                my_deserialization_example(marchivein);
            }
            
        }
 
 
        {
            //
            // Example: SERIALIZE TO/FROM XML
            //
            {
                std::string xmlfile = out_dir + "/foo_archive.xml";
                ChStreamOutAsciiFile mfileo(xmlfile.c_str());
 
                // Use a XML archive object to serialize C++ objects into the file
                ChArchiveOutXML marchiveout(mfileo);
 
                my_serialization_example(marchiveout);
            }
 
            {
                std::string xmlfile = out_dir + "/foo_archive.xml";
                ChStreamInAsciiFile mfilei(xmlfile.c_str());
 
                // Use a XML archive object to deserialize C++ objects from the file
                ChArchiveInXML marchivein(mfilei);
 
                my_deserialization_example(marchivein);
            }
 
        }
 
 
        GetLog() << "Serialization test ended with success.\n\n";
 
 
        my_reflection_example();
 
        GetLog() << "Reflection test ended with success.\n";
 
 
        
 
    } catch (const ChException &myex) {
        GetLog() << "ERROR: " << myex.what() << "\n\n";
    }
 
 
    return 0;
}