Serialization of Objects in C++: Libraries and Methods

Serialization of Objects in C++: Overview of Tools and Libraries

Serialization is the process of converting complex data structures (objects, arrays, graphs) into a linear format (byte stream, JSON string, XML) that can be saved to a file, transmitted over a network, or written to a database. The reverse process — deserialization — restores the original state of the object. C++ has no built-in support for reflection (as in Java or Python), so for serialization you either have to write code manually or use ready-made libraries. In this article, we will cover the most popular and effective tools for serialization in C++.

1. Boost.Serialization

The oldest and most powerful library. It is part of Boost and requires separate installation. Supports binary, textual (XML), and its own portable archive formats.

• Advantages: deep support for STL, smart pointers, polymorphism, cyclic references; versioning; cross-platform compatibility.
• Disadvantages: verbose syntax, slow compilation, large executable size.

#include <boost/archive/text_oarchive.hpp>#include <boost/archive/text_iarchive.hpp>#include <boost/serialization/vector.hpp>#include <fstream>#include <vector>

struct Person {    std::string name;    int age;    std::vector<std::string> tags;

    template<class Archive>    void serialize(Archive & ar, const unsigned int version) {        ar & name;        ar & age;        ar & tags;    }};

int main() {    Person p{"Alice", 30, {"developer", "cpp"}};    std::ofstream ofs("person.txt");    boost::archive::text_oarchive oa(ofs);    oa << p;

    // Deserialization    Person restored;    std::ifstream ifs("person.txt");    boost::archive::text_iarchive ia(ifs);    ia >> restored;    return 0;}

2. Cereal

A modern, lightweight, header-only library (no build required). Works with C++11 and above. Supports JSON, XML, and binary formats. Very popular in the game industry and embedded development.

• Advantages: minimal overhead, intuitive API, support for smart pointers, polymorphism, STL containers.
• Disadvantages: fewer customization options compared to Boost.

#include <cereal/archives/json.hpp>#include <cereal/types/vector.hpp>#include <cereal/types/string.hpp>#include <sstream>

struct Person {    std::string name;    int age;

    template<class Archive>    void serialize(Archive & ar) {        ar(CEREAL_NVP(name), CEREAL_NVP(age));    }};

int main() {    Person p{"Bob", 25};    std::ostringstream oss;    {        cereal::JSONOutputArchive archive(oss);        archive(CEREAL_NVP(p));    }    std::cout << oss.str() << std::endl;

    // Deserialization    Person restored;    std::istringstream iss(oss.str());    {        cereal::JSONInputArchive archive(iss);        archive(restored);    }    return 0;}

3. nlohmann/json (JSON for Modern C++)

The most popular library for working with JSON in C++. Although not originally designed for object serialization, it can be easily adapted using custom converters (adapter pattern).

• Advantages: simple and elegant syntax, excellent documentation, header-only, integration with any types.
• Disadvantages: works only with JSON, does not support binary formats, requires manual description for complex object graphs.

#include <nlohmann/json.hpp>#include <fstream>

using json = nlohmann::json;

struct Point {    double x, y;