Is it possible to serialize and deserialize a class in C++?

Question

Is it possible to serialize and deserialize a class in C++?

I\'ve been using Java for 3 years now, and serialization / deserialization is fairly trivial in that lang

Answer 1

Here is a simple serializer library I knocked up. It's header only, c11 and has examples for serializing basic types. Here's one for a map to class.

https://github.com/goblinhack/simple-c-plus-plus-serializer

#include "c_plus_plus_serializer.h"

class Custom {
public:
    int a;
    std::string b;
    std::vector c;

    friend std::ostream& operator<<(std::ostream &out, 
                                    Bits my)
    {
        out << bits(my.t.a) << bits(my.t.b) << bits(my.t.c);
        return (out);
    }

    friend std::istream& operator>>(std::istream &in, 
                                    Bits my)
    {
        in >> bits(my.t.a) >> bits(my.t.b) >> bits(my.t.c);
        return (in);
    }

    friend std::ostream& operator<<(std::ostream &out, 
                                    class Custom &my)
    {
        out << "a:" << my.a << " b:" << my.b;

        out << " c:[" << my.c.size() << " elems]:";
        for (auto v : my.c) {
            out << v << " ";
        }
        out << std::endl;

        return (out);
    }
};

static void save_map_key_string_value_custom (const std::string filename)
{
    std::cout << "save to " << filename << std::endl;
    std::ofstream out(filename, std::ios::binary );

    std::map< std::string, class Custom > m;

    auto c1 = Custom();
    c1.a = 1;
    c1.b = "hello";
    std::initializer_list L1 = {"vec-elem1", "vec-elem2"};
    std::vector l1(L1);
    c1.c = l1;

    auto c2 = Custom();
    c2.a = 2;
    c2.b = "there";
    std::initializer_list L2 = {"vec-elem3", "vec-elem4"};
    std::vector l2(L2);
    c2.c = l2;

    m.insert(std::make_pair(std::string("key1"), c1));
    m.insert(std::make_pair(std::string("key2"), c2));

    out << bits(m);
}

static void load_map_key_string_value_custom (const std::string filename)
{
    std::cout << "read from " << filename << std::endl;
    std::ifstream in(filename);

    std::map< std::string, class Custom > m;

    in >> bits(m);
    std::cout << std::endl;

    std::cout << "m = " << m.size() << " list-elems { " << std::endl;
    for (auto i : m) {
        std::cout << "    [" << i.first << "] = " << i.second;
    }
    std::cout << "}" << std::endl;
}

void map_custom_class_example (void)
{
    std::cout << "map key string, value class" << std::endl;
    std::cout << "============================" << std::endl;
    save_map_key_string_value_custom(std::string("map_of_custom_class.bin"));
    load_map_key_string_value_custom(std::string("map_of_custom_class.bin"));
    std::cout << std::endl;
}

Output:

map key string, value class
============================
save to map_of_custom_class.bin
read from map_of_custom_class.bin

m = 2 list-elems {
    [key1] = a:1 b:hello c:[2 elems]:vec-elem1 vec-elem2
    [key2] = a:2 b:there c:[2 elems]:vec-elem3 vec-elem4
}