main.cpp

#include <iostream>
#include <fstream>
#include <vector>
#include <iomanip>
#include <boost/iostreams/device/mapped_file.hpp>
#include <boost/iostreams/device/array.hpp>
#include <boost/iostreams/stream.hpp>
#include <boost/archive/binary_iarchive.hpp>
#include <boost/archive/binary_oarchive.hpp>
#include <boost/serialization/vector.hpp>
#include <boost/interprocess/file_mapping.hpp>
#include <boost/interprocess/shared_memory_object.hpp>
#include <boost/interprocess/mapped_region.hpp>
#include <boost/interprocess/streams/bufferstream.hpp>



int main(int argc, char* argv[]) {
    using namespace std;
    using namespace boost::interprocess;
    using namespace std::string_literals;

    std::string path = "Boost";
    //00000000: 0300 0000 0000 0000 4654 5733 3333 3333  ........FTW33333
    //00000010: 3333                                     33

    std::string data1 = "FTW";
    auto read = [](void *out, size_t size) -> size_t {
        memset(out, 0x33, size);
        return size;
    };

    std::ofstream os(path, std::ios_base::binary|std::ios_base::out);
    boost::archive::binary_oarchive arch(os, boost::archive::no_header);

    arch<<data1;

    std::vector<char> data2;
    data2.reserve(7);
    read(&data2[0], 7);
    os.write(&data2[0], 7);

    return 0;
}