serde_struct.cpp

struct X {
    unsigned int length;
    char *str;
};

std::string serialize(const X &x) {
    std::string s;
    s.resize(sizeof(x.length) + x.length);
    std::memcpy(s.c_str(), &x.length, sizeof(x.length));
    std::memcpy(s.c_str() + sizeof(x.length), x.str, x.length);
    return s;
}

X deserialize(const std::string &s) {
    X x;
    std::memcpy(&x.length, s.c_str(), sizeof(x.length));
    x.str = new char[x.length];
    std::memcpy(x.str, s.c_str() + sizeof(x.length), x.length);
    return x;
}