[C++]ylt/struct_pack

hello-ylt-struct_pack.cpp

// struct_pack : https://alibaba.github.io/yalantinglibs/en/struct_pack/struct_pack_intro.html
#include <iostream>
#include <sstream>
#include <vector>
#include <map>
#include <ylt/struct_pack.hpp>

struct person
{
    int64_t                    id;
    std::string                name;
    int                        age;
    double                     salary;
    std::vector<int>           primes;
    std::map<int, std::string> numberStrings;

    void print(std::stringstream &out, const std::string &prefix) const {
        out << prefix << ".id = " << id << "\n";
        out << prefix << ".name = " << name << "\n";
        out << prefix << ".age = " << age << "\n";
        out << prefix << ".salary = " << salary << "\n";
        out << prefix << ".primes.size = " << primes.size() << "\n";

        out << prefix << "primes";
        out << "[" << primes.size() << "] = {";
        for (const auto &i : primes) {
            out << " " << i << ", ";
        }
        out << "}\n";

        out << prefix << "numberStrings";
        out << "[" << numberStrings.size() << "] = {\n";
        for (const auto &kv : numberStrings) {
            out << prefix << "  { " << kv.first << ", " << kv.second << " }\n";
        }
        out << prefix << "}\n";
    }
};

int main() {
    // source
    const person src_person{
        .id = 1, .name = "hello struct_pack", .age = 20, .salary = 1024.42, .primes = { 2, 3, 5, 7, 11, 13, 17, 19 },
        .numberStrings = {
            { 1, "one" },
            { 2, "two" },
            { 3, "three" },
        },
    };

    // prepare serialization
    const auto            sp_size = struct_pack::get_needed_size(src_person);
    const std::unique_ptr memory  = std::make_unique<char[]>(sp_size.size());
    const std::span<char> buf(memory.get(), sp_size.size());

    // serialize
    struct_pack::serialize_to(buf.data(), sp_size, src_person);

    // deserialize
    person     des_person;
    const auto error_code = struct_pack::deserialize_to(des_person, buf.data(), buf.size());

    // check
    bool ok = false;
    if (error_code) {
        std::cout << "error_code = " << error_code.val() << " (" << error_code.message() << ")\n";
    } else {
        std::stringstream out1;
        src_person.print(out1, "  ");

        std::stringstream out2;
        des_person.print(out2, "  ");

        std::cout << "src_person\n" << out1.str() << "\n";
        std::cout << "des_person\n" << out2.str() << "\n";

        ok = (out1.str() == out2.str());
    }

    if (ok) {
        std::cout << "OK\n";
    } else {
        std::cout << "*** !!! ERROR !!! ***\n";
    }

    return ok ? EXIT_SUCCESS : EXIT_FAILURE;
}