Managing User Expiration

#include <boost/redis.hpp>
#include <boost/redis/src.hpp>
#include <boost/asio/io_context.hpp>
#include <boost/asio/detached.hpp>
#include <boost/asio/consign.hpp>
#include <nlohmann/json.hpp>
#include <iostream>
#include <memory>

namespace net = boost::asio;
using boost::redis::connection;
using boost::redis::request;
using boost::redis::response;
using boost::redis::config;
using boost::redis::logger;
using json = nlohmann::json;

int main() {
    net::io_context ioc;
    auto conn = std::make_shared<connection>(ioc);

    // Start Redis connection
    conn->async_run(
        config{},
        logger{logger::level::disabled},
        net::consign(net::detached, conn)
    );

    // Create user data as JSON
    json data;
    data["email"] = "user1@example.com";

    // SET user:1 <json> EX 86400 (1 day)
    auto set_req  = std::make_shared<request>();
    auto set_resp = std::make_shared<response<std::string>>();
    set_req->push("SET", "user:1", data.dump(), "EX", "86400");

    conn->async_exec(
        *set_req, *set_resp,
        [conn, set_req, set_resp](boost::system::error_code ec, std::size_t) {
            if (ec) {
                std::cerr << "SET error: " << ec.message() << "\n";
                conn->cancel();
                return;
            }

            // After SET completes, run GET user:1
            auto get_req  = std::make_shared<request>();
            auto get_resp = std::make_shared<response<std::string>>();
            get_req->push("GET", "user:1");

            conn->async_exec(
                *get_req, *get_resp,
                [conn, get_req, get_resp](boost::system::error_code ec, std::size_t) {
                    if (!ec) {
                        auto& res = std::get<0>(*get_resp); // result<std::string, error>
                        if (res) {
                            std::cout << res.value() << std::endl;
                        }
                    } else {
                        std::cerr << "GET error: " << ec.message() << "\n";
                    }
                    conn->cancel();
                }
            );
        }
    );

    ioc.run();
    return 0;
}