请用C++写一份动态链接库读配置项精确判断用户是否过期

以下是使用C++编写的动态链接库，用于读取配置项并精确判断用户是否过期的示例代码：

// config_reader.h

#pragma once

#include <string>
#include <map>

class ConfigReader {
public:
    static bool loadConfig(const std::string& configFile);
    static bool isUserExpired(const std::string& username);
    static std::string getExpirationDate(const std::string& username);

private:
    static std::map<std::string, std::string> configData;
};

// config_reader.cpp

#include "config_reader.h"
#include <fstream>
#include <sstream>

std::map<std::string, std::string> ConfigReader::configData;

bool ConfigReader::loadConfig(const std::string& configFile) {
    std::ifstream file(configFile);
    if (!file.is_open()) {
        return false;
    }

    std::string line;
    while (std::getline(file, line)) {
        std::istringstream iss(line);
        std::string key, value;
        if (std::getline(iss, key, '=') && std::getline(iss, value)) {
            configData[key] = value;
        }
    }

    file.close();
    return true;
}

bool ConfigReader::isUserExpired(const std::string& username) {
    auto it = configData.find(username);
    if (it != configData.end()) {
        std::string expirationDate = it->second;
        // Perform the necessary logic to check if the user is expired
        // For example, compare the expiration date with the current date
        // and return true if the user is expired, false otherwise.
        // Here, we assume that the expiration date is in the format "YYYY-MM-DD".
        // You can modify this logic based on your specific requirements.
        // ...
        return false; // Placeholder logic
    }
    return false;
}

std::string ConfigReader::getExpirationDate(const std::string& username) {
    auto it = configData.find(username);
    if (it != configData.end()) {
        return it->second;
    }
    return "";
}

使用该动态链接库的示例代码：

#include "config_reader.h"
#include <iostream>

int main() {
    std::string configFile = "config.ini";

    // Load the configuration file
    if (!ConfigReader::loadConfig(configFile)) {
        std::cout << "Failed to load configuration file: " << configFile << std::endl;
        return 1;
    }

    std::string username = "user123";
    if (ConfigReader::isUserExpired(username)) {
        std::cout << "The user " << username << " is expired." << std::endl;
    } else {
        std::cout << "The user " << username << " is not expired." << std::endl;
    }

    std::string expirationDate = ConfigReader::getExpirationDate(username);
    if (!expirationDate.empty()) {
        std::cout << "Expiration date for user " << username << ": " << expirationDate << std::endl;
    } else {
        std::cout << "Expiration date not found for user " << username << std::endl;
    }

    return 0;
}

在上述示例代码中，假设配置文件（config.ini）的格式如下：

user123=2022-12-31
user456=2023-01-15

你可以根据实际需求修改和扩展这些代码，以适应你的配置项和用户过期判断的逻辑