Generate Random Phone Numbers in C++

#include <iostream>
#include <random>
#include <sstream>
#include <iomanip>
#include <vector>
#include <regex>

class PhoneNumberGenerator {
private:
    std::mt19937 rng;
    std::uniform_int_distribution<int> areaCodeDist;
    std::uniform_int_distribution<int> exchangeDist;
    std::uniform_int_distribution<int> lineNumberDist;
    std::uniform_int_distribution<int> digitDist;

public:
    PhoneNumberGenerator()
        : rng(std::random_device{}()),
          areaCodeDist(200, 999),
          exchangeDist(200, 999),
          lineNumberDist(1000, 9999),
          digitDist(0, 9) {}

    // Generate random US phone number (xxx) xxx-xxxx
    std::string randomUsPhoneNumber() {
        std::ostringstream oss;
        oss << "(" << std::setw(3) << std::setfill('0') << areaCodeDist(rng) << ") "
            << std::setw(3) << std::setfill('0') << exchangeDist(rng) << "-"
            << std::setw(4) << std::setfill('0') << lineNumberDist(rng);
        return oss.str();
    }

    // Generate random phone number with country code
    std::string randomInternationalPhone(const std::string& countryCode = "+1") {
        std::ostringstream oss;
        oss << countryCode << " (" << std::setw(3) << std::setfill('0') << areaCodeDist(rng) << ") "
            << std::setw(3) << std::setfill('0') << exchangeDist(rng) << "-"
            << std::setw(4) << std::setfill('0') << lineNumberDist(rng);
        return oss.str();
    }

    // Generate phone number without formatting
    std::string randomPhoneDigits(int length = 10) {
        std::ostringstream oss;
        for (int i = 0; i < length; ++i) {
            oss << digitDist(rng);
        }
        return oss.str();
    }

    // Validate US phone number format
    bool isValidUsPhone(const std::string& phone) {
        std::regex pattern(R"(^\(\d{3}\) \d{3}-\d{4}$)");
        return std::regex_match(phone, pattern);
    }

    // Generate multiple phone numbers
    std::vector<std::string> generatePhoneNumbers(int count = 10) {
        std::vector<std::string> phones;
        phones.reserve(count);
        for (int i = 0; i < count; ++i) {
            phones.push_back(randomUsPhoneNumber());
        }
        return phones;
    }
};

int main() {
    PhoneNumberGenerator generator;

    std::cout << "US Phone: " << generator.randomUsPhoneNumber() << std::endl;
    std::cout << "International: " << generator.randomInternationalPhone("+44") << std::endl;
    std::cout << "Digits only: " << generator.randomPhoneDigits(10) << std::endl;
    std::cout << "Valid: " << (generator.isValidUsPhone("(555) 123-4567") ? "true" : "false") << std::endl;

    auto batch = generator.generatePhoneNumbers(3);
    std::cout << "Batch: ";
    for (size_t i = 0; i < batch.size(); ++i) {
        std::cout << batch[i];
        if (i < batch.size() - 1) std::cout << ", ";
    }
    std::cout << std::endl;

    return 0;
}