#include <iostream>
#include <string>
#include <regex>

int main() {
    std::string text = "Hello, World!";
    std::regex pattern("^[a-zA-Z]+, [a-zA-Z]+!$");

    if (std::regex_match(text, pattern)) {
        std::cout << "The string matches the pattern." << std::endl;
    } else {
        std::cout << "The string does not match the pattern." << std::endl;
    }

    return 0;
}

The string matches the pattern.

#include <iostream>
#include <string>
#include <regex>

int main() {
    std::string text = "123-456-7890 and 987-654-3210";
    std::regex pattern("\d{3}-\d{3}-\d{4}");

    std::smatch matches;
    while (std::regex_search(text, matches, pattern)) {
        std::cout << "Found: " << matches[0] << std::endl;
        text = matches.suffix().str();
    }

    return 0;
}

Found: 123-456-7890
Found: 987-654-3210

#include <iostream>
#include <string>
#include <regex>

int main() {
    std::string text = "Hello, World!";
    std::regex pattern("World");
    std::string replacement = "Universe";

    std::string result = std::regex_replace(text, pattern, replacement);

    std::cout << "Original: " << text << std::endl;
    std::cout << "Modified: " << result << std::endl;

    return 0;
}

Original: Hello, World!
Modified: Hello, Universe!