C++: What is std::regex?

std::regex — regular expressions library.

1#include <regex>
2
3std::regex email_pattern(R"(\w+@\w+\.\w+)");
4
5std::string text = "Contact: user@example.com";
6std::smatch match;
7
8if (std::regex_search(text, match, email_pattern)) {
9    std::cout << "Found: " << match[0];
10}

Operations:

• regex_search: find match anywhere
• regex_match: match entire string
• regex_replace: replace matches
• sregex_iterator: iterate over all matches

Warning:

• Very slow compared to other regex libraries
• Can be vulnerable to ReDoS
• Consider alternatives (RE2, CTRE)