C++ Handbook

Header Reference: <regex>

Header Reference: <regex>

Regular expression types, match results, iterators, and algorithms provided by <regex>.

How to use this reference page

Use reference pages to confirm names, categories, nearby facilities, and the constraints that matter before writing or reviewing code.

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  • Use the nearby-page links when your question is really about a companion header, related algorithm family, or broader subsystem.
  • Validate tricky behavior with a small compileable example before relying on memory for details like invalidation, ordering, allocation, or lifetime rules.

What header pages are for

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  • Start here when you already know roughly which header you need but want a fast operational summary.
  • Use the example section below as a minimal pattern, then adapt it to your real container, ownership, text, or concurrency workflow.
  • Jump to broader index pages when you need exhaustive coverage rather than a header-focused summary.

Header Reference: <regex>

Main facilities

What this header is for

Use <regex> when you need declarative pattern matching over strings and character ranges.

Common patterns

Notes

Minimal example

#include <regex>
#include <string>

int main() {
    std::regex pattern{"[a-z]+"};
    return std::regex_match(std::string{"token"}, pattern) ? 0 : 1;
}

What to verify before relying on this header

  • Whether the code needs ownership, borrowing, locale awareness, or low-allocation conversion behavior.
  • How errors are reported: stream state, parse result, exception, error code, or boolean match result.
  • Whether encoding, formatting, or lifetime assumptions need to be made explicit in the surrounding API.