std::sub_match::length - cppreference.com (original) (raw)

| difference_type length() const; | | | | -------------------------------- | | |

Returns the number of characters in the match.

[edit] Return value

std::distance(first, second) if the match is valid, ​0​ otherwise.

[edit] Complexity

Constant.

[edit] Example

#include #include #include   int main() { std::string sentence{"Quick red fox jumped over a lazy cow."}; const std::regex re{"([A-z]+) ([a-z]+) ([a-z]+) ([a-z]+)"}; std::smatch words; std::regex_search(sentence, words, re); for (const auto& m : words) std::cout << '[' << m << "], length = " << m.length() << '\n'; }

Output:

[Quick red fox jumped], length = 20 [Quick], length = 5 [red], length = 3 [fox], length = 3 [jumped], length = 6