std::sub_match<BidirIt>::length
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std::sub_match
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sub_match::length
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(until C++20)(until C++20)(until C++20)(until C++20)(until C++20)(C++20)
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
Run this code
#include <iostream> #include <regex> #include <string> 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