std::match_results<BidirIt,Alloc>::size
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(until C++20)
size_type size() const noexcept;
(since C++11)
Returns the number of submatches, i.e. std::distance (begin(), end()).
Returns 0 if *this does not represent the result of a successful match.
[edit] Parameters
(none)
[edit] Return value
The number of submatches.
[edit] Complexity
Constant.
[edit] Example
Run this code
#include <iostream> #include <regex> #include <string> int main() { std::regex re("a(a)*b"); std::string target("aaab"); std::smatch sm; std::cout << sm.size() << '\n'; std::regex_match (target, sm, re); std::cout << sm.size() << '\n'; }
Output:
0 2