std::match_results<BidirIt,Alloc>::size (3) - Linux Manuals

std::match_results<BidirIt,Alloc>::size: std::match_results<BidirIt,Alloc>::size

NAME

std::match_results<BidirIt,Alloc>::size - std::match_results<BidirIt,Alloc>::size

Synopsis

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.

Parameters

(none)

Return value

The number of submatches

Complexity

Constant

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