std::match_results::size

From cppreference.com
size_type size() const;
(since C++11)

Returns the number of submatches, i.e. std::distance(begin(), end()).

Contents

[edit] Parameters

(none)

[edit] Return value

The number of submatches

[edit] Exceptions

noexcept specification:  
noexcept
  (since C++11)

[edit] Complexity

Constant

[edit] See also

[edit] Example

#include <iostream>
#include <regex>
#include <string>
 
int main()
{
    std::regex re("a(a)*b");
    std::string target("aaab");
    std::smatch sm;
 
    std::regex_match(target, sm, re);
    std::cout << sm.size() << '\n';
}

Output:

2