std::match_results<BidirIt,Alloc>::prefix (3) - Linux Man Pages

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

NAME

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

Synopsis


const_reference prefix() const; (since C++11)


Obtains a reference to the std::sub_match object representing the target sequence between the start of the beginning of the target sequence and the start of the entire match of the regular expression.
The behavior is undefined unless ready() == true

Parameters


(none)

Return value


Reference to the unmatched prefix.

Example


// Run this code


  #include <iostream>
  #include <regex>
  #include <string>


  int main()
  {
    std::regex re("a(a)*b");
    std::string target("baaaby");
    std::smatch sm;


    std::regex_search(target, sm, re);
    std::cout << sm.prefix().str() << '\n';
  }

Output:


  b