Trimming string in C++

trim.cpp

#include <string>
#include <iostream>

//
//Left trim
//
std::string trim_left(const std::string& str)
{
  const std::string pattern = " \f\n\r\t\v";
  return str.substr(str.find_first_not_of(pattern));
}

//
//Right trim
//
std::string trim_right(const std::string& str)
{
  const std::string pattern = " \f\n\r\t\v";
  return str.substr(0,str.find_last_not_of(pattern) + 1);
}

//
//Left and Right trim
//
std::string trim(const std::string& str)
{
  return trim_left(trim_right(str));
}


//
// How to use:
//
int main(int argc, char **argv)
{
    
  std::string source 		= "  Parangari kutiri miruaro  ";
  std::string str_trim_left 	= trim_left(source);
  std::string str_trim_right 	= trim_right(source);
  std::string str_trim_all 	= trim(source);
  
  std::cout << "\"" << source 		<< "\""	<< std::endl;
  std::cout << "\"" << str_trim_left 	<< "\"" << std::endl;
  std::cout << "\"" << str_trim_right 	<< "\"" << std::endl;
  std::cout << "\"" << str_trim_all 	<< "\"" << std::endl;
  
  return 0;
  
}