Trim a string

trim_string.cpp

void trim( std::string& str, const std::string& whitespaces=" \t\f\v\n\r" )
{
  size_t found = str.find_first_not_of( whitespaces );
  if ( found!=std::string::npos )
    str.erase( 0, found );
  else
    str.clear();
}