What's the best way to trim std::string?

Question

I\'m currently using the following code to right-trim all the std::strings in my programs:

std::string s;
s.erase(s.find_last_not_of(\" \\n\\r\\         


        

Answer 1

An elegant way of doing it can be like

std::string & trim(std::string & str)
{
   return ltrim(rtrim(str));
}

And the supportive functions are implemented as:

std::string & ltrim(std::string & str)
{
  auto it =  std::find_if( str.begin() , str.end() , [](char ch){ return !std::isspace(ch , std::locale::classic() ) ; } );
  str.erase( str.begin() , it);
  return str;   
}

std::string & rtrim(std::string & str)
{
  auto it =  std::find_if( str.rbegin() , str.rend() , [](char ch){ return !std::isspace(ch , std::locale::classic() ) ; } );
  str.erase( it.base() , str.end() );
  return str;   
}

And once you've all these in place, you can write this as well:

std::string trim_copy(std::string const & str)
{
   auto s = str;
   return ltrim(rtrim(s));
}