Join a container of strings into a single one, with a delimiter

join_string.cpp

namespace
{
  struct add_delimiter
  {
    add_delimiter( const std::string& d )
    { delimiter = d; }
    
    std::string operator()( const std::string& lhs, const std::string& rhs )
    { return lhs + (lhs.empty() ? "" : delimiter) + rhs; }
    
    std::string delimiter;
  };
}

void join( const std::vector<std::string>& list, std::string& str, const std::string delimiter="" )
{
  str = std::accumulate( list.begin(), list.end(), std::string(""), add_delimiter(delimiter) );
}