///////////////////////////////////////////////////////////////////////
// oSockProto.cpp - helper demonstration for Project #3              //
//   Shows how to implement insertion operator for a socket handler  //
//   derived from ostringstream that inserts into the socket in one  //
//   invocation.                                                     //
//                                                                   //
// Jim Fawcett, CSE687 - Object Oriented Design, Spring 2004         //
///////////////////////////////////////////////////////////////////////

#include <sstream>
#include <iostream>
#include <string>

///////////////////////////////////////////////////////////////////////
// class message - demonstrates sending user defined types to socket

class message : public std::string
{
public:
  message(const std::string& s) : std::string(
    std::string("<msg>") + s + std::string("</msg>")
    ) {}
};

// base class std::string provides:
//   ostream& operator<<(ostream&, const std::string&)
// used in template <typename T> oSockProto::operator<<(const T &t)

///////////////////////////////////////////////////////////////////////
//  class oSockProto demonstrates how to implement insertion
//                   that sends to socket

class oSockProto : private std::ostringstream
{
public:
  template <typename T>
  oSockProto& operator<<(const T& t);
private:
  void send();
};

//----< simulates sending to socket >----------------------------------
//
//  extract string from base and send
//
void oSockProto::send()
{
  std::cout << this->str();  // in real class this will go to socket
}
//----< insertion operator >-------------------------------------------
//
//  will accept any type that overloads operator<<, used with base class
//
template <typename T>
oSockProto& oSockProto::operator<<(const T &t)
{
  std::ostringstream& base = *this;  // get base part
  base << t;  // convert t to string using ostringstream converters
  send();     // extract and send string
  str("");    // empty buffer for next input
  return *this;
}
//
void main()
{
  oSockProto osp;
  osp << "\n  Simulate sending to socket "
      << "\n ============================\n";

  // What goes into osp are a double, int, C string, and user-defined message.
  // What comes out, on cout, are four strings.  
  // Conversions are compliments of your friendly ostringstream class.

  osp << "\n  " << 3.1415927;
  osp << "\n  " << 2;
  osp << "\n  " << "now is the hour";
  osp << "\n  " << message("a message");

  std::cout << "\n\n";
}