// A2.2.cpp : Defines the entry point for the console application.
//
// Please provide the definition of a template-based class that provides
// access to a shared value of some type, specified when the using 
// application is compiled.  Wherever an object of this type is declared 
// it provides access to the same value of the template type.

#include "stdafx.h"
#include <iostream>
using namespace std;

template <class T> class transporter {

public:
  transporter() {}
  T& value() { return val; }
private:
  static T val;
};

template <class T> T transporter<T>::val;

template <class T, int i> class alternateTransporter {

public:
  alternateTransporter() {}
  T& value() { return val; }
private:
  static T val;
};

template <class T, int i> T alternateTransporter<T,i>::val;

ostream& operator<<(ostream& out, std::string& s) {
  out << s.c_str();
  return out;
}

int _tmain(int argc, _TCHAR* argv[])
{
  cout << "\n  Exam A2 - Question #2 "
       << "\n =======================\n";

  transporter<double> t1; t1.value() = 3.1415927;
  transporter<double> t2;
  cout << "\n  value transported from t1 to t2 = " << t2.value();

  // Note that any module that includes the transporter class declaration
  // will have access to this value.
  //
  // We can provide access to more than one value of type T by defining 
  // template<class T, int i> 

  alternateTransporter<string,1> tstring11;
  tstring11.value() = "first shared string";

  alternateTransporter<string,1> tstring12;
  cout << "\n  string value transported from tstring11 to tstring12 = \"" 
       << tstring12.value() << "\"";

  alternateTransporter<string,2> tstring21;
  tstring21.value() = "second shared string";

  alternateTransporter<string,2> tstring22;
  cout << "\n  string value transported from tstring21 to tstring22 = \"" 
       << tstring22.value() << "\"";

  cout << "\n\n";
  return 0;
}