///////////////////////////////////////////////////////////////////
// format.cpp - Solution of MT#1-Q3, MT#2-Q3, and MT#3-Q10       //
//                                                               //
// This is a demo showing how to save a stream's format state    //
// and justify with a manipulator.                               //
///////////////////////////////////////////////////////////////////

#include <iostream>

typedef std::ios sios;
typedef std::ostream ostr;

// template argument allows you to save more than one stream state

template<int index>
class iostate
{
public:
  static void stream(sios& stream) { _pStream = &stream; }
  static void save() { if(_pStream) _state = _pStream->flags(); }
  static void restore() { if(_pStream) _pStream->flags(_state); }
private:
  static long _state;
  static sios* _pStream;
};

template <int index>
sios* iostate<index>::_pStream = 0;
template <int index>
long  iostate<index>::_state = 0;

template <unsigned w>
ostr& Left(ostr &out)
{
  out.setf(ostr::left,ostr::adjustfield);
  out.width(w);
  return out;
}

template <unsigned w>
ostr& Right(ostr &out)
{
  out.setf(ostr::right,ostr::adjustfield);
  out.width(w);
  return out;
}

using namespace std;

int main()
{
  std::cout << "\n  stream state = " << cout.flags();
  iostate<1>::stream(std::cout);
  iostate<1>::save();

  std::cout.fill('.');
  std::cout << "\n  " << Left<15> << 3.1415927;
  std::cout << "\n  stream state = " << cout.flags();
  std::cout << "\n  " << Right<10> << -33;
  std::cout << "\n  stream state = " << cout.flags();
  
  iostate<1>::restore();
  std::cout << "\n  stream state = " << cout.flags() << "\n\n";
  return 0;
}