//16. Входни и изходни потоци: заглавни файлове и класове в 
//потоковата библиотека; потоков вход и изход - операции и функции;
//потокови манипулатори; състояния на потоците.  
//
// Fig. 12.3: fig12_03.cpp
// Printing the address stored in a char * variable.
#include <iostream>

using std::cout;
using std::endl;

int main()
{
   char *word = "test";

   // display value of char *, then display value of char *
   // static_cast to void *
   cout << "Value of word is: " << word << endl
        << "Value of static_cast< void * >( word ) is: " 
        << static_cast< void * >( word ) << endl;

   return 0;

} // end main
/****/
// Fig. 12.4: fig12_04.cpp 
// Using member functions get, put and eof.
#include <iostream>

using std::cout;
using std::cin;
using std::endl;

int main()
{
   int character; // use int, because char cannot represent EOF

   // prompt user to enter line of text
   cout << "Before input, cin.eof() is " << cin.eof() << endl
        << "Enter a sentence followed by end-of-file:" << endl;

   // use get to read each character; use put to display it
   while ( ( character = cin.get() ) != EOF )
      cout.put( character );

   // display end-of-file character
   cout << "\nEOF in this system is: " << character << endl;
   cout << "After input, cin.eof() is " << cin.eof() << endl;

   return 0;

} // end main
/****/
// Fig. 12.5: fig12_05.cpp 
// Contrasting input of a string via cin and cin.get.
#include <iostream>

using std::cout;
using std::cin;
using std::endl;

int main()
{
   // create two char arrays, each with 80 elements
   const int SIZE = 80;
   char buffer1[ SIZE ];
   char buffer2[ SIZE ];

   // use cin to input characters into buffer1
   cout << "Enter a sentence:" << endl;
   cin >> buffer1;

   // display buffer1 contents
   cout << "\nThe string read with cin was:" << endl
        << buffer1 << endl << endl;
 
   // use cin.get to input characters into buffer2
   cin.get( buffer2, SIZE );

   // display buffer2 contents
   cout << "The string read with cin.get was:" << endl 
        << buffer2 << endl;

   return 0;

} // end main
/****/
// Fig. 12.7: fig12_07.cpp 
// Unformatted I/O using read, gcount and write.
#include <iostream>

using std::cout;
using std::cin;
using std::endl;

int main()
{
   const int SIZE = 80;
   char buffer[ SIZE ]; // create array of 80 characters

   // use function read to input characters into buffer
   cout << "Enter a sentence:" << endl;
   cin.read( buffer, 20 );

   // use functions write and gcount to display buffer characters
   cout << endl << "The sentence entered was:" << endl;
   cout.write( buffer, cin.gcount() );
   cout << endl;

   return 0;

} // end main
/****/
// Fig. 12.11: fig12_12.cpp
// Creating and testing user-defined, nonparameterized 
// stream manipulators.
#include <iostream>

using std::ostream;
using std::cout;
using std::flush;

// bell manipulator (using escape sequence \a)
ostream& bell( ostream& output )
{
   return output << '\a';  // issue system beep
}

// carriageReturn manipulator (using escape sequence \r)
ostream& carriageReturn( ostream& output )
{
   return output << '\r';  // issue carriage return
}

// tab manipulator (using escape sequence \t)
ostream& tab( ostream& output )
{
   return output << '\t';  // issue tab
}

// endLine manipulator (using escape sequence \n and member
// function flush)
ostream& endLine( ostream& output ) 
{ 
   return output << '\n' << flush;  // issue end of line
}

int main()
{
   // use tab and endLine manipulators
   cout << "Testing the tab manipulator:" << endLine
        << 'a' << tab << 'b' << tab << 'c' << endLine;

   cout << "Testing the carriageReturn and bell manipulators:"
        << endLine << "..........";

   cout << bell; // use bell manipulator

   // use ret and endLine manipulators
   cout << carriageReturn << "-----" << endLine;

   return 0;

} // end main
/****/
// Fig. 12.22: fig12_22.cpp 
// Testing error states.
#include <iostream>

using std::cout;
using std::endl;
using std::cin;

int main()
{
   int integerValue;

   // display results of cin functions
   cout << "Before a bad input operation:"
        << "\ncin.rdstate(): " << cin.rdstate()
        << "\n    cin.eof(): " << cin.eof()
        << "\n   cin.fail(): " << cin.fail()
        << "\n    cin.bad(): " << cin.bad()
        << "\n   cin.good(): " << cin.good()
        << "\n\nExpects an integer, but enter a character: ";

   cin >> integerValue; // enter character value
   cout << endl;

   // display results of cin functions after bad input
   cout << "After a bad input operation:"
        << "\ncin.rdstate(): " << cin.rdstate()
        << "\n    cin.eof(): " << cin.eof()
        << "\n   cin.fail(): " << cin.fail()
        << "\n    cin.bad(): " << cin.bad()
        << "\n   cin.good(): " << cin.good() << endl << endl;

   cin.clear(); // clear stream

   // display results of cin functions after clearing cin
   cout << "After cin.clear()"
        << "\ncin.fail(): " << cin.fail()
        << "\ncin.good(): " << cin.good() << endl;

   return 0;

} // end main