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// Fig. 7.11: fig07_11.cpp
// Friends can access private members of a class.
#include <iostream>
using std::cout;
using std::endl;
// Count class definition
// (note that there is no friendship declaration)
class Count {
friend void setX( Count &, int ); // friend declaration
public:
// constructor
Count()
: x( 0 ) // initialize x to 0
{
// empty body
} // end constructor Count
// output x
void print() const
{
cout << x << endl;
} // end function print
private:
int x; // data member
}; // end class Count
// function setX can modify private data of Count
// because setX is declared as a friend of Count
void setX( Count &c, int val )
{
c.x = val; // legal: setX is a friend of Count
} // end function setX
int main()
{
Count counter; // create Count object
cout << "counter.x after instantiation: ";
counter.print();
setX( counter, 8 ); // set x with a friend
cout << "counter.x after call to setX friend function: ";
counter.print();
return 0;
} // end main
/**************************************************************************
* (C) Copyright 1992-2003 by Deitel & Associates, Inc. and Prentice *
* Hall. All Rights Reserved. *
* *
* DISCLAIMER: The authors and publisher of this book have used their *
* best efforts in preparing the book. These efforts include the *
* development, research, and testing of the theories and programs *
* to determine their effectiveness. The authors and publisher make *
* no warranty of any kind, expressed or implied, with regard to these *
* programs or to the documentation contained in these books. The authors *
* and publisher shall not be liable in any event for incidental or *
* consequential damages in connection with, or arising out of, the *
* furnishing, performance, or use of these programs. *
*************************************************************************/
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