diff options
Diffstat (limited to 'Bachelor/Prog1/examples/ch07/Fig07_11')
| -rw-r--r-- | Bachelor/Prog1/examples/ch07/Fig07_11/Fig07_11.cpp | 72 |
1 files changed, 72 insertions, 0 deletions
diff --git a/Bachelor/Prog1/examples/ch07/Fig07_11/Fig07_11.cpp b/Bachelor/Prog1/examples/ch07/Fig07_11/Fig07_11.cpp new file mode 100644 index 0000000..995bc86 --- /dev/null +++ b/Bachelor/Prog1/examples/ch07/Fig07_11/Fig07_11.cpp @@ -0,0 +1,72 @@ +// 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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