长整数类，数据成员有一个指针，一个整数size，可以存放100位以上整数，可以做加法乘法运算.zip

// Fig. 21.3: fig21_03.cpp // Demonstrating the const_cast operator. #include <iostream> using std::cout; using std::endl; class ConstCastTest { public: void setNumber( int ); int getNumber() const; void printNumber() const; private: int number; }; void ConstCastTest::setNumber( int num ) { number = num; } int ConstCastTest::getNumber() const { return number; } void ConstCastTest::printNumber() const { cout << "\nNumber after modification: "; // the expression number-- would generate compile error // undo const-ness to allow modification const_cast< ConstCastTest * >( this )->number--; cout << number << endl; } int main() { ConstCastTest x; x.setNumber( 8 ); // set private data number to 8 cout << "Initial value of number: " << x.getNumber(); x.printNumber(); return 0; } /************************************************************************** * (C) Copyright 2000 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. * *************************************************************************/