Overload the cast operator from custom class to int - C++ Class

C++ examples for Class:Operator Overload

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Description

Overload the cast operator from custom class to int

Demo Code

#include <iostream>
using namespace std;
class Box {/* w w w  .j a  v a 2s.com*/
   int x, y, z; // 3-D coordinates
   public:
   Box() { x = y = z = 0; }
   Box(int i, int j, int k) { x = i; y = j; z = k; }
   // A conversion to int.
   operator int() { return x + y + z; }
   // Let the overloaded inserter be a friend.
   friend ostream &operator<<(ostream &strm, Box op);
};
// The Box inserter is a non-member operator function.
ostream &operator<<(ostream &strm, Box op) {
   strm << op.x << ", " << op.y << ", " << op.z << endl;
   return strm;
}
// Return the negation of v.
int neg(int v) {
   return -v;
}
// Return true if x is less than y.
bool lt(int x, int y) {
   if(x < y) return true;
   return false;
}
int main()
{
   Box objA(1, 2, 3), objB(-1, -2, -3);
   int result;
   cout << "Value of objA: " << objA;
   cout << "Value of objB: " << objB;
   cout << endl;
   // Use objA in an int expression.
   cout << "Use a Box object in an int expression: ";
   result = 10 + objA;
   cout << "10 + objA: " << result << "\n\n";
   // Pass objA to a function that takes an int argument.
   cout << "Pass a Box object to an int parameter: ";
   result = neg(objA);
   cout << "neg(objA): " << result << "\n\n";
   cout << "Compare the sum of the coordinates by use of lt(): ";
   if(lt(objA, objB))
      cout << "objA less than objB\n";
   else if(lt(objB, objA))
   cout << "objB less than objA\n";
   else
      cout << "objA and objB both sum to the same value.\n";
      return 0;
}

Result


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