Материал из C\C++ эксперт
double cast operator
#include <iostream>
using namespace std;
class Power {
double b;
int e;
double val;
public:
Power(double base, int exp)
{
b = base;
e = exp;
val = 1;
if(exp==0)
return;
for( ; exp>0; exp--)
val = val * b;
}
Power operator+(Power o) {
double base;
int exp;
base = b + o.b;
exp = e + o.e;
Power temp(base, exp);
return temp;
}
operator double() { return val; } // convert to double
};
int main() {
Power x(4.0, 2);
double a;
a = x; // convert to double
cout << x + 1.2; // convert x to double and add 100.2
cout << "\n";
Power y(3.3, 3), z(0, 0);
z = x + y; // no conversion
a = z; // convert to double
cout << a;
return 0;
}17.2
20730.7"
