C++ Problem: Class Promotion using derived class
- by Michael Fitzpatrick
I have a class for Float32 that is derived from Float32_base
class Float32_base {
public:
// Constructors
Float32_base(float x) : value(x) {};
Float32_base(void) : value(0) {};
operator float32(void) {return value;};
Float32_base operator =(float x) {value = x; return *this;};
Float32_base operator +(float x) const { return value + x;};
protected:
float value;
}
class Float32 : public Float32_base {
public:
float Tad() {
return value + .01;
}
}
int main() {
Float32 x, y, z;
x = 1; y = 2;
// WILL NOT COMPILE!
z = (x + y).Tad();
// COMPILES OK
z = ((Float32)(x + y)).Tad();
}
The issue is that the + operator returns a Float32_base and Tad() is not in that class. But 'x' and 'y' are Float32's.
Is there a way that I can get the code in the first line to compile without having to resort to a typecast like I did on the next line?
