C pass a child as a parent to a function-CodePudding

so here's a simplified version of my setup:

class GenericSensor{
public:
    int read(){
        return something;
    }
};

class SpecialSensor : public GenericSensor{
public:
    int read(){
        return somethingElse;
    }
};

and I have a function:

void someFunction(GenericSensor s){
    printf("value is: %d\n", s.read());
}

how do I make someFunction work with GenericSensor, SpecialSensor or any other derived class's object?

CodePudding user response：

You should declare read() as a virtual function which SpecialSensor, or any other derived class, can override.

Moreover, you should not pass GenericSensor around by value, otherwise you will slice the caller's object. Rather, pass it around by pointer or reference instead. So have someFunction() receive s by GenericSensor* pointer or GenericSensor& reference.