Question

I am working with an abstract base class implementing a set of system tests. In simplified form, the class declaration is:

class Test_Class
{
    Test_Class();
    ~Test_Class();

    Run_Test(void * param_set = NULL) = 0;
}

The base class requires the implementation of the Run_Test function which allows a user to pass in an arbitrary data structure as a void pointer and cast it to the appropriate type inside the body of Run_Test in a child class, in order to allow different tests to use different data structures, e.g. a float in one test vs a list of ints in another.

This is cumbersome and seems like an incredibly C-like way of doing things. Is there a better way of using inheritance or other language utilities?

Note: Due to customer constraints, this program is not allowed access to the STL or the Boost libraries.

Answer 1

Yes. User doesn’t pass in an arbitary data structure but can make an arbitrary data structure by extending your base class.

class Test_Class {
    Run_Test(const Config& config);
};

client code:

class MyConfig : public Config {
    //...
};

Another option is templates. You can accomplish many common tasks with either, I’m not sure which is ideal in this situation so I’ll leave it to other answers or to you to research that if you go this route.