Question

I have a class which takes two arguments on it’s constructor, an int and a void(*)(void) so normally when I need to call it I do it like this:

obj_child (int_value, pointer_to_foo);

Now what I want is to instantiate the obj_child with constant arguments, within another class.

So I tried:

class obj_parent
{

    private:

        obj_child child_instantiation (int_value, pointer_to_foo);

};

but this seems to give me two compiler errors on the line I declare child_instantiation so I guess the arguments can’t be passed there but somewhere else.

Mind you child_instantiations are supposed to have the same arguments for all obj_parent instantiations, so they shouldn’t be passed as obj_parent constructor arguments.

Declaring the class pointer and then creating a new one on the heap compiles, but I don’t want to do it that way and I don’t know if it works (my debugger can’t watch the reference so it’s very hard to monitor it’s values).

class obj_parent
    {

        private:

            obj_child *child_instantiation;

    };

obj_parent::
obj_parent (void)
{

    child_instantiation = new obj_child child_instantiation (int_value, pointer_to_foo);


}

Thanks!

(Please don’t mind the semantics, child – parent has nothing to do with inheritance, just couldn’t think better names right now)

Answer 1

You have to initialize the object in the constructor of the class.

obj_parent() : child_instantiation (int_value, pointer_to_foo) {}