How to pass derived object in function as base object in C++ [closed]

Answer 1

this is a pointer, but your function expects an object. So dereference the pointer to get the object:

equationSolver::method1(*this, dt);
                        ^

I suspect that the function should probably take the equation by reference (or maybe even pointer) rather than value; but that's just a hunch based on little information.

Answer 2

Shouldn't it be

equationSolver::method1(*this, dt);

Or better yet, make that function to accept a pointer:

class equationSolver{
public:
    static void method1(equation* eq, double dt);
}

Then your original call should work.

Update:

Also you probably want public inheritance:

class simpleMotion : public equation

Answer 3

You do realize that this

static void method1(equation eq, double dt);

is expecting a object of equation instead of pointer to eq

so if you just change this method to

static void method1(equation* eq, double dt);

the following should work as is.

equationSolver::method1(this, dt); // i am getting error here...

because simpleMotion IS_A equation