Passing an object to a function gets error

Question

I am trying to pass an object to a function. I got two errors from the function declaration in car.h I am using vs2019, VC++.

overloaded function "Car::Car" is not a type name
syntax error: identifier '{ctor}' <<<<< about the object named car

Engine class

class Engine {
    protected:
        // some variables

    public:
        // default constructor and destructor
        // some function
};

SUV class

class SUV : public Engine {
    protected:
        // some variables

    public:
        // default constructor and deconstructor
        // some function
};

Car class

class Car : public SUV {
    public:
        Car();
        ~Car();
};

Factory class

class Factory {
    public:
        void MakeCar( int x, Car::Car car ); <<<<<< Errors

I really don't know why it doesn't work. Please tell me. Thank you.

After you fix that you have `void MakeCar( int x, Car car );` Are you sure you want to pass by value for that? Also not sure what the purpose of this function is. Does it make a copy, so a copy constructor would be more appropriate. But then what is the `x` parameter? — drescherjm, Nov 25 '20 at 01:51
Just a minor point that might help next time you talk about C++ with other fellow programmers: "deconstructor" is not part of the language -- it's called the _destructor_. :) — paddy, Nov 25 '20 at 01:51
My mistake. I am missing one class. I am changing my question. Sorry about that. — fast_cookies_delivery, Nov 25 '20 at 01:52
drescherjm, That is not the actual code, I try to convert it as close as I can to something that I can post publicly. — fast_cookies_delivery, Nov 25 '20 at 01:57
I did try void MakeCar( int x, Car car);. I got syntax error: identifier 'Car' — fast_cookies_delivery, Nov 25 '20 at 01:58
That means you are missing an include. Probably #include "car.h" — drescherjm, Nov 25 '20 at 01:58
Make sure car.h does not include factory.h. Having a circular header loop is often a cause of that. — drescherjm, Nov 25 '20 at 02:00
This is the inherent problem when beginners try to create simplified examples. Often it ends up in a nonsense question, or just the wrong question. — paddy, Nov 25 '20 at 02:02
Thank, drescherjm, I think that probably the issue. One of the base class include Factory. — fast_cookies_delivery, Nov 25 '20 at 02:02
@paddy I still prefer that to users not even trying to make a minimal example, and posting 100 lines of code. — cigien, Nov 25 '20 at 02:03
Thank you everyone. It is fixed. The reason of causing this error is the base class includes Factory in the header. — fast_cookies_delivery, Nov 25 '20 at 02:06
@cigien I wish I could. Unfortunately I am working on close source project. I can't post it. — fast_cookies_delivery, Nov 25 '20 at 02:07
No, my comment was not suggesting that you post all your code :) Quite the opposite in fact. You did the right thing by trying to make a simplified minimal example. — cigien, Nov 25 '20 at 02:09
In C++ you'll often see factory functions return an allocated pointer to the base type if you're looking to use inheritance. Like `Engine* MakeCar(int x)` where that figures out what to do and returns the appropriate thing. — tadman, Nov 25 '20 at 02:36

Passing an object to a function gets error

0 Answers0