CODEWITHSUNDEEP
c++
Abarnett
Abarnett

Reputation: 327

C++ No instance of the constructor matches the argument list?

I am learning class inheritance, and I am struggling to figure out a small problem. I have two classes

class OrderList {
private:
    std::vector<AbstractClass*> elements;


public:
    OrderList(const std::vector<AbstractClass*>& list){
    //  for (auto &i : list)
    //      elements.push_back(i);
    }

    OrderList(const OrderList& ol);

    OrderList& operator=(const OrderList&);

    virtual ~OrderList(){};


};

class DerivedOrderList : public OrderList {
    DerivedOrderList(std::vector<AbstractClass*>& list) : OrderList(list){}

    DerivedOrderList(const DerivedOrderList&);

    DerivedOrderList& operator=(const DerivedOrderList&);

    virtual ~DerivedOrderList(){};
};

Then, my main function calls on DerivedOrderList as such:

DerivedOrderList myOrderList = DerivedOrderList(myVector);

I am getting an error: No instance of constructor "DerivedOrderList::DerivedOrderList" that matches the arguments

What might be causing this?

Upvotes: 0

Views: 6821

Answers (3)

CoconutFred
CoconutFred

Reputation: 454

std::vector<AbstractClass*> is not the same as std::vector<DerivedClass*>. The compiler creates a completely different class for each separate template implementation.

Why don't you just provide overloaded constructors DerivedOrderList::DerivedOrderList(std::vector<DerivedClass*>&) and OrderList::OrderList(std::vector<DerivedClass*>&)?

Upvotes: 1

Tony J
Tony J

Reputation: 651

Constructor in DerivedOrderList needs to be public.

Edit: Also see NathanOliver's comment and Rob K's answer regarding type of myVector.

Upvotes: 3

Rob K
Rob K

Reputation: 8926

OrderList(const std::vector<AbstractClass*>& list) takes a const reference.

DerivedOrderList(std::vector<AbstractClass*>& list) takes a mutable reference. Change it to DerivedOrderList(const std::vector<AbstractClass*>& list)

Also, I'd recommend typdefing your vector<AbstractClass*> somewhere. You use it in a lot of places, so Don't Repeat Yourself.

ETA: Also this DerivedOrderList myOrderList = DerivedOrderList(myVector); should be DerivedOrderList myOrderList( myVector ); This is not Java or C#.

Upvotes: 3

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