How do I use the emplace_back function of a vector?

Question

Edit: Changed it to only one question, thanks for the feedback!

I have this vector

vector<Artifact> art;


art.emplace_back("Ipad", 349.99);
art.emplace_back("Gameboy", 29.99);
art.emplace_back("Xbox", 229.99);
art.emplace_back("SamsungTV", 559.99);
art.emplace_back("AirCon", 319.99);

These items give me an error

C2661   'Artifact::Artifact': no overloaded function takes 2 arguments

I don't understand why it's giving me this error, I have a constructor with 7 arguments but I only need Name and Price for what I'm trying to do.

Edit: This is the Minimal reproducible example :

class Item {
public:

virtual double GetTotalPrice();

};

//Class artifact now inherits Item
class Artifact : public Item
{
private:

string GUID;
string Name;
string Description;
string Category;
double Price;
double Discount;
enum DiscountType { Amount, Percentage };
int Quantity;

public:
//Constructor
Artifact(string GUID, string Name, string Description, string Category, double Price, double Discount,  int Quantity)
{
    this->GUID = GUID;
    this->Name = Name;
    this->Description = Description;
    this->Category = Category;
    this->Price = Price;
    this->Discount = Discount;
    this->Quantity = Quantity;

}
//default constructor
Artifact();

void set_name(const string& name)
{
    Name = name;
}

void set_price(double price)
{
    if (Price > 0)
    {
        Price = price;
    }

    else cout << "Price cannot be negative!";


};

int main()
{


vector<Artifact> art;

art.emplace_back("Ipad", 349.99);
art.emplace_back("Gameboy", 29.99);
art.emplace_back("Xbox", 229.99);
art.emplace_back("SamsungTV", 559.99);
art.emplace_back("AirCon", 319.99);



return 0;

}

Answer 1

Basically, the error you are getting is because you have two constructors (one the default taking 0 arguments, and another the 7 parameter version), but you only pass two values to emplace_back. The values passed to emplace_back get forwarded to the constructor of Artifact.

There's two possible ways around this. First, is to create another constructor which just takes in the two values, like so:

Artifact(string Name, double Price) : Artifact("", Name, "", "", Price, 0., 0 ) {}

Alternatively, you can modify your existing 7 parameter constructor to use default values

// note the reordering of parameters here
Artifact(string name, double Price, string GUID= "", 
         string Description = "", string Category = "", 
         double Discount = 0.0, int Quantity = 0) { … }