How do I set a member of a copied class instance?

June 18, 2022

I am currently working on an instance system, so far this is something I tried:

//[...]
#include <string>
#include <list>

class Instance { // Instance class
public:
    std::string Name;
    std::string Type;
    SDL_Texture* Texture; // All this is for a list for an SDL renderer.
    int x;
    int y;
};

class instances {
public:
    Instance New(std::string Name, std::string Type) {
        Instance newInstance; // Clone the class? Doesn't raise error.
        Instance::Name = "Test"; // Set a variable from the cloned class. Error: "a nonstatic member reference must be relative to a specific object"
    };

    std::list<int> list = {}; // Ignore this...
};
//[...]

You will be able create instances with the "New" function shown above, which should return a copy of the "Instance" class (also above).

Unfortunately it raises an error as I wrote in the script comments.

>Solution :

The problem is that Name is a non-static data member of class Instance so you would need an object of type Instance for which you can access that field Name.

Additionally you should add a return statement inside the function New.

The correct way would be as shown below:

Instance New(std::string Name, std::string Type) {
        Instance newInstance; // create object of type Instance
//-----------------v--------------------->used . instead of ::
        newInstance.Name = "Test"; 
    
        return newInstance;//added return statement
    };