Question

So i have a class name repository which is just a simple array.Here is a part of the class:

template<class Element>
class repository {
private:
    int size;
    int capacity;
    Element* elements;

I have another class named participant.I want to have a repository of participants and perform actions on that repository using a new class named controller.But I don`t know how to declare the type of the repository in the controller.

Here is a part of the class participant:

class participant {
private:
    int position;
    int score;

And here is a part from the class controller:

#include "repository.h"
#include "participant.h"
class controller {
private:
    repository repository;
    repository temporary;
    void createCopy();
public:
    controller();
    controller(repository repo);

And I get the errors:

-invalid use of template-name ‘repository’ without an argument list int the lines with repository repository and repository temporary;

-expected ‘)’ before ‘repo’ in the line with controller(repository repo);

How should I declare the type for the repository and temporary in the declaration of class controller so that I won`t get any other errors?

Answer 1

Repository is a class template, so you need to declare your data members as

private:
    repository<SomeType> repository; // but this hides repository name
    repository<SomeType> temporary;  // repository has another meaning now!

where SomeType in this case is probably participant. repository by itself doesn’t name a type, repository<int> or repository<std::string> etc. does. Next, your data member name cannot be repository, since that is the template name needed for temporary. So change the name of the data member:

private:
    repository<SomeType> repo_;

Likewise, your constructor must take a type:

controller(repository<participant> repo);

although you probably want to pass repo by const reference:

controller(const repository<participant>& repo);