Brtdku

I am working on building my own vector class similar to the vector you would find the C++ STL. In my header file have two classes, my vector class and my iterator class, which is a nested template class. I am wondering what is the proper syntax is for the return type for a nested iterator class. In this case with my code, I am looking for the right way to write the proper return type syntax for my begin() function and my end() function, both of which are in my vector class. Both begin() and end() are supposed to have return type of vector <T> :: iterator but that does not seem to be working. Here is how my code is currently set up.

template <class T>

iterator;



/************************************************

 * VECTOR

 * A class that holds stuff

 ***********************************************/

template <class T>

class vector

{

public:

   // code removed for brevity



   // Methods of the Vector class

   vector <T> :: iterator begin();

   vector <T> :: iterator end();





private:

   // Code removed for brevity

};



/**************************************************

* VECTOR ITERATOR

* An iterator through array

*************************************************/

template <class T>

class vector <T> :: iterator

{

    // ...code removed for brevity

};

Further, do I have the right code for the following two lines which are at the top of my .h file?

template <class T>

iterator;

Or would it be this?

template <class T>

vector <T> :: iterator;

Thanks!

You can simply move the definition of iterator into vector:

template <class T>

class vector {

public:

    class iterator {

        /* How you implement a iterator of type T */

    };



    iterator begin(); // for example



    // other fantastic stuff

};



template <class T>

vector<T>::iterator vector<T>::begin()

{

    // whatever

}

If you want to not define the iterator inside, this may do:

template <class T>

class vector {

public:

    class iterator; // only a declaration



    iterator begin(); // same



    // other fantastic stuff

};



template <class T>

class vector<T>::iterator {

    // the actual definition goes here

};



template <class T>

vector<T>::iterator vector<T>::begin()

{

    // same

}

Alternatively, you can also define iterator separately
and make vector::iterator an alias:

template <class T>

class iterator { /* real definition */ };



template <class T>

class vector {

public:

    using iterator = ::iterator<T>;

    // or typedef ::iterator<T> iterator;



    iterator begin(); // still the same



    // same fantastic stuff

};



template <class T>

vector<T>::iterator vector<T>::begin()

{

    // all the same

}

Hope this helps.