Trying to copy the pointer to a list, getting “cannot convert … to … in initialization” error

Question

I want my Bullet class to have access to a list of Ship, so I have a static variable that is a pointer to the list object.

class Bullet {
    ...
    static list<Ship*>* enemyList;
    ...
}

Declaring the list,

std::list<Ship*> enemyList;

Finally, I provide the definition for my static variable:

std::list<Ship*>* Bullet::enemyList = &enemyList;

However, the compiler gives the following error:

error: cannot convert `std::list<Ship*, std::allocator<Ship*> >**' to `std::list<Ship*, std::allocator<Ship*> >*' in initialization|

By changing my definition to the following, the program compiles but segfaults when the function requiring the list is called:

std::list<Ship*>* Bullet::enemyList = enemyList;  //no &

Which leads me to believe that there is an error in my understanding and usage of std::list, but I'm not sure what that is. Thanks!

EDIT : Resolved

As pointed out by Matt McNabb below, enemyList on the right hand side of

std::list<Ship*>* Bullet::enemyList = &enemyList;

referenced the enemyList on the left hand side rather than the enemyList I wanted to call outside of the class. Using distinct names solved this issue.

Answer 1

Firstly it sounds like you want:

static list<Ship> enemyList;

It's not clear why you want pointers to be involved. If you use this form then all your other questions are rendered moot, but to answer it anyway:

This line makes no sense:

std::list<Ship*>* Bullet::enemyList = &enemyList;

You're trying to initialize the list to point to itself, which is not possible (since the list contains Ship* , not list<Ship*> ). The declaration would be:

list<Ship*> *Bullet::enemyList;

and you would also have to make that pointer point somewhere (by default it will be a null pointer).

Your second version compiles but it is just like writing:

int x = x;

hopefully you can understand why this is a problem.