Weird pointer issue

[Ending Credits]

I have a line in code that goes:

 

UTNCharacter * newplayer = world.CreatePlayer();
world.player = &newplayer->controller;

 

(Where world.CreatePlayer(); returns a pointer to the UTNCharacter type.)

 

 

However, when I use the following code:

 

UTNCharacter newplayer = world.CreatePlayer();
world.player = &newplayer.controller;

 

(Where world.CreatePlayer(); returns a UTNCharacter object.)

 

The world.player pointer seems to be made null and PositionEntity(*player,...) with the world class methods produces a memory access error.

 

Am I doing something stupid?

[Canardia]

Use STL map instead of pointers, since you will need multiple players also.

[Laurens]

I am far from an expert (learning C++ as I go along with Leadwerks) but I believe your first example creates an object on the heap, whereas your second example creates an object on the stack. Characteristic of the stack is that when "newplayer" goes out of scope, it is no longer valid.

 

Someone will probably come along to correct me

 

Use STL map instead of pointers, since you will need multiple players also.

 

The key in map will always be a pointer. You can't stuff references as a key in a map.

[Canardia]

The key is just a static value, you can use a string or int (enum) as key.

 

It could look like this:

map<string,UTNCharacter> players;
...
players["joe"]=world.CreatePlayer();
players["jane"]=world.CreatePlayer();

[Ending Credits]

I am far from an expert (learning C++ as I go along with Leadwerks) but I believe your first example creates an object on the heap, whereas your second example creates an object on the stack. Characteristic of the stack is that when "newplayer" goes out of scope, it is no longer valid.

 

Someone will probably come along to correct me

 

That would explain it.

[Ending Credits]

Use STL map instead of pointers, since you will need multiple players also.

 

Actually, player is just a reference to the player's character so I can place the camera, all the rest will be done in methods (this is probably a really silly/weird way to do things).

 

I'll have a look at maps though, they look quite usefull.

[VeTaL]

I can recommend you Scott Meyers - Effective STL: 50 Specific Ways to Improve Your Use of the Standard Template Library.