BMX to CPP

John J.

Budman: Thanks for clarifying the stack vs. pure static data.

BTW, when I say anything that's not allocated by "new" or "malloc()" is basically static data, I mean it doesn't require a separate allocation. In a game, most everything is going to be dynamically allocated at some point (your entities, for example), so what matters is how many heap allocations it takes when loading a new entity, for example. By using all non-dynamic variables, you can reduce it to 1 (and you can actually reduce the number of allocations below 1 per object if you implement some sort of pooling strategy).

What is the equivalent in CPP to a link object?

Here is my entity constructor and destructor. You can see when it is created it gets added to the world entities list. How can I remove it from the list upon deletion?:

I don't know what a link object is, but based on your code I think the equivalent is an iterator:

	class Entity {
		public:
			Entity();
			~Entity();

		private:
			list<Entity*>::iterator link;
	};

	Entity::Entity() {
		pWorld = World::current();
		pWorld->entities.push_front( this );
		link = pWorld->entities.begin();  //returns an iterator at the newly added item
	}
	
	void ~Entity() {
		pWorld->entities.erase(link);
		pWorld = null;
	}

I didn't try running this, but hopefully it doesn't have any errors. Note: There may be a better way to do this, but I'm not sure. Personally I think they should have made it so push_front() returns an iterator at the newly added item.