How to know what two kinds of object is colliding?

[coco_pen]

In my game there are a lot of kinds of physics objects.Now I add tag for every object class.So in onContactBegin,I need write a very long list to judge what kind of object is contact.getShapeA and contact.getShapeB.
Is there a easy way to do this?

For example in cocos2d-ipone
-(BOOL)ccPhysicsCollisionBegin:(CCPhysicsCollisionPair *)pair ClassA:(CCNode *)nodeA ClassB:(CCNode *)nodeB
So it’s already know nodeA is ClassA and nodeB is ClassB

[amin13a]

you can create a base class with physics property and write contact code in classes and not in contact listener.
See this post:

Collision 2 object in box2d

I have two objects : GameObject* A & GameObject* B, each objet have two animation:idle and colli, with each animation, object have state: m_stateidle and m_statecolli . i want one condition : “When object A in m_statecolli and object B in m_stateidle OR object A in m_statedile and object B in m_statecolli”, two object collide each other i use ContactListerner.h vs ContactListerner.cpp class ContactListener : public b2ContactListener { public: ContactListener(); ~ContactListener(); …