# b2ContactID Union Reference

Contact ids to facilitate warm starting. More...

`#include <b2Collision.h>`

List of all members.

## Classes
struct | Features
| The features that intersect to form the contact point. More...
## Public Attributes
struct b2ContactID::Features | features
| The features that intersect to form the contact point.
uint32 | key
| Used to quickly compare contact ids.

## Detailed Description

Contact ids to facilitate warm starting.

## Member Data Documentation

struct b2ContactID::Features b2ContactID::features

The features that intersect to form the contact point.

uint32 b2ContactID::key

Used to quickly compare contact ids.

The documentation for this union was generated from the following file:

- Box2D/Box2D/Collision/b2Collision.h