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# SystemDependency

Defines update order relative to other systems.
An object that specifies the update order between multiple systems.

```
enum SystemDependency
```

## Overview

Add instances of `SystemDependency` to your system’s
[`dependencies`](/documentation/RealityKit/System/dependencies) array to indicate whether RealityKit updates
another specified system before or after this system.

## Topics

### Update order

[`case before(any System.Type)`](/documentation/RealityKit/SystemDependency/before(_:))

An update order that requests RealityKit update this system before it
updates another specified system.

[`case after(any System.Type)`](/documentation/RealityKit/SystemDependency/after(_:))

An update order that requests RealityKit update this system after it
updates another specified system.

### Comparisons

### Operators

[`static func == (SystemDependency, SystemDependency) -> Bool`](/documentation/RealityKit/SystemDependency/==(_:_:))

Returns a Boolean value that indicates whether two dependencies are
equal.

## Relationships

### Conforms To

[`Equatable`](/documentation/Swift/Equatable)

[`SendableMetatype`](/documentation/Swift/SendableMetatype)

[`Sendable`](/documentation/Swift/Sendable)

---

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