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# MTKTextureLoader.ArrayCallback

The signature for the block executed after an asynchronous loading operation for multiple textures has completed.

```
typealias ArrayCallback = ([any MTLTexture], (any Error)?) -> Void
```

## Discussion

The block parameters are defined as follows:

- textures: An array of <doc://com.apple.documentation/documentation/Metal/MTLTexture> objects whose order corresponds to the requested textures. If an error occurs when loading a texture, an <doc://com.apple.documentation/documentation/Foundation/NSNull> object occupies its place in the array.
- error: If all texture loading operations were successful, this value is `nil`; otherwise, this parameter holds an <doc://com.apple.documentation/documentation/Foundation/NSError> object that describes the first problem that occurred. (Which element in the input array the error corresponds to is undefined.)

---

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