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# IOUserClientMethodDispatch

A structure that specifies how to validate the arguments passed to a client method function.

```
struct IOUserClientMethodDispatch;
```

## Discussion

Used this structure to specify the validation checks to perform on the fields of the IOUserClientMethodArguments structure passed to an [`IOUserClientMethodFunction`](/documentation/DriverKit/IOUserClientMethodFunction).

## Topics

### Getting the Dispatch Properties

[`function`](/documentation/DriverKit/IOUserClientMethodDispatch/function)

The function to call after validating all of the specified values.

[`checkCompletionExists`](/documentation/DriverKit/IOUserClientMethodDispatch/checkCompletionExists)

An integer value indicating whether to check for the existence of a completion action.

[`checkScalarInputCount`](/documentation/DriverKit/IOUserClientMethodDispatch/checkScalarInputCount)

The expected number of scalar inputs.

[`checkStructureInputSize`](/documentation/DriverKit/IOUserClientMethodDispatch/checkStructureInputSize)

The expected size of the scalar inputs.

[`checkScalarOutputCount`](/documentation/DriverKit/IOUserClientMethodDispatch/checkScalarOutputCount)

The expected number of scalar outputs.

[`checkStructureOutputSize`](/documentation/DriverKit/IOUserClientMethodDispatch/checkStructureOutputSize)

The expected size of the scalar outputs.


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