I’ve written a custom ValueTransformer to store an object type that does not receive automatic compliance for SwiftData:

• How to use SwiftData ValueTransformer with a custom NSMeasurement Dimension Unit?

I now want to store collections of that same type as variables on a SwiftData model:

@Model
class TestModel {
    // Works after adding custom MeasurementTransformer
    @Attribute(.transformable(by: MeasurementTransformer.self)) let measurement: NSMeasurement

    // Not working
    let measurementArray: [NSMeasurement]
    let measurementDict: [String: NSMeasurement]
    
    init(measurement: NSMeasurement, measurementArray: [NSMeasurement], measurementDict: [String : NSMeasurement]) {
        self.measurement = measurement
        self.measurementArray = measurementArray
        self.measurementDict = measurementDict
    }
}

This throws errors for the Array and Dictionary:

Referencing instance method ‘setValue(forKey:to:)’ on ‘Array’ requires that ‘NSMeasurement’ conform to ‘PersistentModel’
Referencing instance method ‘getValue(forKey:)’ on ‘Array’ requires that ‘NSMeasurement’ conform to ‘PersistentModel’

Is there any special syntax for @Attribute(.transformable(by: (or any other way) to share code between the single-object transformer and a transformer for when that type is packed into an array or dictionary? Or do I need to write entirely new ValueTransformers for every situation where that type appears in a collection?