I have a struct that stores a variety of measurements, and the accuracy of measurements (i.e. 10 cm ± 2 cm). Not all measurements are necessarily measuring the same thing (angle, length, speed, etc.) Is there a best practice for storing such information? I started with:

```
struct Example {
let x: Double
let xAccuracy: Double
let y: CGPoint
let yAccuracy: Double // radius around y
let z: Int
let zAccuracy: Int
}
```

It feels off to have two fields for every property. I'm considering something like this:

```
struct ApproximateValue<Value, Accuracy> {
let value: Value
let accuracy: Accuracy
}
struct Example2 {
let x: ApproximateValue<Double, Double>
let y: ApproximateValue<CGPoint, Double>
let z: ApproximateValue<Int, Int>
}
```

Any suggestions?