---
title: "appendInterpolation(_:privacy:attributes:)"
framework: os
role: symbol
role_heading: Instance Method
path: "os/osloginterpolation/appendinterpolation(_:privacy:attributes:)-3czd2"
---

# appendInterpolation(_:privacy:attributes:)

Appends an interpolated object description with the specified attributes.

## Declaration

```swift
mutating func appendInterpolation(_ argumentObject: @autoclosure @escaping () -> NSObject, privacy: OSLogPrivacy = .auto, attributes: String)
```

## Parameters

- `argumentObject`: The interpolated object, which the system automatically wraps in a closure. The object itself doesn’t appear in the log message. Instead, the system calls the object’s doc://com.apple.documentation/documentation/ObjectiveC/NSObjectProtocol/description method and incorporates the value it returns.
- `privacy`: The privacy level of the interpolated value, which the system applies when it renders the value in a log message. For more information, see doc://com.apple.os/documentation/os/OSLogPrivacy. The default value is doc://com.apple.os/documentation/os/OSLogPrivacy/auto.
- `attributes`: Additional information about the interpolated value. Tools that process log messages interpret these attributes, which you typically provide as key-value pairs. For example, Instruments processes any e_ngineering types_ you embed in this value. For more information, see https://help.apple.com/instruments/developer/mac/current/#/devcd5016d31.

## Discussion

Discussion important: You don’t call this method directly. Instead, the framework calls it automatically when you append an interpolated object description to a log message.

## See Also

### Appending Objects

- [appendInterpolation(_:privacy:)](os/osloginterpolation/appendinterpolation(_:privacy:).md)