<!--
{
  "availability" : [
    "iOS: 18.0.0 -",
    "iPadOS: 18.0.0 -",
    "macCatalyst: 18.0.0 -",
    "macOS: 15.0.0 -",
    "tvOS: 18.0.0 -",
    "visionOS: 2.0.0 -",
    "watchOS: 11.0.0 -"
  ],
  "documentType" : "symbol",
  "framework" : "Accelerate",
  "identifier" : "/documentation/Accelerate/bnns_user_message_data_t",
  "metadataVersion" : "0.1.0",
  "role" : "Structure",
  "symbol" : {
    "kind" : "Structure",
    "modules" : [
      "Accelerate"
    ],
    "preciseIdentifier" : "c:@SA@bnns_user_message_data_t"
  },
  "title" : "bnns_user_message_data_t"
}
-->

# bnns_user_message_data_t

Additional user-defined logging argument for message-logging callbacks.

```
struct bnns_user_message_data_t
```

---

Copyright &copy; 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)