<!--
{
  "availability" : [
    "iOS: 17.0.0 -",
    "iPadOS: 17.0.0 -",
    "macCatalyst: 17.0.0 -",
    "macOS: 14.0.0 -",
    "tvOS: 17.0.0 -",
    "visionOS: 1.0.0 -",
    "watchOS: 10.0.0 -"
  ],
  "documentType" : "symbol",
  "framework" : "CoreMedia",
  "identifier" : "/documentation/CoreMedia/CMTagCollectionCreateMutableCopy",
  "metadataVersion" : "0.1.0",
  "role" : "Function",
  "symbol" : {
    "kind" : "Function",
    "modules" : [
      "Core Media"
    ],
    "preciseIdentifier" : "c:@F@CMTagCollectionCreateMutableCopy"
  },
  "title" : "CMTagCollectionCreateMutableCopy"
}
-->

# CMTagCollectionCreateMutableCopy

Creates a new mutable copy from an existing tag collection.

```
extern OSStatus CMTagCollectionCreateMutableCopy(CMTagCollectionRef tagCollection, CFAllocatorRef allocator, CMMutableTagCollectionRef*newMutableCollectionCopyOut);
```

## Parameters

`tagCollection`

The tag collection to copy.

`allocator`

The allocator to use for the new tag collection. Pass `kCFAllocatorDefault` to use the default global allocator.

`newMutableCollectionCopyOut`

The output destination for the new mutable tag collection.

## Return Value

Returns `0` on success and a value from Tag Collection Error Codes on failure.

---

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)