# UnsafeMutableMIDIPacketListPointer ``` struct UnsafeMutableMIDIPacketListPointer ``` ## Topics ### Initializers [`init(UnsafeMutablePointer, byteSize: Int)`](/documentation/CoreMIDI/UnsafeMutableMIDIPacketListPointer/init(_:byteSize:)-8acwt) [`init?(UnsafeMutablePointer?, byteSize: Int)`](/documentation/CoreMIDI/UnsafeMutableMIDIPacketListPointer/init(_:byteSize:)-96k5n) ### Instance Properties [`var count: Int`](/documentation/CoreMIDI/UnsafeMutableMIDIPacketListPointer/count) [`var lastPacket: UnsafeMutablePointer?`](/documentation/CoreMIDI/UnsafeMutableMIDIPacketListPointer/lastPacket) [`var listSizeInBytes: Int`](/documentation/CoreMIDI/UnsafeMutableMIDIPacketListPointer/listSizeInBytes) ### Instance Methods [`func append(timestamp: MIDITimeStamp, data: [UInt8]) -> UnsafePointer?`](/documentation/CoreMIDI/UnsafeMutableMIDIPacketListPointer/append(timestamp:data:)) [`func clear()`](/documentation/CoreMIDI/UnsafeMutableMIDIPacketListPointer/clear()) ## Relationships ### Conforms To [`Sequence`](/documentation/Swift/Sequence) --- Copyright © 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)