Swift access to variable length array

Question

Core Audio has a C API that copies some data into memory you supply. In one case, I need to pass in a pointer to an AudioBufferList, which is defined as:

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Answer 1

You can create a buffer pointer that starts at the given address and has the given number of elements:

let buffers = UnsafeBufferPointer<AudioBuffer>(start: &bufferList.memory.mBuffers,
    count: Int(bufferList.memory.mNumberBuffers))

for buf in buffers {
    // ...
}

Update for Swift 3 (and later):

let buffers = UnsafeBufferPointer<AudioBuffer>(start: &bufferList.pointee.mBuffers,
    count: Int(bufferList.pointee.mNumberBuffers))

for buf in buffers {
    // ...
}