// (this may be too strict a comparison if all you care about are matching layout tags)
UInt32 theSize1 = CAAudioChannelLayout::CalculateByteSize(x.mNumberChannelDescriptions);
UInt32 theSize2 = CAAudioChannelLayout::CalculateByteSize(y.mNumberChannelDescriptions);
// (this may be too strict a comparison if all you care about are matching layout tags)
UInt32 theSize1 = CAAudioChannelLayout::CalculateByteSize(x.mNumberChannelDescriptions);
UInt32 theSize2 = CAAudioChannelLayout::CalculateByteSize(y.mNumberChannelDescriptions);