Swift通用逻辑

• Metadata
  • TargetMetadata
    • TargetValueMetadata = ValueMetadata
      • [-0x8] => VWT=ValueWitnessTable
    • TargetClassMetadata = ClassMetadata
  • HeapMetadata
• 其他相关
  • Protocol
    • PWT=Protocol Witness Table = ProtocolWitnessTable
    • ValueBuffer
  • Exitential Container?
    • Box?
  • Opaque ?