C++ adjusts vtable pointers when calling ctors and dtors. Why doesn't Swift do vtable adjustment when calling deinit?
Asked on 05/05/2025
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In Swift, the deinitialization process does not involve vtable adjustments like in C++ because Swift's memory management and object model are designed differently. Swift uses Automatic Reference Counting (ARC) to manage the lifecycle of objects, which simplifies the deinitialization process. The deinitializer (deinit) in Swift is called automatically when an object's reference count drops to zero, and there is no need for vtable adjustments because Swift does not use a vtable for method dispatch in the same way C++ does.
Swift's approach to memory management and function dispatch is more static and relies on compile-time information as much as possible, which can lead to more efficient code execution. This is discussed in the session Explore Swift performance at WWDC 2024, where the differences in function calls and memory management between Swift and other languages like C++ are explored.
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