Generalized accessors

1. subscrit get set
2. get let nums = Array(0..<10) let x10 = nums[3] * 10 // `get` print(num) subscript(index: Int) -> Element { get { let element = // `index` return element // } set { ... } }
3. set var nums = Array(0..<10) let num = nums[3] nums[3] = num * 10 // `set` print(num) subscript(index: Int) -> Element { get { ... } set(newValue) { // `newValue` // buffer = newValue } }
4. Swift 4.2 mutableAddressWithPinnedNativeOwner Swift 5 read , modify yield co-routine
5. read // CoreAudio.swift subscript(index: Index) -> Element { _read { yield ((_audioBuffersPointer + index).pointee) } } modify // Array.swift subscript(index: Int) -> Element { _modify { let address = _buffer.subscriptBaseAddress + index yield &address.pointee } }
6. yield subscript(index: Int) -> inout Element {} inout Rust Lifetime Rust Swift
7. yield
8. !