swift 在Core Data中存储Swift值类型

Posted 2021-05-19

struct MyStruct {
    let x : Int
    let y : Bool
    let z : Double
}

let originalValue = MyStruct(x: 3, y: true, z: 1.3)

let data = valueToData(originalValue)

// Save data to CoreData

var s = MyStruct(x: 0, y: false, z: 0)  // Empty Value
dataToValue(&s, data: data) // Initialize with data

// s is MyStruct(x: 3, y: true, z: 1.3)

func valueToData<T>(var t: T) -> NSData {
    return NSData(bytes: &t, length: sizeof(T))
}

func dataToValue<T>(inout t: T, data: NSData) {
    memcpy(&t, data.bytes, data.length)
}