Swift integer & byte array to ascii string convert performance test

bytes to string

func measure(closure: (()->Void)) {
    let start = Date()
    closure()
    let interval = Date().timeIntervalSince(start)
    print(interval)
}

extension Int {
    
    var ascii: [UInt8] {
        var array: [UInt8] = []
        var num = self
        
        repeat {
            array.append(UInt8(num%10 + 0x30))
            num = num/10
        } while num > 0
        
        return array.reversed()
    }
    
    var ascii2: [UInt8] {
        var array: [UInt8] = []
        var num = self
        
        repeat {
            array.insert(UInt8(num%10 + 0x30), at: 0)
            num = num/10
        } while num > 0
        
        return array
    }
}

measure {
    for _ in 0..<100 {
        let num = 123456789
        let asc = num.ascii
    }
}

measure {
    for _ in 0..<100 {
        let num = 123456789
        let asc = num.ascii2
    }
}

measure {
    
    for _ in 0..<100 {
        let num = 123456789
        let asc = "\(num)".data(using: .ascii)
    }
    
}

extension String {
    
    var ascii: [UInt8] {
        return unicodeScalars.map { return UInt8($0.value) }
    }
    
    var ascii2: [UInt8] {
        return [UInt8](self.data(using: .ascii)!)
    }
}

measure {
    
    for _ in 0..<2000 {
        let str = "asdfg 123 - qwe"
        let asci = str.ascii
    }
    
}

measure {
    
    for _ in 0..<2000 {
        let str = "asdfg 123 - qwe"
        let asci = str.ascii2
    }
    
}

let str = "asdfg 123 - qwe"
print(str.ascii == str.ascii2)