iOS: Compare class and struct timing

ClassStructTiming.swift

//
// ClassStructTiming.swift
//
// Compare class and struct timing
//
// Derived from https://github.com/knguyen2708/StructVsClassPerformance

import Foundation

class IntClass {
    var value: Int
    init(_ val: Int) { self.value = val }
}

struct IntStruct {
    var value: Int
    init(_ val: Int) { self.value = val }
}

func + (x: IntClass, y: IntClass) -> IntClass {
    return IntClass(x.value + y.value)
}

func + (x: IntStruct, y: IntStruct) -> IntStruct {
    return IntStruct(x.value + y.value)
}

// 10 fields
class Int10Class {
    var value1, value2, value3, value4, value5, value6, value7, value8, value9, value10: Int
    
    init(_ val: Int) {
        self.value1 = val
        self.value2 = val
        self.value3 = val
        self.value4 = val
        self.value5 = val
        self.value6 = val
        self.value7 = val
        self.value8 = val
        self.value9 = val
        self.value10 = val
    }
}

struct Int10Struct {
    var value1, value2, value3, value4, value5, value6, value7, value8, value9, value10: Int
    
    init(_ val: Int) {
        self.value1 = val
        self.value2 = val
        self.value3 = val
        self.value4 = val
        self.value5 = val
        self.value6 = val
        self.value7 = val
        self.value8 = val
        self.value9 = val
        self.value10 = val
    }
}

func + (x: Int10Struct, y: Int10Struct) -> Int10Struct {
    return Int10Struct(x.value1 + y.value1)
}

func + (x: Int10Class, y: Int10Class) -> Int10Class {
    return Int10Class(x.value1 + y.value1)
}

func measure(_ name: String, block: () -> ()) -> Double {
    
    let t0 = Date()
    
    block()
    
    let ft = Date().timeIntervalSince(t0)
    
    print("\(name) -> \(ft)")
    
    return ft
}

func runTests() {
    let c1t = measure("class (1 field)") {
        var x = IntClass(0)
        for _ in 1...10000000 {
            x = x + IntClass(1)
        }
    }
    
    let s1t = measure("struct (1 field)") {
        var x = IntStruct(0)
        for _ in 1...10000000 {
            x = x + IntStruct(1)
        }
    }
    
    let ratio1 = c1t / s1t
    
    print("class/struct = \(ratio1)")
    
    let c10t = measure("class (10 fields)") {
        var x = Int10Class(0)
        for _ in 1...10000000 {
            x = x + Int10Class(1)
        }
    }
    
    let s10t = measure("struct (10 fields)") {
        var x = Int10Struct(0)
        for _ in 1...10000000 {
            x = x + Int10Struct(1)
        }
    }
    
    let ratio10 = c10t / s10t
    
    print("class/struct = \(ratio10)")
}

runTests()