Performance test for swapping values with tuples and "old way". Tuples measure constantly better results

TuplesMeasure

import UIKit
import XCTest

class SwapOptimizedTests: XCTestCase {
    
    override func setUp() {
        super.setUp()
        // Put setup code here. This method is called before the invocation of each test method in the class.
    }
    
    override func tearDown() {
        // Put teardown code here. This method is called after the invocation of each test method in the class.
        super.tearDown()
    }
    
    func testExample() {
        // This is an example of a functional test case.
        XCTAssert(true, "Pass")
    }
    
    func testPerformanceTuplesWay() {
        self.measureBlock() {
            var a = "Marin"
            var b = "Todorov"
            for i in 1...1000000 {
                self.swapValues(&a, b: &b)
            }
        }
    }

    func testPerformanceOldWay() {
        self.measureBlock() {
            var a = "Marin"
            var b = "Todorov"
            for i in 1...1000000 {
                self.swapValuesOldWay(&a, b: &b)
            }
        }
    }

    func swapValues(inout a: String, inout b: String) {
        (a, b) = (b, a)
    }
    
    func swapValuesOldWay(inout a: String, inout b: String) {
        let c = a
        a = b
        b = c
    }
}