dispatch test.swift

import XCTest

final class Static {
    func a() { 1 + 1 }
    func b() { a() }
    func c() { b() }
}

class Dynamic {
    func a() { 1 + 1 }
    func b() { a() }
    func c() { b() }
}

class Dynamic1: Dynamic { }

class Dynamic2: Dynamic1 { }

class Dynamic3: Dynamic2 {
    override func a() { 1 + 1 }
    override func b() { a() }
    override func c() { b() }
}

class MyTestCase: XCTestCase {
    func testStatic() {
        let s = Static()
        measure {
            for _ in 0..<10000 {
                s.c()
            }
        }
    }

    func testDynamic() {
        let d: Dynamic
        d = Dynamic3()
        measure {
            for _ in 0..<10000 {
                d.c()
            }
        }
    }
}

MyTestCase.defaultTestSuite.run() // Swift 4