Demo showed in my video https://youtu.be/KAXuZ9pGB4w

StaticStringConversation.swift

import Foundation

func benchmarkStringConversion() {
    let dynamicString: String = "This is a string"
    let iterations = 100_000
    var dynamicResult = 0

    let startDynamic = CFAbsoluteTimeGetCurrent()
    for _ in 0..<iterations {
        let utf8Data = Array(dynamicString.utf8)
        dynamicResult += utf8Data.count
    }
    let endDynamic = CFAbsoluteTimeGetCurrent()
    print("String time: \(endDynamic - startDynamic) seconds. Result: \(dynamicResult)")
}

func benchmarkStaticStringConversion() {
    let staticString: StaticString = "This is a string"
    let iterations = 100_000
    var staticResult = 0

    let startStatic = CFAbsoluteTimeGetCurrent()
    for _ in 0..<iterations {
        let utf8Pointer = staticString.utf8Start
        let count = staticString.utf8CodeUnitCount
        staticResult += count
    }
    let endStatic = CFAbsoluteTimeGetCurrent()
    print("StaticString time: \(endStatic - startStatic) seconds. Result: \(staticResult)")
}

func run() async {
    print("Starting benchmarks in parallel...")
    
    await withTaskGroup(of: Void.self) { taskGroup in
        taskGroup.addTask {
            benchmarkStringConversion()
        }
        taskGroup.addTask {
            benchmarkStaticStringConversion()
        }
    }
    
    print("Benchmarks completed!")
}

// Wrap the async call in a Task when run in playground.
Task {
    await run()
}

/*
 String UTF-8 Conversion:

 dynamicString converts to an array of UTF-8 bytes (Array(dynamicString.utf8)).
 This operation adds significant overhead to String.

 StaticString accesses its UTF-8 data directly via the utf8Start pointer.
 No dynamic memory allocation is required, which demonstrates StaticString's efficiency.
 */