using System;

​

using System.Runtime.CompilerServices;

using System.Runtime.InteropServices;

​

​

public class Program

{

    public static void Main()

    {

​

        var value = "Hello";

        Console.WriteLine(value);

​

        // Manual

        ulong longManual = (ulong)value[3] << 48 | (ulong)value[2] << 32 | (ulong)value[1] << 16 | (ulong)value[0];

        Console.WriteLine("Manual:    " + longManual);

​

        // Naive allocating way

        var valueArray = value.ToCharArray();

        var longArray = MemoryMarshal.Cast<char, ulong>(valueArray);

        Console.WriteLine("Control:   " + longArray[0]);

​

        // Optimized

        var longVal = Unsafe.As<char, ulong>(ref Unsafe.AsRef(value.GetPinnableReference()));

        Console.WriteLine("Optimized: " + longVal);

​

    }

}