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/// <typeparam name="TSender">The type of the source of the event.</typeparam>
/// <typeparam name="TEventArgs">The type of event data generated by the event.</typeparam>
/// <remarks>Type-safe variation from <see cref="EventHandler{TEventArgs}"/>.</remarks>
/// <inheritdoc cref="EventHandler{TEventArgs}"/>
[Serializable]
[SuppressMessage("Naming", "CA1711", Justification = "Type-safe event handler pattern")]
public delegate void TypeEventHandler<TSender, TEventArgs>(TSender sender, TEventArgs e);

/// <typeparam name="TSender">The type of the source of the event.</typeparam>
/// <remarks>Type-safe variation from <see cref="EventHandler"/>.</remarks>

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    public static bool IsInDirectory(this FileInfo file, DirectoryInfo directory) => file.Directory?.IsInDirectory(directory) ?? false;

    [SuppressMessage("Globalization", "CA1309", Justification = "Path comparison")]
    public static bool IsInDirectory(this DirectoryInfo path, DirectoryInfo directory)
        => path.Parent != null && (path.Parent.FullName.Equals(directory.FullName, StringComparison.InvariantCultureIgnoreCase) || path.Parent.IsInDirectory(directory));

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// This visitor implementation attemps to make the best of both worlds, between C#'s functional features and compile-time safety.
// Using extension methods as visitors makes it a runtime error for there not to be an equivalent visitor for every subclass of the element hierarchy.
// This approach ensures compile-time safety, while minimizing boilerplate. It's a step closer to the ideal of "if it compiles, it works".

using System;

Room room = new Bathroom(10);

RoomVisitor visitorPrintSurface = new(
    bathroom => Console.WriteLine($"Surface of bathroom: {bathroom.Surface}"),