Imports System

Friend Class InternalOnly
    Public Class Nested
    End Class
End Class

Public Class Example
    Public Class Nested
    End Class

    Public Shared Sub Main()
        With GetType(InternalOnly.Nested)
            Console.WriteLine("Is the " & .FullName _ 
                & " class visible outside the assembly? " & .IsVisible)
        End With

        With GetType(Example.Nested)
            Console.WriteLine("Is the " & .FullName _ 
                & " class visible outside the assembly? " & .IsVisible)
        End With
    End Sub
End Class

' This example produces the following output:
'
'Is the InternalOnly+Nested class visible outside the assembly? False
'Is the Example+Nested class visible outside the assembly? True

using System;

internal class InternalOnly 
{
    public class Nested {}
}

public class Example
{
    public class Nested {}

    public static void Main()
    {
        Type t = typeof(InternalOnly.Nested);
        Console.WriteLine(
            "Is the {0} class visible outside the assembly? {1}", 
            t.FullName, 
            t.IsVisible
        );

        t = typeof(Example.Nested);
        Console.WriteLine(
            "Is the {0} class visible outside the assembly? {1}", 
            t.FullName, 
            t.IsVisible
        );
    }
}

/* This example produces the following output:

Is the InternalOnly+Nested class visible outside the assembly? False
Is the Example+Nested class visible outside the assembly? True
 */

using namespace System;

private ref class InternalOnly 
{
public:
    ref class Nested {};
};

public ref class Example 
{
public:
    ref class Nested {};
}; 


// Entry point of example
int main()
{
    Type^ classType = InternalOnly::Nested::typeid;
    Console::WriteLine(
        "Is the {0} class visible outside the assembly? {1}",
        classType->FullName, classType->IsVisible);

    classType = Example::Nested::typeid;
    Console::WriteLine(
        "Is the {0} class visible outside the assembly? {1}", 
        classType->FullName, classType->IsVisible);
}

/* This example produces the following output:

Is the InternalOnly+Nested class visible outside the assembly? False
Is the Example+Nested class visible outside the assembly? True
*/