Public Function CheckType(Of T)(ByVal arg As T) As System.Type
   Return GetType(T)
End Function

Public Function IsNullable(Of T)(ByVal arg As T) As Boolean
   Return Nullable.GetUnderlyingType(GetType(T)) IsNot Nothing
End Function

Sub Main()
        Dim test0 As Integer = 0
        Dim test1? As Integer = 1
        Dim test2 As Integer? = 2
        Dim test3 As Nullable(Of Integer) = 3

        Dim test4 As Boolean = False
        Dim test5 As Nullable(Of Boolean) = Nothing

        Dim test6 As DateTime = DateTime.Now()
        Dim test7 As Nullable(Of DateTime) = Nothing

        Console.WriteLine(CheckType(test0).ToString() & " - IsNullable: " & IsNullable(test0))
        Console.WriteLine(CheckType(test1).ToString() & " - IsNullable: " & IsNullable(test1))
        Console.WriteLine(CheckType(test2).ToString() & " - IsNullable: " & IsNullable(test2))
        Console.WriteLine(CheckType(test3).ToString() & " - IsNullable: " & IsNullable(test3))
        Console.WriteLine(CheckType(test4).ToString() & " - IsNullable: " & IsNullable(test4))
        Console.WriteLine(CheckType(test5).ToString() & " - IsNullable: " & IsNullable(test5))
        Console.WriteLine(CheckType(test6).ToString() & " - IsNullable: " & IsNullable(test6))
        Console.WriteLine(CheckType(test7).ToString() & " - IsNullable: " & IsNullable(test7))

        Console.WriteLine("Premi un tasto per chiudere...")
        Console.ReadKey()
    End Sub