Функция, возвращающая массив структуры. Как?

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Private Structure str1
  Dim a As Byte
  Dim b As Byte
End Structure
 
Private Function aaaa(ByVal aa As Byte) As str1
  If aa = 1 Then aaaa.a = 1 : aaaa.b = 2
End Function
 
MsgBox(aaaa(1).a)
'------------------------------------

MsgBox(aaaa(1).a)

MsgBox(aaaa(1)(0).a)

    Private Structure str1
        Dim a As Byte
        Dim b As Byte
    End Structure
    Private Function aaaa(ByVal n As Integer, ByVal aa As Byte) As str1()
        Dim ccc(n) As str1
        Select Case aa
            Case 1 : ccc(0).a = 1 : ccc(0).b = 2
            Case 2 : ccc(1).a = 3 : ccc(1).b = 4
            Case 3 : ccc(2).a = 5 : ccc(2).b = 6
        End Select
        Return ccc
    End Function
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim b(2) As str1
        b = aaaa(b.Length - 1, 2)
 
    End Sub

Dim aaaa(5)() As str1

'------------------------------------------------------
Private Structure str1
  Dim a As Byte
  Dim b As Byte
End Structure
 
Private Function aaaa(ByVal aa As Byte) As Array
  Dim ccc(2) As str1
 
  ccc(0).a = 1
  ccc(1).a = 2
  ccc(2).a = 3
   
  Return ccc
End Function
 
Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
  
  Dim ddd() As str1 = aaaa(1)
 
  MsgBox(ddd(0).a)
  MsgBox(ddd(1).a)
  MsgBox(ddd(2).a)
End Sub
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