interface制約は個別にインターフェースを指定してます。
構文
interface制約
Public Class クラス名(Of t As インターフェース名)
End Class
Public Class Form1
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Dim ic As New interfaceclass(Of iclass)
End Sub
End Class
Public Class interfaceclass(Of t As Sinterface)
End Class
Public Interface Sinterface
End Interface
Public Class iclass
Implements Sinterface
End Class