new constraint in generics

[Alex Shirshov]

Hi all!

How can i specify, that the generic class have the constructor?
With c# it's a new constraint.

For instance, i write

Class cls1(Of T)
Public Sub some()
Dim tt As New T() ' here is an error: 'New' cannot be used on a
type parameter not declared 'As New()'.
End Sub
End Class

Ok. Next try

Class cls1(Of T as New()) ' another error: Keyword does not name a type.
Public Sub some()
Dim tt As New T() 'previos error still here
End Sub
End Class

Now i have two error message!

Can anyone help?

P.S. My versions is VS.NET Whidbey 8.0.30703.4. and the .NET Framework
1.2.30703

 

[Herfried K. Wagner [MVP]]

How can i specify, that the generic class have the constructor?
With c# it's a new constraint.

I would suggest to post the question to one of the Longhorn communities:

<http://longhorn.msdn.microsoft.com/lhsdk/port_communities.aspx>

 

[Mattias Sjögren]

Alex,

How can i specify, that the generic class have the constructor?

This didn't work in the PDC alpha release, but I believe it will in a
future beta release.



Mattias

 

[Herfried K. Wagner [MVP]]

Errata:

I feel sorry for posting the wrong link...

<http://communities.microsoft.com/newsgroups/default.asp?icp=whidbey&slcid=us>