[IronPython] Problem inheriting from C# abstract base class with overloaded constructors

[Dino Viehland]

This is bug #20021 - http://www.codeplex.com/IronPython/WorkItem/View.aspx?WorkItemId=20021

You should be able to declare the ctor public.  It shouldn't be an error to do that but you'll get an FxCop warning if you run FxCop.

I checked a fix for this in today into the Main branch (which is 2.1).  I think that should show up on CodePlex tonight or tomorrow if you're willing to build IronPython from source.  If not we'll definitely fix this in 2.0.1 if we don't spin a new build for 2.0 which would also likely include the fix.

> -----Original Message-----
> From: users-bounces at lists.ironpython.com [mailto:users-
> bounces at lists.ironpython.com] On Behalf Of Mark Traudt
> Sent: Wednesday, December 03, 2008 5:49 PM
> To: users at lists.ironpython.com
> Subject: [IronPython] Problem inheriting from C# abstract base class
> with overloaded constructors
>
>
> If I create an abstract base class in C# that has overloaded
> constructors,
> and then subclass from this in IronPython, then I am unable to call the
> non-default base class constructor from the __new__ method in the
> subclass.
> If I try, I get the result shown after the code sample.
>
> Interestingly, if I change the base class to not be abstract and to
> have
> public constructors (both changes are required) then my IronPython
> script
> works fine.
>
> Is this a bug?  If not, then am I doing something wrong, or is this not
> supported for some reason?
>
> I reproduced this with IronPython-1.1.2 and IronPython-2.0B5.
>
>
> *** OneOff.cs ***
>
> namespace Test
> {
>              public abstract class Foo
>         {
>                 protected Foo()
>                 {}
>
>                 protected Foo(int a)
>                 {
>                         a_ = a;
>                 }
>
>                 public override string ToString()
>                 {
>                         return "Foo: " + a_;
>                 }
>
>                 private int a_;
>         }
> }
>
>
> *** OneOff.py ***
>
> import clr
> clr.AddReferenceToFile("OneOff.dll")
> from Test import *
>
> class Bar(Foo):
>    def __new__ (cls, a=0):
>         return Foo.__new__(cls, a)
>
> print Bar()
> print Bar(42)
>
>
> *** Results ***
>
> Traceback (most recent call last):
>   File C:\dev\OneOff\IronPython\OneOff.py, line 10, in
>   File C:\dev\OneOff\IronPython\OneOff.py, line 8, in
>   File , line 0, in DefaultNew##15
> TypeError: default __new__ does not take parameters
>
>
> --
> View this message in context: http://www.nabble.com/Problem-inheriting-
> from-C--abstract-base-class-with-overloaded-constructors-
> tp20804327p20804327.html
> Sent from the IronPython mailing list archive at Nabble.com.
>
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