[PyKDE] Re: PyKDE Digest, Vol 6, Issue 5

[Gerard Vermeulen]

On Tue, 11 Jan 2005 10:44:40 -0000 (GMT)
"Phil Thompson" <phil at riverbankcomputing.co.uk> wrote:

> > It looks like a clarification of C++ is in order.
> >>>
> >>> I would expect that one can pass a Python int as well as a SIP-4.2
> >>> enum
> >>> argument into an enum parameter of a function wrapped by SIP (a C++
> >>> function with a C++ enum parameter accepts C++ int arguments).
> >
> > That is incorrect.  C++ will NOT accept an int when a function has an
> > enum parameter.  However, if the function takes an int it WILL allow an
> > enum.  This is because C++ will convert and enum into an int, but not
> > an int into an enum.  This is part of its type safety features.
> >
> >
> >> Ok, I've had second thoughts about this - the idiom of oring enum
> >> values is
> >> too common. Tonight's SIP snapshot will allow an integer whereever an
> >> enum is
> >> expected. I can still get QListBox.setColumnMode() to work properly,
> >> which
> >> was the original intent of the change.
> >>
> > The 'or'ing together of enums to form an argument to a function is
> > common, but if you look, the function signature takes an 'int' and not
> > the enum.  When this is done, the enum is just being used as a symbolic
> > constant and its type is usually irrelevant.
> 
> Ok, I've now had third thoughts about this after realising that the
> exceptions I was seeing with the strict checking were bugs in the examples
> I was using, and not related to the oring of enums. Strict checking will
> go back into the next snapshot.
> 
> There will be a SIP v4.2rc1 before the final release of v4.2 to give
> people a final opportunity to change my mind (again).
> 
Fine with me, I goofed with respect to the conversions between enum and int.

Gerard