Nikita Nemkin, 07.06.2013 13:24:
> Currently, conditional casts like <Name?>obj do not allow None values.
This might seem like an inconsistency, because <Name>obj does allow None
values, just like a normal assignment. However, it's a special case that
asks explicitly for the given type, so I think it's ok to be stricter.
> I have found it useful to allow None sometimes.
> The syntax could be one of:
> * <Name or None?>obj
> * <Name? or None>obj
> * <Name??>obj
>
> Use case (without this feature):
>
> tn_obj = self.any.non_trivial.nullable.expression()
> cdef TypeName tn
> if tn_obj is not None:
> tn = <TypeName?>tn_obj
> ...
>
> Use case (with this feature):
>
> cdef TypeName tn = <TypeName or
> None?>self.any.non_trivial.nullable.expression()
> if tn is not None:
> ...
Why not just
cdef TypeName tn = self.any.non_trivial.nullable.expression()
if tn is not None:
...
?
I.e. why do you need that cast in the first place?
Stefan
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