Re: [Cython] [cython-users] C++: how to handle failures of 'new'?
Robert Bradshaw, 29.06.2012 11:08:
> On Thu, Jun 28, 2012 at 10:45 PM, Stefan Behnel wrote:
>> Robert Bradshaw, 28.06.2012 21:46:
>>> On Thu, Jun 28, 2012 at 11:38 AM, Stefan Behnel wrote:
>>>> currently, when I write "new CppClass()" in Cython, it generates a straight
>>>> call to the "new" operator. It doesn't do any error handling. And the
>>>> current documentation doesn't even mention this case.
>>>> Is there a "standard" way to handle this? It seems that C++ has different
>>>> ways to deal with failures here but raises an exception by default. Would
>>>> you declare the constructor(s) with an "except +MemoryError"? Is there a
>>>> reason Cython shouldn't be doing this automatically (if nothing else was
>>>> declared) ?
>>> I think it certainly makes sense to declare the default constructor as
>>> "except +" (and std::bad_alloc should become MemoryError),
>> Right. The code in the constructor can raise other exceptions that must
>> also be handled properly. An explicit "except +" will handle that.
>>> but whether
>>> to implicitly annotate declared constructors is less clear, especially
>>> as there's no way to un-annotate them.
>> I agree, but sadly, it's the default behaviour that is wrong. I'm sure we
>> made lots of users run into this trap already. I fixed the documentation
>> for now, but the bottom line is that we require users to take care of
>> proper declarations themselves. Otherwise, the code that we generate is
>> incorrect, although it's 100% certain that an allocation error can occur,