[ITK-dev] Workaround for dynamic_cast on Mac OSX

[Marcus D. Hanwell]

On Tue, Nov 8, 2016 at 5:01 PM, Matt McCormick
<matt.mccormick at kitware.com> wrote:
> Hi folks,
>
> As we have wrestled with in Slicer, along with other applications
> where ITK is used in multiple shared libraries, dynamic_cast can fail
> on Mac OSX.
>
> I summarized the cause of the problem and steps for the proposed solution here:
>
>   https://issues.itk.org/jira/browse/ITK-3490
>
> Feedback is welcome. The effort is targeted for the ITK 4.11.0 release.
>
>From the issue it is not clear to me why you can't fix the symbol
visibility issues, or which of these cases it causing the breakage.
Reading the linked blog post it seems like Apple/Clang is doing the
right thing, and C++ libraries must be careful to use consistent
symbol visibility.

I would be interested in further details on which case or cases are
causing dynamic_cast to fail, and why using consistent symbol
visibility in the interfaces is not feasible/possible.

Thanks,

Marcus