Re: [boost] Mother of all Variants

Am 27.06.19 um 04:03 schrieb David Sankel via Boost:

On Wed, Apr 17, 2019 at 8:42 AM Andrzej Krzemienski via Boost < boost@lists.boost.org> wrote:

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wt., 16 kwi 2019 o 23:57 Richard Hodges via Boost napisał(a):

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Are there real-world examples of well-designed classes who's move assignment operators throw?

I think if I saw that in a code review I'd be inclined to demand a different design choice.

Is there a good reason that variants should support such classes?

Some implementations of std::list throw from their move constructors and default constructors. I understand that the implementation is easier if even an empty list has a dummy node, which requires allocation.

Also classes that use the PIMPL idiom.

If a class uses PIMPL and does a move, isn't that just a pointer swap which cannot throw? Or would that be implemented as another allocation in the moved-from class? I can't imagine why.