Re: Mother of all Variants

From: Gavin Lambert (boost_at_[hidden])
Date: 2019-06-27 07:50:03

On 27/06/2019 19:40, degski wrote:
> I'm just reading (https://en.cppreference.com/w/cpp/container/list/list):
> "After container move construction (overload (6)), references, pointers,
> and iterators (other than the end iterator) to other remain valid, but
> refer to elements that are now in *this. The current standard makes this
> guarantee via the blanket statement in
> §23.2.1[container.requirements.general]/12, and a more direct guarantee is
> under consideration via LWG 2321
> <http://www.open-std.org/JTC1/SC22/WG21/docs/lwg-active.html#2321>."
> 
> Possibly I'm reading it wrongly, please set me right in that case. LWG 2321
> <http://www.open-std.org/JTC1/SC22/WG21/docs/lwg-active.html#2321> goes on
> about std::swap as well.

Hmm.  I read that the same way too.  I wonder how that works with 
checked/debug/safe iterators that contain a reference to the container 
that they were from -- presumably after a swap they're now pointing at 
the second container's elements, but still have a reference to the first 
container?  Unless it can somehow swap what container all the iterators 
point at too, without touching each one individually.