Why does it segfault? Because you have not used a sufficiently clever value for the integer that wouldn't when used as an address?

Just wondering.

Realistically that would be quite rare since it is obvious that this is unprotected shared mutable access. But interesting that such a conversion without unsafe may happen. If it segfaults all the time though then we still have memory safety I guess.

The article is interesting but I wish it would try to provide ideas for solutions then.