getting rid of immutable (or const)

[berni]

On Thursday, 5 September 2019 at 12:15:51 UTC, drug wrote:
> One solution could be using either pointer to `const(Point)` or 
> class here (to avoid pointer using) 
> https://run.dlang.io/is/rfKKAJ

OK. This are two solutions and although I'll probably not going 
to use any of those (due to other reasons), I still don't 
understand, why the original approach does not work. If I've got 
a book an put it in a box and later I'll get it out again, it's 
still the same book. So why has a struct changed when I put it 
into an AA and get it out again? It's not supposed to change...