Consequences of casting away immutable from pointers

[jmh530]

On Friday, 5 January 2018 at 04:10:54 UTC, Steven Schveighoffer 
wrote:
>
> Yes, this is undefined behavior.
>
> https://dlang.org/spec/const3.html#removing_with_cast
>
> The compiler assumes x is going to be 5 forever, so instead of 
> loading the value at that address, it just loads 5 into a 
> register (or maybe it just folds x == 5 into true).
>
> The compiler would likely be free to assume *p_x == 5 forever 
> also, if it was clever enough.
>
> I'd recommend not doing this.
>
> -Steve

I also checked that if you create an instance of a class on the 
heap with an immutable constructor, then it's no longer in the 
register. Thus, I can now modify the immutable object from the 
pointer that I casted away immutable (though not that I would!)