Getting the const-correctness of Object sorted once and for all

[Chris Cain]

On Tuesday, 15 May 2012 at 23:36:38 UTC, Chad J wrote:
> The idea /was/ to store the @instance variable with the object 
> specifically to avoid complex indirections.  Still have to 
> trust programmers though :/

But you /can't/ store the @instance variable with the object. As 
per the language reference, immutables may be stored in ROM. If 
the object is immutable (and const objects might be immutable), 
then the @instance variable would be stored in ROM, in which case 
it physically couldn't change no matter how hard you tried (or it 
would vomit run-time errors or some undefined behavior). The only 
"workable" solution would be an immutable pointer to the mutable 
variable.

Link: http://dlang.org/const3.html