DIP53 and DIP49 (ver2) - New definitions for qualified constructors and postblits

[ilya-stromberg]

On Thursday, 19 December 2013 at 11:22:59 UTC, Maxim Fomin wrote:
> On Thursday, 19 December 2013 at 07:31:28 UTC, ilya-stromberg 
> wrote:
>> What should we do if we decide that we need REAL `const` 
>> postblit/constructor? I mean postblit/constructor that creates 
>> only `const` object that can't be implicitly converted to the 
>> `mutable` or `immutable`.
>
> D is not C/C++. Objects are either mutable or immutable. 
> Sometimes you can view any of them through const. There are no 
> const objects per se.

Yes, I know. The `const` type means that I don't know at compile 
time real object type: it can be `mutable` or `immutable` type.
I can use `const` postblit/constructor to mark object. It lets me 
know the real object type at the run time and provide additional 
optimisations. So, it's a kind of dynamic typing.
See also example here:
http://forum.dlang.org/thread/oijzbufgajagkonenmxp@forum.dlang.org?page=5#post-pakelxyollnwvewuxajo:40forum.dlang.org