The Status of Const

[Steven Schveighoffer]

On Thu, 12 Aug 2010 22:09:51 -0400, Michel Fortin  
<michel.fortin at michelf.com> wrote:

> On 2010-08-12 18:56:50 -0400, dsimcha <dsimcha at yahoo.com> said:
>
>> How can these limitations be worked around and/or fixed?
>
> Unsatisfaction about Rebindable seems pretty generalized.
>
> Here's an idea for a solution. Basically the problem is only in the  
> syntax, where the reference is implicitly part of the object's type and  
> thus impossible to put outside from the type modifier. An easy solution  
> would be to add an explicit reference marker, but this would change the  
> syntax for existing code, and I have to admit the current syntax is nice  
> (up until you try to add a modifier). But we could make the reference  
> marker optional, like this:
>
> 	Object o; // implicitly a reference
> 	Object ref o; // explicit reference marker
>
> Both would be allowed and equivalent. While the first form is nicer to  
> the eye, the second makes it easy to apply a type modifier while  
> excluding the reference:
>
> 	const(Object)ref o;
> 	shared(Object)ref o;

I really really like this idea.  I remember seeing a suggestion like this  
a long time ago, but I think it was ref const(Object).  That is ambiguous  
because you could have a ref to an object ref.  With your idea, I think  
this would be ref const(Object) ref (a little ugly, but no worse than  
const const(Object) fn()).

I like how it reads naturally.  I think it's also syntactically  
unambiguous.  Walter, please give this one some attention, I'd love to see  
this fixed.

-Steve