Logical const

[Bruno Medeiros]

On 03/12/2010 01:38, Walter Bright wrote:
> Steven Schveighoffer wrote:
>> On Thu, 02 Dec 2010 13:57:04 -0500, Bruno Medeiros
>> <brunodomedeiros+spam at com.gmail> wrote:
>>
>>> On 29/11/2010 14:56, Steven Schveighoffer wrote:
>>>> This has been discussed at length on this newsgroup, and I argued
>>>> for it
>>>> for a long time. You will not get any traction with Walter, because
>>>> I've already proven that logical const == const, and it still doesn't
>>>> change his mind.
>>>
>>> Could you detail a bit what do you mean by logical const == const ?
>>> That doesn't sound right to me.
>>>
>>
>> Here is where I show how logical const already exists, it's just
>> clunky to use.
>>
>> BTW, this was before TLS, so the example would have to be updated a bit.
>>
>> http://www.digitalmars.com/webnews/newsgroups.php?art_group=digitalmars.D&article_id=58927
>
>
> What you're doing is keeping an alternate, mutable reference to each
> object. This does not mean that logical const == const.

The statement "logical const == const" is meaningless really. Please use 
better terms people. ~_~'

What Steven was trying to say, I think, is that you can always emulate 
the behavior of logical const in D in a valid (safe) way, and that 
therefore the current D const system doesn't actually offer more 
guarantees than having logical const (by this I mean having mutable 
members).

Whether this is true or not, that's the question. I don't think it is 
true, I've argued that in a reply to the previous post. Note that the 
other extreme, which you mentioned: "Having mutable members destroys any 
guarantees that const provides. ", is also not true. (again, argued in 
another post).

-- 
Bruno Medeiros - Software Engineer