Constants, Aliases

[Lutger]

Hasan Aljudy wrote:
> 
> 
> Lutger wrote:
>> Alexander Panek wrote:
>>> Lutger wrote:
>>>> Xinok wrote:
>>>>> The problem with the const keyword is it doesn't guarantee the 
>>>>> expression will
>>>>> be constant.
>>>>
>>>> It doesn't? How can you modify a const var then? (in D)
>>>
>>> You can modify const variables that are not set directly at 
>>> declaration (write-once constants) just by getting their address and 
>>> modifying them through another variable/pointer.
>>
>> Haha yes it works. Is that how it should be or is it a bug or compiler 
>> limitation? It looks whacky to me. You can only write a const once in 
>> a constructor or so says DMD, thus it seems like this subverts the 
>> system in more than one way. I can't imagine that ever being useful.
> 
> Why not?
> It's useful when you work with sane programmers.
> 
> After all, with pointers and asm, there's no limit to how many things 
> you can mess.

Sure, if you want it you can break the type system. But there are some 
barriers for pointers, these are still typed. I don't think it is so 
obscure.
If you have a const value type in a class, you must set it in the 
initializer or the constructor. You also cannot modify it. Fine, but 
then if you have a getter return a reference to it, suddenly all bets 
are off.
This is not what I'd expect, probably because of a C++ bias I still have 
somewhere, that I (wrongly) think const is part of the type system?