'final' variables

[Andrei Alexandrescu (See Website For Email)]

Lionello Lunesu wrote:
> Andrei Alexandrescu (See Website For Email) wrote:
>> Lionello Lunesu wrote:
>>> I've been trying to follow the thread on the const/final/invariant 
>>> extensions but I have to wonder: how useful are final variables?
>>>
>>> final int i = 2;
>>>
>>> This would mean: 'i' cannot be rebound to another value. Right? So 
>>> this final is actually C++'s const.
>>>
>>> void func( final int i )
>>> {
>>>   //i is not const but cannot be set either
>>> }
>>>
>>> Also here, it's like C++'s const, but with the _removed_ benefit of 
>>> restricting the accepted types. Is this correct?
>>>
>>> What's the use of "final" for variables? I'm saying "for variables" 
>>> because for methods the benefit is only too clear.
>>>
>>> L.
>>>
>>> PS. I've started a new thread because this isn't a reply to any 
>>> particular post.
>>
>> Very simple.
>>
>> void Fun(const char[] s)
>> {
>>   ...
>> }
>>
>> Cannot modify s's content, but can rebind it. If the programmer wants 
>> to not rebind, then she writes:
>>
>> void Fun(final const char[] s)
>> {
>>   ...
>> }
> 
> I understand, but what's the point of telling the compiler "I don't want 
> to rebind this variable"? It doesn't seem like an optimization hint. 
> Like telling "func(const int i)" in C++ doesn't actually do anything. 
> You just type more. And if you later want to rebind 'i' you'll have to 
> change the interface. Lose-lose?

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Andrei