const as default for variables

[Zach the Mystic via Digitalmars-d]

On Tuesday, 17 March 2015 at 19:53:14 UTC, deadalnix wrote:
> On Tuesday, 17 March 2015 at 13:55:36 UTC, Dejan Lekic wrote:
>> I definitely think this is a good idea. And if someone wants 
>> mutable variable, we simply use proposed 'var' storage class.
>>
>> Brilliant!
>
> This is going to break pretty much all the code that use auto.
>
> The benefice for the compiler is hypothetical. Walter is right 
> when mentioning that is can remove some refcount boilerplate, 
> which is right but, we have no idea how much, and how good the 
> compiler would be at recognizing them. With existing languag 
> feature, the compiler CANNOT leverage this change for 
> optimization.

The real devil against safe reference counting is in the 
assignment operators, when they do destructive moves. I think 
those have to be the focus of any effort here.

I'm trying to imagine a parameter attribute `@destroy`, for 
example, indicating that its reference may get destroyed. Not 
sure if it will work, or even help, but it's a start.