The "no gc" crowd

[Andrei Alexandrescu]

On 10/10/13 12:18 AM, Walter Bright wrote:
> On 10/9/2013 11:34 PM, Jacob Carlborg wrote:
>> On 2013-10-10 02:22, Sean Kelly wrote:
>>
>>> Only that this would have to be communicated to the user, since
>>> moving data
>>> later is problematic. Today, I think it's common to construct an
>>> object as
>>> unshared and then cast it.
>>
>> What is the reason to not create it as "shared" in the first place?
>
> 1. Shared data cannot be passed to regular functions.

I don't understand this. If a function/method accepts "shared", then it 
can be passed shared data.

> 2. Functions that create data structures would have to know in advance
> that they'll be creating a shared object. I'm not so sure this would not
> be an invasive change.

There is no other way around it. And this is not a change - it's fixing 
something.

> 3. Immutable data is implicitly shared. But it is not created immutable
> - it is created as mutable data, then set to some state, then cast to
> immutable.

That all must happen in the runtime, NOT in user code.


Andrei