iPhone vs Android

[Laeeth Isharc via Digitalmars-d]

On Wednesday, 14 September 2016 at 06:33:59 UTC, Shachar Shemesh 
wrote:
> On 14/09/16 09:05, Walter Bright wrote:
>> On 9/13/2016 10:38 PM, Shachar Shemesh wrote:
>>> But if you do want to allow it, then my original problem 
>>> comes back.
>>> You have to
>>> scan the malloced memory because you are not sure where that 
>>> memory might
>>> contain pointers to GC managed memory.
>>
>> If mallocing for types that are statically known at compile 
>> time, it
>> should be knowable if they need scanning or not.
>>
>
> I believe you are under the assumption that structs will not be 
> GC allocated. I don't think it is a good assumption to make. 
> Even if it is, however:
>
> struct SomeStruct {
>   string something;
> }
>
> Please let me know if scanning this struct for GC pointers is 
> necessary or not. Also, even if this is knowable, I'm not sure 
> how you are suggesting we mange it.
>
> The only practical approach I see is that if any RC managed 
> memory might contain pointers to GC managed memory, then all RC 
> managed memory needs to be scanned (unless you think the 
> compiler can help out with that).
>
> Shachar

In D code that I have read where people use RC types they have 
different names making it quite clear - eg RCString.but

If you're worrying about GC presumably you have a decent size 
problem anyway (and I admire the ambition of weka in this 
respect).  So then seems to me that yes,  there is a tax in 
writing code that uses the language in a way that a minority of D 
users are using it in.   The generation after the pioneers, if 
they avoid the arrows of the prior generation, at least have a 
lot more hard work than subsequent generations.   But on the 
other hand it is a package deal, and initial costs amortise.

How would you end up with a GC allocated struct by mistake 
(presuming you think it through first) at the size you are at? 
200k lines and 30 people is a lot,  but it's also not Windows 
scale.   And if you did,  and it mattered,  wouldn't you pick it 
up quickly with GC profiling?