DIP60: @nogc attribute

[Walter Bright via Digitalmars-d]

On 4/17/2014 12:41 PM, Steven Schveighoffer wrote:
> On Thu, 17 Apr 2014 14:47:00 -0400, Walter Bright <newshound2 at digitalmars.com>
> wrote:
>
>> On 4/17/2014 10:05 AM, Steven Schveighoffer wrote:
>>>> Obj-C only uses ARC for a minority of the objects.
>>> Really? Every Obj-C API I've seen uses Objective-C objects, which all use RC.
>>
>> And what about all allocated items?
>
> What do you mean?

Can you call malloc() ?

>>>> A UI is a good use case for ARC. A UI doesn't require high performance.
>>> I've written video processing/players on iOS, they all use blocks and reference
>>> counting, including to do date/time processing per frame. All while using RC
>>> network buffers. And it works quite smoothly.
>>
>> And did you use ref counting for all allocations and all pointers?
>
> Yes.

You never used malloc? for anything? or stack allocated anything? or had any 
pointers to anything that weren't ref counted?

How did that work for printf?


>> There's no doubt that ref counting can be used successfully here and there,
>> with a competent programmer knowing when he can just convert it to a raw
>> pointer and use that.
>
> The compiler treats pointers to NSObject-derived differently than pointers to
> structs and raw bytes.

So there *are* regular pointers.

> There is no need to know, you just use them like normal
> pointers, and the compiler inserts the retain/release calls for you.

I know that with ARC the compiler inserts the code for you. That doesn't make it 
costless.


> But I did not use structs. I only used structs for network packet overlays. I
> still created an object that contained the struct to enjoy the benefits of the
> memory management system.
>
>> And remember that if you have exceptions, then all the dec code needs to be in
>> exception unwind handlers.
>
> I haven't really used exceptions, but they automatically handle the reference
> counting.

I know it's done automatically. But you might be horrified at what the generated 
code looks like.