Disadvantages of ARC

[Andrei Alexandrescu]

On 2/6/14, 9:19 AM, H. S. Teoh wrote:
> On Thu, Feb 06, 2014 at 04:30:31PM +0000, Dicebot wrote:
>> On Thursday, 6 February 2014 at 16:25:37 UTC, Andrei Alexandrescu
>> wrote:
>>> // lib code
>>> struct RCSlice(T) { ... }
>>> alias rcstring = RCSlice!(immutable char);
>>> rcstring rc!(string s) { ... }
>>>
>>> // user code
>>> auto s1 = buildPath!("hello", "world");
>>> auto s2 = buildPath!(rc!"hello", rc!"world");
>>>
>>> In this example s1 will have type string and s2 will have type
>>> rcstring.
>>
>> Looks unnecessary restrictive. Why can't one build rc-string from
>> stack buffers or Array!char from rc-strings? Type of output buffer
>> does not have to do anything with input.
>
> Agree. Phobos algorithms that populate a data sink should migrate toward
> using output ranges instead of returning a predetermined type. This will
> not only address ARC needs, but a bunch of other things as well (output
> range support/use in Phobos is still rather scanty at the moment).

I will mention again that output ranges lead to quite a bit more code on 
the caller site. They do give great control, but I'm hoping for 
something more convenient.

Andrei