Next in Review Queue: The New std.path

[Steven Schveighoffer]

On Mon, 18 Jul 2011 09:16:35 -0400, Lars T. Kyllingstad  
<public at kyllingen.nospamnet> wrote:

> On Sun, 17 Jul 2011 12:30:39 +0200, torhu wrote:
>
>> On 15.07.2011 02:20, dsimcha wrote:
>>> Lars Kyllingstad's new and improved std.path module for Phobos is the
>>> next item up in the review queue.  I've volunteered to be the review
>>> manager.  Barring any objections, the review starts now and ends at the
>>> ends two weeks from now on July 28.  This will be followed by a week of
>>> voting, ending August 4th.
>>>
>>> Code:
>>> https://github.com/kyllingstad/phobos/blob/std-path/std/path.d
>>>
>>> Docs:
>>> http://www.kyllingen.net/code/new-std-path/phobos-prerelease/
> std_path.html
>>>
>>>
>> Looks nice and clean, both docs and code!  I like modules that are not
>> overengineered :)
>
> Thanks!
>
>
>> I noticed a couple of things that I don't think have been mentioned
>> already:
>>
>> The docs for defaultExtension say that there's one case where doesn't
>> allocate.  But the code says that it always does (.idup isn't
>> conditional, it's just .dup with a different return type).
>
> There is no reason for idup to duplicate an array which is already
> immutable.  If it does, I'd say it is a compiler bug.

No, it has to duplicate.  Part of idup is saying "I want an immutable  
return" and the other part is saying "I want a duplicate"

For example:

string x = "hello".idup;
string y = x;

assert(x.capacity > 0); // would fail if idup just returned the same thing
x ~= " world";

assert(y is x); // would fail.

The compiler cannot know whether you care or not.

If you don't care, why are you calling idup on an immutable array?  Just  
use it.

-Steve