Dmitry Olshansky wrote:
On 22.07.2010 2:27, Andrei Alexandrescu wrote:
On 07/21/2010 03:35 PM, Dmitry Olshansky wrote:
Thanks for kind feedback (and showing some optimization tricks). Also
this implementation still has issues with it: it calls dtor twice. Not a
good trait for RAII technique ! :)
Since it's now considered useful I feel myself obliged to enhance and
correct it. Sadly enough I still haven't managed to apply an inner
template trick.
Here's the end result along with a simple unittest:
[snip]
The double destructor hits a bug in the compiler implementation.
Anyway, here's the committed code:
http://www.dsource.org/projects/phobos/changeset/1774
It uses a new idiom that is enabled by auto returns - defines a struct
inside the function and returns it. That's a veritable existential
type!
(http://stackoverflow.com/questions/292274/what-is-an-existential-type)
I expect more of that idiom in the upcoming commits.
A cool idiom indeed!
I guess I should clarify the double destruction problem: it was caused
by static opCall, the current implementation in Phobos does not suffers
from it.
It doesn't, but just because it uses some heavy-handed tricks such as
casting from an untyped buffer to Scoped. I found two distinct bugs by
working on Scoped, which I'll submit soon.
Andrei
