emplace, scope, enforce [Was: Re: Manual...]

[Andrei Alexandrescu]

Philippe Sigaud wrote:
> On Thu, Jul 22, 2010 at 00:27, Andrei Alexandrescu 
> <SeeWebsiteForEmail at erdani.org <mailto:SeeWebsiteForEmail at erdani.org>> 
> wrote:
> 
>     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..
> 
> 
> Hmm, so the struct Scoped is implicitly parametrized by T and Args.... Cool.
> 
> Why do you put a second layer of (Args...) in Scoped constructor? Why 
> not just
> 
> this(Args args) if (etc) {...}
> 
> And, in your case, if you used Args inside Scoped (which you don't do), 
> would that be the ctor's Args which'd be used?
> 
> 
> Philippe

Great point. I simplified the implementation:

http://www.dsource.org/projects/phobos/changeset/1776

> PS: too bad that, if bug 2581 is not squashed, your scoped won't show in 
> the docs :(

I'll fix that later with a version(ddoc).


Andrei