• Pablo Aguilar (35/35) Apr 18 2007 Hi,

Pablo Aguilar <pablo.aguilar gmail.com> writes:

Hi,

While enjoying my short-lived vacations (4 days =S), I found myself 
programming with COM *shudder*.

I hadn't used ref_ptr + interface_cast, and now that I have, I have to 
say I really like the way my new code looks.

But, as you're probably expecting, there's a couple of issues I ran 
into, namely:

1) There's interface_cast_addref and there's interface_cast_noaddref. I 
*think* I understand what to expect from each. But then there's 
interface_cast with no suffix, and now I'm wondering, what does it do? 
Maybe it's just the programming-at-3am thing that's getting to me, 
but... I found it hard to guess =( I'll admit to not having read the 
help file yet, but still I think there's to fix here.

2) For some reason I can't figure out, IInputObjectSite doesn't have an 
associated REFIID that __uuidof can retrieve. Thus IID_traits complains 
when trying to do so. I tried specializing the template, but that didn't 
seem to work (using Visual Studio 2005, btw), the compiler error remains 
the same. But even if that had worked, I figured, why not have an 
optional parameter to give interface_cast the REFIID it needs, at the 
call site. I agree it's better to have a single place where that's 
defined and be done with it (i.e. specialize the template, and expect it 
to work) but the, I'm only using that one interface at one place, so why 
not have it 'just work'?

The one other drawback of the template specialization, is that I have to 
know the namespace where to put it in.  At first I tried comstl, but 
that's just an alias, so I couldn't do that, then I went on to check the 
header file, which reminded me of the stlsoft::comstl_project namespace 
hierarchy, and all that surrounded by conditional compilation 
directives! It's all good if you're the library writer, but I don't want 
to have to figure out and repeat the way the library works. After all, I 
just want a single failing cast to work! =P

Hope I made my motivation clear...

Thanks!,
Pablo


P.S. I'd bet you missed my essay-sized posts! ;)