On Wed, Mar 26, 2008 at 11:33 AM, Steven Watanabe <watanabesj@gmail.com> wrote:

AMDG

Robert Dailey wrote:
> Would you mind going over what exactly this is doing? I'm having a
> hard time wrapping my head around it. The documentation isn't helping
> much either, as I've never used these before and the descriptions are
> very confusing.
>
> I also didn't see a version of mpl::transform that only took 1
> template argument. Is this correct?

You're right. I was in too much of a hurry before.
Here's something that actually compiles.

<snip>

In Christ,
Steven Watanabe

The term 'inherit' here does not refer to class inheritance obviously. It's an unusual usage of the term to me. When you do inherit<empty_base, WalkPacket> what exactly is that doing? Is it joining them in a list container or something? What is the resulting type of mpl::inherit_linearly::type? Is the result of mpl::inherit_linearly::type implicitly constructible from an mpl::transform::type? I'm going to read over the docs a few more times in the meantime to see if I can grasp this concept. Also, I'm not seeing how you're filling in the 2 placeholders in the signal_holder typedef.

Also, mpl::vector has a max size limit I'm sure. Right now we have a very minimal set of packet types, but in the future we have to consider the possibility that 100+ packet types will exist (the final number is ultimately unknown). If this is true, I doubt mpl::vector would be usable anymore since 100 seems too large for it. This makes me feel like I'm going to have to resort to a completely template-less approach. I might have to send a generic Packet object to all subscribers, which has a ::Get() method that performs a static_cast<>() to the concrete type based on an ID.

The only reason I haven't decided to use your ideas so far (which are extremely great by the way) is because of the limitations of the design. The design imposes a limit on the number of packet types we can support, which isn't acceptable given the requirements.

Thanks again for your help.