Re: [boost] [TTI] Review

Subject: Re: [boost] [TTI] Review
From: Jeffrey Lee Hellrung, Jr. (jeffrey.hellrung_at_[hidden])
Date: 2011-07-12 16:57:15

On Tue, Jul 12, 2011 at 10:23 AM, Edward Diener <eldiener_at_[hidden]>wrote:

> On 7/11/2011 11:55 PM, Jeffrey Lee Hellrung, Jr. wrote:
>
>> [I have not looked in detail at the TTI library and only *just* caught up
>> on
>> this email exchange...whew!]
>>
>> On Mon, Jul 11, 2011 at 8:07 PM, Lorenzo Caminiti<lorcaminiti_at_[hidden]**
>> >wrote:
>>
>>  On Mon, Jul 11, 2011 at 10:53 PM, Edward Diener<eldiener_at_[hidden]*
>>> *>
>>> wrote:
>>>
>>>  [...]
>>
>>  I do not like your syntax. I much prefer the syntax I already have, with
>>>>
>>> a
>>>
>>>> separate macro parameter merely being the template parameters if the
>>>> end-user is looking for a match, ie.
>>>>
>>>> TTI_TEMPLATE(mytpl,BOOST_PP_**NIL)
>>>> TTI_TEMPLATE(mytpl,(class)(**int)(template<typename class>  struct))
>>>>
>>>
>>>
>> This is acceptable.
>>
>>
>>  or for variadic macros
>>>>
>>>> TTI_TEMPLATE(mytpl)
>>>> TTI_TEMPLATE(mytpl,class,int,**template<typename class>  struct)
>>>>
>>>
>>>
>> Didn't Paul Mensonides (sp? sorry Paul!) rail against such constructs just
>> a
>> week or two ago? :)  I.e., shouldn't the template signature be packaged
>> into
>> a single parameter?
>>
>
> I do not know what you are referring to regarding Paul Mensonides' opinion
> but a large part of variadic macros value, IMO, is that they provide a
> better syntax for the end-user while the pp-lib data types provide much
> richer functionality internally. So I see no reason why the variadic macro
> syntax should not be provided for end-user use.
>

Perhaps I'm misinterpreting and/or reading too much into

http://article.gmane.org/gmane.comp.lib.boost.devel/221076

e.g.,

"> BOOST_LOCAL_PARAMS(int x, int& y) // (1) BOOST_LOCAL_PARAMS( (int x)
[...]
Regardless, I actually believe that the (1) case above is actually a
large step *backwards*.  It's worse, not better, because it's trying (and
failing) to be the underlying language and introducing a bunch of gotchas
in the attempt."

and subsequent follow-ups, e.g.,

http://article.gmane.org/gmane.comp.lib.boost.devel/221104

and, if so, let me know, but I read this and think (among other things),
wouldn't it be better to package the template signature up into a single
parameter?  For one thing, this would simplify the use of TTI_TEMPLATE
within preprocessor structures, wouldn't it?  I'm not saying we can't take
advantage of variadic macros, I'm just saying maybe we shouldn't make
TTI_TEMPLATE a variadic macro (okay, other than accepting 1 argument,
"mytpl", or 2 arguments, "mytpl" and the template signature).

- Jeff