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Subject: Re: [boost] [GSoC][MPL11] Post C++Now update
From: Larry Evans (cppljevans_at_[hidden])
Date: 2014-05-20 16:20:31

On 05/20/14 13:59, Larry Evans wrote:
> On 05/18/14 15:41, Louis Dionne wrote:
>> Request for guinea pigs
>> -----------------------
>> I am looking for people with hardcore C++1y metaprogramming needs who
>> will
>> be willing to test the library I come up with (MPL11 or MPL + Fusion
>> merge).
>> I also need to see use cases for the library, so please reply even if you
>> are not willing to test.
> As mentioned in this post:
> One use case is:
> > 3) A guaranteed non-recursive way to access elements of parameter
> > packs
> and Doug Gregor (quoting from above post) says:
> This is probably the most-requested feature for variadic templates,
> and it never it made it because we never found a good, unambiguous
> syntax.
> The attached seems to do that. What about adding something
> like this to the library?
> -regards,
> Larry
I should clarify something from my previous post.

The at_c.cpp attachment to my previous post *did* use recursion;
however, it was template function recursion, not
template metafunction recursion.

According to:

template function recursion *should* compile faster than template
metafunction recursion. Although the above web page uses constexpr,
there's no need for that in the at_c.cpp attachment because only
the types are used, not the values (hence, the functions don't need
to be defined).

Sorry for being unclear.


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