Subject: Re: [boost] [metaparse] performance comparisons?
From: Evgeny Panasyuk (evgeny.panasyuk_at_[hidden])
Date: 2015-06-07 15:49:45
07.06.2015 21:40, Roland Bock:
>
> Cool, I'll use that. It will allow users to define/use aliases in-place.
>
> But: Lamda expressions cannot live in unevaluated code. Thus
>
> using X = decltype(MAKE_CHAR_SEQUENCE(delta));
>
> is illegal :-(
Yes, this limitation was discussed a bit earlier -
http://boost.2283326.n4.nabble.com/Boost-announce-metaparse-Review-period-starts-May-25th-and-ends-June-7th-tp4675772p4676677.html
(and below)
I think that we should have several versions of CT string macros in
Boost - because unfortunately there are different trade-offs for
different approaches.
>
>>
>>> Thus, while I assume that it is faster than what happens inside the
>>> MPLLIBS_STRING (haven't measured it), its use is more limited, too.
>>
>> As I understand, complexity of MPLLIBS_STRING comes from fact that it
>> can be passed immediately as template argument.
>>
> I guess so, too.
>
> MAKE_CHAR_SEQUENCE can be used as a function argument at least :-)
>
I used it following proof-of-concept - https://github.com/panaseleus/ctte
And it was perfectly optimized by compiler (identical ASM code with
handwritten version)
Best Regards,
Evgeny Panasyuk