From: David Abrahams (dave_at_[hidden])
Date: 2005-02-24 12:28:47
"Arkadiy Vertleyb" <vertleyb_at_[hidden]> writes:
> "David Abrahams" <dave_at_[hidden]> wrote in message
>> "Arkadiy Vertleyb" <vertleyb_at_[hidden]> writes:
>> > Hi all,
>> > I am having a huge compile performance problem trying to use mpl::begin
>> > an mpl::vector of a large size -- the complexity seems to be far from
>> > constant (or even linear) time. The following example demonstrates it
> (I am
>> > using GCC 3.3.3 or 3.4.2)
>> Are you sure you're not seeing preprocessor slowness?
> I modified the example to get the PP code out:
> typedef BOOST_PP_CAT(boost::mpl::vector, BOOST_TYPEOF_LIMIT_SIZE)<
> BOOST_PP_ENUM(BOOST_TYPEOF_LIMIT_SIZE, MACRO, ~)
> #warning started getting begin
> typedef boost::mpl::begin<v>::type it;
> #warning done getting begin
> It takes about 35 seconds between two warnings....
> The similar problem seems to exist for at<>. It takes forever to compile
> at<v, int_<0> > in the same context.
Well, we need to hear from Aleksey on this one, I guess.
-- Dave Abrahams Boost Consulting www.boost-consulting.com
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