At Sat, 26 Feb 2011 19:07:37 +0100, Domagoj Saric wrote:
"Dave Abrahams" <dave@boostpro.com> wrote in message news:m262s6r9pi.wl%dave@boostpro.com...
I think you don't understand how MPL maps work and you missed the mechanism in Boost.Parameter. Therefore, I think you don't understand the source of the slowdown.
It might well be so...but...the slowdown almost disappeared when I replaced argument packs with mpl::maps...and the only thing that I know of that went with along with that change is the type requirements checking...so it's either arg-pack lookup or the requirement checking...
Likely the latter, but it could still be something else. Template compilation speed is still something of a black art.
We gave that approach serious consideration and would of course have preferred to do it that way. I don't recall the reasons we decided against it.
That's what comments are for :P
Thanks, dad.
Perhaps it was exactly compile time performance (i.e. you wanted more descriptive names, e.g. template_keyword instead of mpl::pair, and that would require wrapping mpl types which incurs additional instantiations...)...
Probably.
Well, the first step I guess would be to disable type requirement validation and measure the difference...
ps. have you used SW's template profiler (with B.P.) ?
Not yet.
Well if you are really into trying to improve Boost.Parameter the two obvious things to try is the elimination of the requirement checks and SW's template profiler...I am willing to help however I will not be by my work computer for the next 10 days...
I won't have time to get near that code in the next 10 days, so I can wait :-) -- Dave Abrahams BoostPro Computing http://www.boostpro.com