How does memoized work? Does it make a copy of the element? Does it use dynamic allocation? Thanks, Nate. ----------------------------------------
Date: Wed, 1 Jun 2011 12:39:51 +0900 From: faithandbrave@gmail.com To: boost-users@lists.boost.org Subject: Re: [Boost-users] [range] filtered dereferences underlying range elements twice
High cost sometime if filtered always store dereferenced-value. I think memoized adaptor was better to external store design. or add stored_filtered adaptor.
2011/6/1 Akira Takahashi :
Nate, follow is filtered + transformed adaptor's internal behavior.
[filtered] increment iterator behavior: while (!pred(*it)) ++it;
dereference iterator behavior: *it;
[transformed] increment iterator behavior: ++it;
dereference iterator behavior: f(*it);
[filtered | transformed] increment iterator behavior: while (!pred(*it)) ++it;
dereference iterator behavior: f(*it);
[transformed | filtered] increment iterator behavior: while (!pred(f(*it))) ++it;
dereference iterator behavior: f(*it);
oven::memoized is call once function by stored calculation.
2011/6/1 Nathan Ridge :
Thanks Akira, it is good to know that there is a workaround.
But I was wondering, is it necessary in the first place for filtered to dereference the underlying range elements twice?
Thanks, Nate.
======================== Akira Takahashi mailto:faithandbrave@gmail.com blog:http://d.hatena.ne.jp/faith_and_brave/
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