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Subject: [boost] New Container: Hashed Vector
From: Sam Hertz (slhertz_at_[hidden])
Date: 2011-12-03 21:29:56

Boost Developers,

Let me start by saying that I love the Boost Libraries. I use them
Most of the time, when I need some unique data structure in my code, Boost
can solve my problems.
I saw the recent release of the Container library and I love the idea of
the flat_set/map structures.

In my code, I require a data structure that has fast associative lookup
(like an unordered_set). However, this data structure should preserve the
order of element insertion. In other words, the data structure would be
similar to the flat_set/map structures, but would preserve order of
insertion instead of relying on the < operator or a Comparable function
object. Right now, I am calling this structure a hashed_vector.

I am aware of Boost.Multi-Index, but this library is very general purpose
and cumbersome to use to implement a hashed_vector. Ideally the structure
would have an identical interface to the std::vector class, but with a much
speedier find member function. Right now I am creating a wrapper class for
multi_index_container to implement the hashed_vector, but hopefully a more
direct implementation could be added to the Boost Libraries.

I am sharing this idea with all of you because I want to see if you think
such a structure is worth including in the libraries and if anyone is
interested in implementing it. I would love to implement it myself, but I
am currently a full-time graduate student and my experience with template
programming is laughable when considering the amount currently used in the
Boost Libraries.

Looking forward to your feedback!


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