Re: [Boost-users] Using unordered_set or unordered_map to hold small array(s) of ints

Subject: Re: [Boost-users] Using unordered_set or unordered_map to hold small array(s) of ints
From: B Hart (bhartsb_at_[hidden])
Date: 2010-08-20 18:07:35

Just a comparison function?  How is, for example, unordered set going to
know the end of the array, to hash it?  I don't know what is happening
under-the-hood so I'm deferring to the list experts.

Can you give me a simple example?

On Fri, Aug 20, 2010 at 4:31 AM, OvermindDL1 <overminddl1_at_[hidden]> wrote:

> On Fri, Aug 20, 2010 at 2:21 AM, B Hart <bhartsb_at_[hidden]> wrote:
> > Can someone please provide an example of how to best use
> unordered_map/set
> > to store/lookup many small arrays of integers.  e.g. unsigned int I[5] =
> > {1000,3344455,12455222,8832232};
> > I'm guessing that there is no facility for using raw C++ arrays, and that
> > one must wrap them in a struct.
>
> I guess you mean C arrays and not C++ arrays as C++ arrays are
> probably std::vector's.
>
> C arrays or C++ vectors would work fine though, but you would need to
> supply your own comparison function, and if C arrays add an ending tag
> like zero or have a static length.
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