Re: Differences between multimap and map of vector

From:
"Daniel T." <postmaster@verizon.net>
Newsgroups:
comp.lang.c++.moderated
Date:
18 May 2006 17:24:15 -0400
Message-ID:
<postmaster-9A9CE4.21122017052006@news.west.earthlink.net>
In article <1147861547.094797.208550@u72g2000cwu.googlegroups.com>,
  "Gianluca Silvestri" <silvestri.gianluca@gmail.com> wrote:

Hi all,

I have to maintain a map with string as a key and several objects
referring to the same key held by pointer.

I am uncertain whether to lay out the structure as a multimap<string,
CMyData*> or as map<string, vector<CMyData*> >. My concerns are about
speed and space, obviously.

It is very likely that,given a key, most of the times I will refer to
all of the objects and rarely I will have to search for a specific
object.


I'd say, if your not sure, then wrap it in a class of your own devising.
See how your interface grows and changes with your programs need and
make sure that it's designed in such a way that you can swap out one
implementation for the other with no rework on the client side. Then you
can profile your code and see which is really better for you, and switch
to it with little effort.

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