Re: [boost] 4 more associative containers.

From: Brian McNamara (lorgon_at_[hidden])
Date: 2004-02-03 08:41:35

On Mon, Feb 02, 2004 at 11:50:45PM -0800, Rich Sposato wrote:
> The containers are called flex_set, flex_map, flex_multiset, and 
> flex_multimap. They are similar to the 4 STL associative containers. 
> There are two important differences between the STL containers and these:
> 1. You can search on any type that is comparable to the key_type, rather 
> than just the key_type. (The STL associative containers only allows 
> searches on the same type as the key.)
> 2. You do *not* need to create a temporary object of key_type to search 
> through the containers. (The STL containers require you to create one 
> temporary object to search for another.)

A good idea.  I recall wishing for something like this a while ago; I
don't remember if it stemmed from an actual problem in practice or just
general unhappiness with the std:: interface in theory.

(It might be even more swell if comparators could know about
'equivalence' as well, so you could test for equivalence using one
user-defined function, rather than two calls like !c(x,y)&&!c(y,x).)

Do you have have documentation of the new 'concepts'?  Specifically it
seems like flex_xxxx<T> uses a new ComparableTo<T,U> concept to place
requirements on both the Comparator and the template arguments to
methods like find().

-- 
-Brian McNamara (lorgon_at_[hidden])