Re: std::set as search tree - manipulate elements?

From:
Alberto Ganesh Barbati <AlbertoBarbati@libero.it>
Newsgroups:
comp.lang.c++.moderated
Date:
Thu, 17 Jul 2008 12:28:10 CST
Message-ID:
<sXJfk.118293$FR.378746@twister1.libero.it>
Rune Allnor ha scritto:

The problem is the tagged line. Apparently, all elements
in std::set are declared 'const', so I am not allowed to
manipulate the elements directly. Do note that I do *not*
manipulate the histbin::bin element, which is used as the
key for sorting, and thus it ought to be safe to manipulate
the histbin::count elements.


It's difficult for library to understand that "it ought to be safe" to
modify the element. std::set takes the safe side and make the all object
const. If you want to modify a part of the object unrelated to the key,
you can declare the non-key part mutable, use a const_cast or...

Is there a convemient, safe way to be able to use std::set
as the search tree for this histogram?

If 'no', are there other STL containesr that can be used?
I would prefer not to have to implement a tree from scratch,
but if there are no alternatives I would like to know that
early on, and just get to work...


..... just use std::map. In your case, I would go for the latter.

Ganesh

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