Re: map vs. set (stl)

From:
Markus Schoder <a3vr6dsg-usenet@yahoo.de>
Newsgroups:
comp.lang.c++
Date:
23 May 2007 20:59:44 GMT
Message-ID:
<pan.2007.05.23.20.59.16@yahoo.de>
On Wed, 23 May 2007 12:41:18 -0700, Qwavel wrote:

Let's say I have something like this, where 'name' is a POD type, and
'value' is a class.

std::map< name, value >

But then I realize that 'name' should actually be one of the members of
'value' class, so I have a redundancy. I then switch and start using
std::set< value >. To make 'value' suitable for this purpose, I make it
look like this...

class value {
  const int name;
  bool operator<( const value& rhs ) const
     { return name < rhs.name; }
  void operator=( const value& rhs );
  ...
};

This now satisfies the requirements of a set, and it works. Great. But
I feel as though I have really strayed far from the idea of a set. For
example, the key part of my value is constant, but the whole value is
not.

Should I really be using a set like this?


The problem you might be facing is that you cannot (without casting)
modify the objects in the set through a set iterator. A set iterator is
basically always a const iterator to prevent breaking the ordering of the
set.

--
Markus Schoder

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