Re: [boost] Advice on using iterator_adaptor

From: Thomas Witt (witt_at_[hidden])
Date: 2003-09-28 12:39:26

Hi Keith,

Just a short remark, more to follow.

Keith MacDonald wrote:
> 
>     class const_iterator
>         : public boost_const_iterator

This does not work, it never did and it never will. First rule of 
iterators: Don't derive from an iterator.

The reason is that the operator return types get messed up. BTW this is 
the reason why ia uses the CRT pattern.

const_iterator x;
const_iterator y = ++x; // Uuups does not compile

++x returns a boost_const_iterator!

Thomas