Re: [boost] Re: rtl (Range Template Library)

From: John Torjo (john.lists_at_[hidden])
Date: 2003-11-20 19:13:27

Hi Larry,

> 
>> The idea I am pushing for here is that ranges ARE NOT pairs of 
>> iterators.  Rather, a pair of iterators happens to make a good 
>> representation of a range, but may not be the only one.
>>
>> Taking the example of a forward range.  All we really need is a 
>> starting point (not sure there is a substitute for iterator here) and 
>> an 'end test'.
> 
> Another example is an "flattening" iterator over, for example, the
> leaves of a tree or selected nodes in a tree.  I needed this in
> http://groups.yahoo.com/group/boost/files/shared_cyclic_ptr/stl_container.cpp 
> 
> and used my own range iterator.  It was implemented using begin/end
> iterators, but the empty() method couldn't just compare two iterators.
> 

Could you explain a little further, please? I took a look at the code, but 
failed to see it. Anyway, interesting coding style;)

What does empty() do - why doesn't it just compare two iterators?

Best,
John