C++ / Why Iterators Got It All Wrong

[Steven Schveighoffer via Digitalmars-d]

On 8/29/17 8:50 AM, Robert M. Münch wrote:
> Maybe of interest: https://www.think-cell.com/en/career/talks/iterators/#1
> 
> 
> I haven't read everything, so not sure if it worth to take a look.
> 
> 

Interesting. It reminds me a bit of cursors for dcollections. In there, 
a cursor is a 0 or 1 element range. The one element range points at an 
element, the 0 element range points at a border. You can use cursors to 
compose ranges.

https://github.com/schveiguy/dcollections

Not sure how useful it is to have them be separate types. It can be nice 
I suppose. But one thing I love about iterators/cursors is that 
something like find doesn't assume what data you are interested in.

In Phobos, find gives you a range where the first element is the one you 
searched for, and the last element is the end of the original range. But 
what if you wanted all the data *up to* the element instead? What if you 
just wanted to look at that specific element? So we need several 
functions that do this, and it's not always clear how to do it 
correctly, and it's difficult to compose one function from the other. 
With iterators, it's simple.

-Steve