[boost] Re: Re: [iterator facade] Why is dereference const?

From: Neal D. Becker (ndbecker2_at_[hidden])
Date: 2004-05-17 12:15:30

John Torjo wrote:

> Neal D. Becker wrote:
> 
>>Thanks for the advice.  I think I have it now.
>>
>>Problem:
>>
>>  A function F accepts a pair of stl-style iterators as input.  A nullary
>>functor G can generate an output.  Arrange for F to call G n times without
>>storing to an intermediate sequence.
>>
>>Example: G is a random number generator.
>>
>>I wonder if there is a more elegant approach?  Here is what I came up
>>with.
>>  
>>
> Yes, there is.
> rtl (Range Templates Library) has a generate_iterator.
> 
> You have a generator, and a stopper. From these, you create an input
> iterator sequence. The stopper tells you when you've reached end.
> 
> For instance:
> // input iterator sequence - 20 fibonacci numbers
> generated(fibonacci(), gen_n(20))
> 
> // input iterator sequence - fibonacci numbers up to 200
> generated(fibonacci(), gen_upto(200))
> 
> You can use it like this:
> rng::copy( generated(fibonacci(), gen_upto(200)),
> std::ostream_iterator<int>(std::cout," "));
> 
> The rtl (and the generate* examples) can be found at:
> www.torjo.com/code/for_boost.zip
> 
> 

The RTL approach looks very interesting.  There is a lot to digest here.  

What is the state of maturity of this code?  Would you consider it ready for
use?