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?