Re: [boost] Comment on string / unicode discussion

From: Robert Ramey (ramey_at_[hidden])
Date: 2006-07-06 15:05:29

David Abrahams wrote:
>>> Maybe you never articulated sufficiently clearly what you added to
>>> the basics provided by the iterator library, and why.
>>
>> LOL - apparently so.

Of course there is another possibility - that it's clear how it works but
no one sees the appeal of the approach.  A previous time when ranges
was being discussed, I flogged this idea and there was a strong objection
raised to the nested template syntax.  Funny thing was - that is exactly 
what
I love about this. Its the compile time counter-part of the common
way of composition invoked at run time.  When iostreams code
conversion was being discussed I also tried to promote the idea - but
I think it was seen as to "far out".   I suspect that a large part is
aesthetic and what people are familiar with.  It started out as an
experiment with the then new boost iterators.  As I progressed
I became more enthusiastic about the idea.  It was of immense
help with implementing the more tedious aspects of the serialization
library and has needed almost no maintainence.  So I'm very
happy with it.  In my view it - or something like it - provides the
answer to the question which started this thread- whatever that
was.

> Thanks; I think I see why you need the templated ctors now.
>
> w.r.t. composing with a typedef, would
>
>     boost::archive::iterators::insert_linebreaks<
>         boost::archive::iterators::base64_from_binary<
>             boost::archive::iterators::transform_width<
>                 const char *,
>                 6,
>                 8
>             >::type
>        >::type
>         ,72
>         ,const char // cwpro8 needs this
>     >::type
> base64_text;
>
> be much worse, for your purposes?

Hmmm - I read this as creating an instance of base64_text - presumably on 
the stack.

I don't see how I could use this to do:

> std::copy(
>     base64_text(address),
>     base64_text(
>         address + count
>     ),
>     oi
> );

which is what I REALLY wanted to do.

Robert Ramey