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From: Paul Mensonides (pmenso57_at_[hidden])
Date: 2004-11-14 05:03:54


> -----Original Message-----
> [mailto:boost-bounces_at_[hidden]] On Behalf Of Alexander Nasonov

> Paul Mensonides wrote:
> > That might work because there is no need to ever touch (buf, len).
> > That is not guaranteed, however.
>
> Is it right that it's not guaranteed only because it doesn't
> conform to sequence interface?

Yes. Firstly, sequences contain unary elements. In the larger scheme of things
a sequence according to the pp-lib is a "unary sequence". Other sequences are
possible (such as binary sequences) without variadics, but there is no support
for them in the pp-lib. Variadic sequences, meaning sequences whose elements
are any arity, can only be supported with C99's variadic macros. Even so, there
is no support for them in the pp-lib (yet). Secondly, because of how broken
many preprocessors are, the pp-lib does quite a few major hacks (a.k.a.
workarounds) to make things work. It is doing a lot of things that aren't
necessary from a theoretical point of view, but are necessary in practicality.
Because of that, adding side guarantees or allowances is difficult. That might
not be the case here, but there is no real reason to add such a guarantee.

Regards,
Paul Mensonides


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