[boost] Re: [preprocessor] vertical and horisontal repititions

From: Gennadiy Rozental (gennadiy.rozental_at_[hidden])
Date: 2002-11-07 22:05:24

> > Could somebody explain the difference and when which one should be used.
> >
> > Also is there PP desing paper that explain how it is
working/implemented?
>
> Vertical repetition is primarily for large scale repetition--such as
> repetition or whole functions or class definitions.  Horizontal repetition
> is better (IMO) for small things like "class T0, class T1, class T2"
(etc.).

You don't really answer the quesion. Why should I bother how postprocessed
code look like? Vertical or horizontal - in majority of the cases I don't
look on the code produced and for compiler it should be indifferent.

Gennadiy.

P.S. One more remark: it seems like notion of state is used differently in
different places of the documentation. In one place (BOOST_PP_WHILE or FOR)
state means what I expect it to mean state of the loop, while in others it
used as "State Parameters" used to provide the means to reenter the
respective construct

P.P.S. From what I view constructs that are used for looping are not
substitutable, like one would expect from C++ expirience. Instead each has
specific pattern of usage and area of application. BTW it would be great to
specifically show in which case which construct should be used in docs.