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From: Eric Niebler (eric_at_[hidden])
Date: 2007-04-17 19:48:48

Maurizio Vitale wrote:
> Good day,
> The following example conceptually builds on the previous one I've
> posted (but it is self contained). It requires boost::proto from CVS
> head, as Eric has fixed one or two bugs. Thanks, Eric!

No problem!

> What it does is to define two user defined types, my_int wrapping
> ints, and my_uint wrapping unsigned ints.
> It then defines two grammars, my_grammar which allows arbitrary mix of
> signed and unsigned quantities and my_segregated_grammar which doesn't
> allow those incestuous relations.
> Furthemore, the example does allow to modify the normal C++ rule for
> when signed and unsigned are mixed together: define priority to be
> magnitude_c and you get the standard (and not particularly useful,
> imho, C/C++ rule). Define priority to be two_complement_c and you get
> the rule I really need for SystemC: if signed is combined with
> unsigned, signed win.

Pretty cool.

> The code is public domain. If anybody see something bad in the code,
> let me know. I've noticed myself the lack of comments, no need to
> mention it :-)

Looks good to me.

Eric Niebler
Boost Consulting

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