Re: [boost] [Boost-interest] C++ library for runtime-concepts (type-erasure)

Subject: Re: [boost] [Boost-interest] C++ library for runtime-concepts (type-erasure)
From: Matus Chochlik (chochlik_at_[hidden])
Date: 2011-02-17 04:41:13

On Tue, Feb 15, 2011 at 10:58 AM, Germán Diago <germandiago_at_[hidden]> wrote:
[snip]

> Ok. The correct way is to reuse libraries as much as possible so that bugs can
> be corrected always in the same place. But at the same time I would
> like a syntax
> that avoids macros as much as possible. For example, my std::tuple
> inside MyClass
> uses a macro, but a very obvious one. The rest is understandable. There
> are many ways to write complicated macros, so I try to avoid them except when
> there is no other practical way.

I've added two new templates to Mirror that replace the type reflection macros:
So now instead of using MIRRORED_TYPE(X), MIRRORED_CLASS(X), ...
you can use either the mirror::reflected_type<X> or the
mirror::reflected<X> template.
Thell be available in the next release or you can get the current
version via GIT.

mirror::reflected_type<X> *is a* type conforming to the MetaType concept
and mirror::reflected<X>::type *returns a* type conforming to the
MetaType concept.

More precisely these templates provide you with types conforming
to either MetaType, MetaClass or MetaEnum, depending on how
the type X was registered with Mirror.

You can use the categorize_meta_object() function or the meta_object_category<>
template to get a tag type for tag dispatching between there concepts.

See the following three examples for comparison:
http://kifri.fri.uniza.sk/~chochlik/mirror-lib/html/mirror_2example_2typenames__01.cpp-example.html
http://kifri.fri.uniza.sk/~chochlik/mirror-lib/html/mirror_2example_2typenames__04.cpp-example.html
http://kifri.fri.uniza.sk/~chochlik/mirror-lib/html/mirror_2example_2typenames__05.cpp-example.html

I'll add a few more or update the existing examples in the near future.

This way you can avoid using macros when reflecting types. I still believe
that using macros for the registering is the right thing to do, even with all
the problems of preprocessor macros.

[snip/]

Matus