From: Markus Werle (numerical.simulation_at_[hidden])
Date: 2003-05-07 06:57:29
Terje Slettebø wrote:
>>From: "Markus Werle" <numerical.simulation_at_[hidden]>
>> At http://daixtrose.sourceforge.net/ You can find an
>> implementation of this idea, code that may serve as a base
>> for boost::etl, if there is any interest.
> Have you looked at PETE (Portable Expression Template Engine)
> (http://www.acl.lanl.gov/pete/), and how it compares? Perhaps you could
> have provided a comparison.
I will try a short summary. Also consider the
Daixtrose quicktour at
With regard to the core Expression Template engine one
can say that both libs use a similar approach.
IMHO Daixtrose takes these ideas a little bit further:
Daixtrose additionally offers
- a fine-grained disambiguation mechanism which gives You
a compiler firewall against accidentical wrong combinations
of incomaptible types, while offering a convenient way to
express that e.g. a matrix times vector yields a vector result.
- User's choice between reference- _or_ copy-semantics
based on traits _or_ special member typedefs.
- compile-time analytic differentiation
- compile-time expression simplification:
(a - a) yields 0 at _compile_ time.
- On-the-fly attacheable run-time polymorphism:
adding features (say member functions)
to an arbitrary expression such that
Matrix M1, M2;
(M1 + M2).operator()(1, 2);
can be implemented without paying for it in places where You do
not need it. Also storing pointers to arbitrary expressions
is easy through this feature.
- feature groups sectioned in namespaces, so using another
ET lib in the same place should be possible without pain.
- extensible/adaptable pretty-print features
Daixtrose misses direct STL-like support
(now in boost::mpl::foreach etc.)
or features like
assign(d, a + b * c);
a += where(d < 30, b, c);
but these can of course be built using daixtrose.
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