Hi Luke,
Fernando,
Please take a look at my post with subject "operator syntax proposal checked into sandbox" in which some of your questions are answered.
I'll answer the questions you wont' find answers to in that post below:'
The user must register their type as a polygon set type:
template <> geometry_traits<std::list<UserPolygonType> > { typedef polygon_set_concept geometry_concept; };
This is probably explained somewhere but, could you state what a
geometry_traits<T>::geometry_concept
is?
It is a struct that declares all functions that relate specifically to a geometry concept.
Sorry, I meant to as what a "geometry concept" is? at a entirely conceptual level. I ask becasue I can't infer the meaning from the name (to it feels as it where "lucanus_concept" :)), nor from the particular polygon_set_concept example.
I would like better if the library used a general expression templates framework instead of a custom mechanism so it can be used in much more than just polygon set operations. But then of course, does boost has any of that already?
I'm not sure what you mean here.
I meant that lazy evaluation is the job of expression templates and that can (and should IMO) be intrumented by an *external* general framework for that purpose, like the pioneer PETE (http://acts.nersc.gov/pete/). IOW, this shouldn't by just an ad-hoc mechanism within some portions of your library if possible.
This proposed API is the most concise and intuitive way I can think of to provide these algorithms to the library user.
Do you mean the operator syntax or the lazy evaluation? I don't care for the former, but I certainly do for the latter, and to a broader extent.
I meant the operator syntax. The lazy evaluation is currently implemented as computing the full result of an operation only when it is used,
Indeed, which with a right framework becomes a property of any computation, not just clipping.
but could be pushed further to have lazy iterator algorithms that produce the next increment of a result of an operation only when required. Whether there is advantage in doing so, however, is currently unclear.
Right, I woudn't aim that far up now. Best -- Fernando Cacciola SciSoft http://scisoft-consulting.com http://fcacciola.50webs.com http://groups.google.com/group/cppba