Geometry Boost List: [ggl] changes for consistency

Subject: [ggl] changes for consistency
From: Barend Gehrels (Barend.Gehrels)
Date: 2009-10-21 10:03:48

Hi,

1) The access traits class has been modified to avoid indirection and to 
be consistent with indexed_access. The change is that the Dimension 
template parameter is now the second template parameter of the struct, 
instead of a member template parameter of the set/get functions.

All point structures, registration macro's, tests and examples are 
updated with this respect. Probably your code does not need to change.

However, if you specialized your traits class yourself, you have to change:

from: template <> struct access<mypoint> { template <int Dimension> 
static double get(...) {...} /and also set/ };

to: template<std::size_t Dimension> struct access<mypoint, Dimension> { 
static double get(...) {...} /and also set/ };

The old construct was rather old and could be a bit unhandy in case of 
specializing for e.g. .x and .y. This needed earlier either an 
'accessor', second specialized struct, or it could be implemented using 
an if(Dimension == 0) etc, which is an inferior solution. The new 
construct can be specialized per dimension, or for one dimension 
forwarding to e.g. boost.tuples.

If there are any questions I'll be helpful.

2) For consistency, I propose also to modify the strategies to have an 
"apply" method by default, instead of operator(). The operator() was to 
enable functors (C functions) but they cannot be used anyway, in 
(nearly) all cases, because there are type definitions expected by the 
enclosing code. It was decided to have "apply" everywhere, so also here. 
The simplify-strategy did not have an operator() but a method "simplify" 
which is now also renamed to "apply" (besides some other enhancements)

3) Related to this I also added "concept checking" files for the 
strategies (distance & simplify now).

4) simplify with an output iterator is now renamed to simplify_inserter 
(like convex_hull_inserter, and like std::back_inserter). This also 
solves the fact that it didn't work for linestring-to-linestring, that 
is working now again.

Besides all these I'm slowly adding tests and updating documentation. 
Test and example folders have a Jamfile now (as expected) and can be 
tested using bjam

Regards, Barend
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