Geometry Boost List: [ggl] convex_hull and Geometry Concept

Subject: [ggl] convex_hull and Geometry Concept
From: Michael Caisse (boost)
Date: 2011-08-20 08:54:45

The documentation 
<http://www.boost.org/doc/libs/1_47_0/libs/geometry/doc/html/geometry/reference/algorithms/convex_hull.html> 
for the convex_hull algorithm identifies that the geometry must fulfill 
"a Geometry Concept".

It appears that convex_hull doesn't like Box Concept (which I assume is 
a Geometry Concept). Granted, the convex_hull of a box type isn't very 
interesting; however, generic programming requires a lot of 
uninteresting things  (o;

I might be missing something with the term "Geometry Concept". The 
follow little program demonstrates the problem.

Thanks -
michael

btw - results with 1.47 or trunk. With clang it actually fails the 
ConvexHullStrategy concept check. gcc just fails at the time of the 
dispatch::convex_hull.

#include <boost/geometry.hpp>
#include <boost/geometry/geometries/point_xy.hpp>
#include <boost/geometry/geometries/box.hpp>

namespace bg = boost::geometry;

int main()
{
    typedef bg::model::point<int,2,bg::cs::cartesian> point_type;
    bg::model::box<point_type> box( point_type(1,1), point_type(2,2) );
    bg::model::box<point_type> hull;

    bg::convex_hull( box, hull );

    return 1;
}

-- 
Michael Caisse
Object Modeling Designs
www.objectmodelingdesigns.com