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

The documentation
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 -

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

#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	

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