{

using namespace boost::geometry;

using namespace boost::assign;

{

typedef model::d2::point_xy<double> point;

typedef model::polygon<point> polygon;

typedef model::linestring<point> linestring;

// Boost.Assign automatically works for linestring, rings, multi-geometries

// It works because these are std:: containers

// Using Boost.Assign operator +=

linestring ls1;

ls1 += point(1,2);

ls1 += point(3,4), point(5,6), point(7,8);

std::cout << dsv(ls1) << std::endl;

// Using Boost.Assign operator()

linestring ls2;

push_back(ls2)(point(1, 2))(point(3, 4));

std::cout << dsv(ls2) << std::endl;

// Using Boost.Assign list_of

linestring ls3 = list_of(point(1,2))(point(3,4));

std::cout << dsv(ls3) << std::endl;

// Using Boost.Assign + Boost.Range

linestring ls4;

push_back(ls4)(point(0, 0)).range(ls2).range(ls3);

std::cout << dsv(ls4) << std::endl;

// For a ring, it is similar to a linestring.

// For a multi-point or multi-linestring, it is also similar

// For a polygon, take the exterior ring or one of the interiors

polygon p;

push_back(exterior_ring(p))

(point(0, 0))

(point(0, 2))

(point(2, 2))

(point(2, 0))

(point(0, 0))

;

std::cout << dsv(p) << std::endl;

}

{

// It is convenient to combine Boost.Assign on a geometry (e.g. polygon) with tuples.

typedef model::polygon<boost::tuple<double,double> > polygon;

polygon p;

exterior_ring(p) = tuple_list_of(0, 0)(0, 5)(5, 5)(5, 0)(0, 0);

std::cout << dsv(p) << std::endl;

// And let it work on the interior_rings as well

push_back(interior_rings(p))

(tuple_list_of(1, 1)(2, 1)(2, 2)(1, 2)(1, 1))

(tuple_list_of(3, 3)(4, 3)(4, 4)(3, 4)(3, 3))

;

std::cout << "Area of " << dsv(p) << " is " << area(p) << std::endl;

}

return 0;