{

my_point(double an_x = 0, double an_y = 0)

: x(an_x)

, y(an_y)

{}

double x, y;

{

// required for a polygon: an outer ring...

my_ring boundary;

// ... and a Boost.Range compatible inner ring collection

std::array<my_ring, 2> holes;

// just for the sample

std::string name;

my_polygon(std::string const& n = "") : name(n) {}

{

my_polygon p1("my polygon");

// Fill it the my-way, triangle

p1.boundary.push_back(my_point(2, 0));

p1.boundary.push_back(my_point(1, 5));

p1.boundary.push_back(my_point(7, 6));

p1.boundary.push_back(my_point(2, 0));

// Triangle

p1.holes[0].push_back(my_point(2, 1));

p1.holes[0].push_back(my_point(2.4, 2));

p1.holes[0].push_back(my_point(1.9, 2));

p1.holes[0].push_back(my_point(2, 1));

// Box

p1.holes[1].push_back(my_point(3, 3));

p1.holes[1].push_back(my_point(4, 3));

p1.holes[1].push_back(my_point(4, 4));

p1.holes[1].push_back(my_point(3, 4));

p1.holes[1].push_back(my_point(3, 3));

std::cout << "Representation of " << p1.name << ": "

<< boost::geometry::dsv(p1) << std::endl;

std::cout << "Area of " << p1.name << ": "

<< boost::geometry::area(p1) << std::endl;

std::cout << "Perimeter of " << p1.name << ": "

<< boost::geometry::perimeter(p1) << std::endl;

std::cout << "Centroid of " << p1.name << ": "

<< boost::geometry::dsv(boost::geometry::return_centroid<my_point>(p1)) << std::endl;

return 0;