...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
Applies function f to each point.
Applies a function f (functor, having operator() defined) to each point making up the geometry
template<typename Geometry, typename Functor> Functor for_each_point(Geometry const & geometry, Functor f)
Type |
Concept |
Name |
Description |
---|---|---|---|
Geometry const & |
Any type fulfilling a Geometry Concept |
geometry |
A model of the specified concept |
Functor |
Function or class with operator() |
f |
Unary function, taking a const point as argument |
Either
#include <boost/geometry/geometry.hpp>
Or
#include <boost/geometry/algorithms/for_each.hpp>
The function for_each_point is not defined by OGC.
The function for_each_point conforms to the std::for_each function of the C++ std-library.
Sample using for_each_point, using a function to list coordinates
#include <iostream> #include <boost/geometry.hpp> #include <boost/geometry/geometries/point_xy.hpp> #include <boost/geometry/geometries/polygon.hpp> #include <boost/geometry/io/wkt/wkt.hpp> template <typename Point> void list_coordinates(Point const& p) { using boost::geometry::get; std::cout << "x = " << get<0>(p) << " y = " << get<1>(p) << std::endl; } int main() { typedef boost::geometry::model::d2::point_xy<double> point; boost::geometry::model::polygon<point> poly; boost::geometry::read_wkt("POLYGON((0 0,0 4,4 0,0 0))", poly); boost::geometry::for_each_point(poly, list_coordinates<point>); return 0; }
Output:
x = 0 y = 0 x = 0 y = 4 x = 4 y = 0 x = 0 y = 0