|  | Home | Libraries | People | FAQ | More | 
Assign a range of points to a linestring, ring or polygon.
template<typename Geometry, typename Range> void assign_points(Geometry & geometry, Range const & range)
| Type | Concept | Name | Description | 
|---|---|---|---|
| Geometry & | Any type fulfilling a Geometry Concept | geometry | A model of the specified concept | 
| Range const & | Any type fulfilling a Range Concept where it range_value type fulfills the Point Concept | range | A range containg points fulfilling range and point concepts | 
Either
            #include <boost/geometry.hpp>
          
Or
            #include <boost/geometry/algorithms/assign.hpp>
          
| ![[Note]](../../../../../../../../doc/src/images/note.png) | Note | 
|---|---|
| Assign automatically clears the geometry before assigning (use append if you don't want that) | 
Shows usage of Boost.Geometry's assign, Boost.Assign, and Boost.Range to assign ranges of a linestring
#include <iostream> #include <boost/geometry.hpp> #include <boost/geometry/geometries/linestring.hpp> #include <boost/geometry/geometries/adapted/boost_tuple.hpp> #include <boost/assign.hpp> #include <boost/geometry/geometries/adapted/boost_range/filtered.hpp> BOOST_GEOMETRY_REGISTER_BOOST_TUPLE_CS(cs::cartesian) template <typename T> struct x_between { x_between(T a, T b) : fa(a), fb(b) {} template <typename P> bool operator()(P const& p) const { return boost::geometry::get<0>(p) >= fa && boost::geometry::get<0>(p) <= fb; } private : T fa, fb; }; int main() { using namespace boost::assign; typedef boost::geometry::model::linestring<boost::tuple<int, int> > ls; ls line1, line2, line3; line1 = tuple_list_of(0, 0)(2, 3)(4, 0)(6, 3)(8, 0)(10, 3)(12, 0);boost::geometry::assign_points(line2, tuple_list_of(0, 0)(2, 2)(4, 0)(6, 2)(8, 0));
boost::geometry::assign_points(line3, line1 | boost::adaptors::filtered(x_between<int>(4, 8)));
std::cout << "line 1: " << boost::geometry::dsv(line1) << std::endl; std::cout << "line 2: " << boost::geometry::dsv(line2) << std::endl; std::cout << "line 3: " << boost::geometry::dsv(line3) << std::endl; return 0; }
| tuple_list_of is part of Boost.Assign and can be used for Boost.Geometry if points are tuples | |
| tuple_list_of delivers a range and can therefore be used in boost::geometry::assign | |
| Boost.Range adaptors can also be used in boost::geometry::assign | 
Output:
line 1: ((0, 0), (2, 3), (4, 0), (6, 3), (8, 0), (10, 3), (12, 0)) line 2: ((0, 0), (2, 2), (4, 0), (6, 2), (8, 0)) line 3: ((4, 0), (6, 3), (8, 0))