...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
template<typename Geometry, typename Type> Geometry make(Type const & c1, Type const & c2)
Type |
Concept |
Name |
Description |
---|---|---|---|
Geometry |
Any type fulfilling a Geometry Concept |
- |
Must be specified |
Type const & |
numerical type (int, double, ttmath, ...) to specify the coordinates |
c1 |
First coordinate (usually x-coordinate) |
Type const & |
numerical type (int, double, ttmath, ...) to specify the coordinates |
c2 |
Second coordinate (usually y-coordinate) |
The constructed geometry, here: a 2D point
Either
#include <boost/geometry.hpp>
Or
#include <boost/geometry/algorithms/make.hpp>
Shows the usage of make as a generic constructor for different point types
#include <iostream> #include <boost/geometry.hpp> #include <boost/geometry/geometries/point_xy.hpp> #include <boost/geometry/geometries/register/point.hpp> #include <boost/geometry/geometries/adapted/boost_tuple.hpp> #include <boost/geometry/geometries/adapted/boost_polygon/point.hpp> BOOST_GEOMETRY_REGISTER_BOOST_TUPLE_CS(cs::cartesian) struct mypoint { float _x, _y; }; BOOST_GEOMETRY_REGISTER_POINT_2D(mypoint, float, cs::cartesian, _x, _y) template <typename Point> void construct_and_display() { using boost::geometry::make; using boost::geometry::get; Point p = make<Point>(1, 2); std::cout << "x=" << get<0>(p) << " y=" << get<1>(p) << " (" << typeid(Point).name() << ")" << std::endl; } int main() { construct_and_display<boost::geometry::model::d2::point_xy<double> >(); construct_and_display<boost::geometry::model::d2::point_xy<int> >(); construct_and_display<boost::tuple<double, double> >(); construct_and_display<boost::polygon::point_data<int> >(); construct_and_display<mypoint>(); return 0; }
Output (compiled using gcc):
x=1 y=2 (N5boost8geometry5model2d28point_xyIdNS0_2cs9cartesianEEE) x=1 y=2 (N5boost8geometry5model2d28point_xyIiNS0_2cs9cartesianEEE) x=1 y=2 (N5boost6tuples5tupleIddNS0_9null_typeES2_S2_S2_S2_S2_S2_S2_EE) x=1 y=2 (N5boost7polygon10point_dataIiEE) x=1 y=2 (7mypoint)