...one of the most highly
regarded and expertly designed C++ library projects in the
world.

— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards

set coordinate value of a Box / Segment

The free functions **get** and **set** are two of the most important functions of
Boost.Geometry, both within the library, as also for the library user.
With these two functions you normally get and set coordinate values from
and for a point, box, segment or sphere.

template<std::size_t Index, std::size_t Dimension, typename Geometry> void set(Geometry & geometry, typename coordinate_type< Geometry >::type const & value)

Type |
Concept |
Name |
Description |
---|---|---|---|

Index |
Index, this template parameter is required. For a Box: either min_corner or max_corner. For a Segment: either 0 or 1 for first or last point. |
- |
Must be specified |

Dimension |
Dimension, this template parameter is required. Should contain [0 .. n-1] for an n-dimensional geometry |
- |
Must be specified |

Geometry & |
Any type fulfilling a Box Concept or a Segment Concept |
geometry |
A model of the specified concept |

typename coordinate_type< Geometry >::type const & |
value |
The coordinate value to set |

Either

`#include <boost/geometry.hpp>`

Or

`#include <boost/geometry/core/access.hpp>`

Case |
Behavior |
---|---|

Box |
Sets the coordinate of a box (use min_corner, max_corner to specify which of the points to set) |

Segment |
Sets the coordinate of a segment (use 0, 1 to specify which of the two points to set) |

Constant

Set the coordinate of a box

#include <iostream> #include <boost/geometry.hpp> #include <boost/geometry/geometries/point_xy.hpp> namespace bg = boost::geometry; int main() { bg::model::box<bg::model::d2::point_xy<double> > box; bg::set<bg::min_corner, 0>(box, 0); bg::set<bg::min_corner, 1>(box, 2); bg::set<bg::max_corner, 0>(box, 4); bg::set<bg::max_corner, 1>(box, 5); std::cout << "Extent: " << bg::dsv(box) << std::endl; return 0; }

Output:

Extent: ((0, 2), (4, 5))