[/============================================================================
  Boost.Geometry (aka GGL, Generic Geometry Library)

  Copyright (c) 2009-2012 Barend Gehrels, Amsterdam, the Netherlands.
  Copyright (c) 2009-2012 Mateusz Loskot, London, UK.
  Copyright (c) 2009-2012 Bruno Lalande, Paris, France.

  Use, modification and distribution is subject to the Boost Software License,
  Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
  http://www.boost.org/LICENSE_1_0.txt)
=============================================================================/]

[def __this_function__ union]

[heading_conformance_ogc __this_function__..Union]
[note __boost_geometry__ adds an underscore to avoid using the `union` keyword]

[heading Behavior]
[table
[[Case] [Behavior] ]
[[[qbk_out __polygon__]][Calculates union polygons of input (multi)polygons and/or boxes]]
]

[include reference/algorithms/geometry_rules.qbk]

[heading Example]
[union]
[union_output]

[heading See also]
* [link geometry.reference.algorithms.intersection intersection]
* [link geometry.reference.algorithms.difference difference]
* [link geometry.reference.algorithms.sym_difference sym_difference (symmetric difference)]