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

  Copyright (c) 2009-2012 Mateusz Loskot, London, UK.
  Copyright (c) 2009-2012 Barend Gehrels, Amsterdam, the Netherlands.
  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)
=============================================================================/]

[section:concept_point Point Concept]

[heading Description]
[concept Point..point]

A point is ['an entity that has a location in space or on a plane, but has no extent] ([@http://en.wikipedia.org/wiki/Point_(geometry) wiki]).
The point is the most basic geometry of Boost.Geometry, most other geometries consist of points. 
['(Exceptions are box and segment, which might consist of two points but that is not necessarily the case.)]

[heading Concept Definition]

The Point Concept is defined as following:

* there must be a specialization of `traits::tag`, defining `point_tag` as type
* there must be a specialization of `traits::coordinate_type`, defining the type of its coordinates
* there must be a specialization of `traits::coordinate_system`, defining its coordinate system
	 (cartesian, spherical, etc)
* there must be a specialization of `traits::dimension`, defining its number of dimensions (2, 3, ...) 
	(hint: derive it conveniently from `boost::mpl::int_<X>` for X Dimensional)
* there must be a specialization of `traits::access`, per dimension, with two functions:
	* `get` to get a coordinate value
	* `set` to set a coordinate value (this one is not checked for ConstPoint)
	
[heading Available Models]	
* [link geometry.reference.models.model_point model::point]
* [link geometry.reference.models.model_d2_point_xy model::d2::point_xy]
* a lat long point (currently in an extension)
* [link geometry.reference.adapted.c_array C array]
* [link geometry.reference.adapted.boost_array Boost.Array]
* [link geometry.reference.adapted.boost_fusion Boost.Fusion]
* [link geometry.reference.adapted.boost_polygon Boost.Polygon]
* [link geometry.reference.adapted.boost_tuple Boost.Tuple]
* other point types, adapted e.g. using one of the [link geometry.reference.adapted registration macro's]

[endsect]