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#### Boost.Tuple

Boost.Tuple tuples with arithmetic elements can be used as points within Boost.Geometry

###### Description

Boost.Tuple fixed sized collections, such as boost::tuple<double, double>, are (optionally) adapted to the Boost.Geometry point concept.

Boost.Tuple pairs or triples might have mutually different types, such as a boost::tuple<float, double>. Boost.Geometry reports the first type as its coordinate_type.

Boost.Geometry supports Boost.Tuple pairs, triples, quadruples, etc up to tuples with 10 elements (though most algorithms do not support so many dimensions).

A tuple can be the point type used by the models linestring, polygon, segment, box, and ring.

###### Model of

Point Concept

###### Header

`#include <boost/geometry/geometries/adapted/boost_tuple.hpp>`

The standard header `boost/geometry.hpp` does not include this header.

###### Example

Shows how to use Boost.Tuple points in Boost.Geometry

Working with Boost.Tuples in Boost.Geometry is straightforward and shown in various other examples as well.

    #include <iostream>

    #include <boost/geometry.hpp>
    #include <boost/geometry/geometries/polygon.hpp>
    #include <boost/geometry/geometries/adapted/boost_tuple.hpp>

    BOOST_GEOMETRY_REGISTER_BOOST_TUPLE_CS(cs::cartesian)

    int main()
    {
        boost::geometry::model::polygon<boost::tuple<double, double> > poly;
        poly.outer().push_back(boost::make_tuple(1.0, 2.0));
        poly.outer().push_back(boost::make_tuple(6.0, 4.0));
        poly.outer().push_back(boost::make_tuple(5.0, 1.0));
        poly.outer().push_back(boost::make_tuple(1.0, 2.0));

        std::cout << "Area: " << boost::geometry::area(poly) << std::endl;
        std::cout << "Contains (1.5, 2.5): "
            << std::boolalpha
            << boost::geometry::within(boost::make_tuple(1.5, 2.5), poly)
            << std::endl;

        return 0;
    }

Output:

    Area: 6.5
    Contains (1.5, 2.5): false