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- // Boost.Geometry (aka GGL, Generic Geometry Library)
- // Copyright (c) 2007-2012 Barend Gehrels, Amsterdam, the Netherlands.
- // Copyright (c) 2008-2012 Bruno Lalande, Paris, France.
- // Copyright (c) 2009-2012 Mateusz Loskot, London, UK.
- // This file was modified by Oracle on 2014.
- // Modifications copyright (c) 2014 Oracle and/or its affiliates.
- // Contributed and/or modified by Adam Wulkiewicz, on behalf of Oracle
- // Parts of Boost.Geometry are redesigned from Geodan's Geographic Library
- // (geolib/GGL), copyright (c) 1995-2010 Geodan, Amsterdam, the Netherlands.
- // 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)
- #ifndef BOOST_GEOMETRY_UTIL_SELECT_CALCULATION_TYPE_HPP
- #define BOOST_GEOMETRY_UTIL_SELECT_CALCULATION_TYPE_HPP
- #include <boost/mpl/if.hpp>
- #include <boost/type_traits/is_void.hpp>
- #include <boost/geometry/util/select_coordinate_type.hpp>
- namespace boost { namespace geometry
- {
- /*!
- \brief Meta-function selecting the "calculation" type
- \details Based on two input geometry types, and an input calculation type,
- (which defaults to void in the calling function), this meta-function
- selects the most appropriate:
- - if calculation type is specified, that one is used,
- - if it is void, the most precise of the two points is used
- \ingroup utility
- */
- template <typename Geometry1, typename Geometry2, typename CalculationType>
- struct select_calculation_type
- {
- typedef typename
- boost::mpl::if_
- <
- boost::is_void<CalculationType>,
- typename select_coordinate_type
- <
- Geometry1,
- Geometry2
- >::type,
- CalculationType
- >::type type;
- };
- // alternative version supporting more than 2 Geometries
- template <typename CalculationType,
- typename Geometry1,
- typename Geometry2 = void,
- typename Geometry3 = void>
- struct select_calculation_type_alt
- {
- typedef typename
- boost::mpl::if_
- <
- boost::is_void<CalculationType>,
- typename select_coordinate_type
- <
- Geometry1,
- Geometry2,
- Geometry3
- >::type,
- CalculationType
- >::type type;
- };
- }} // namespace boost::geometry
- #endif // BOOST_GEOMETRY_UTIL_SELECT_CALCULATION_TYPE_HPP
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