ceph/src/boost/boost/geometry/util/transform_variant.hpp

   1 // Boost.Geometry (aka GGL, Generic Geometry Library)
   2
   3 // Copyright (c) 2007-2015 Barend Gehrels, Amsterdam, the Netherlands.
   4 // Copyright (c) 2008-2015 Bruno Lalande, Paris, France.
   5 // Copyright (c) 2009-2015 Mateusz Loskot, London, UK.
   6
   7 // This file was modified by Oracle on 2015.
   8 // Modifications copyright (c) 2015, Oracle and/or its affiliates.
   9
  10 // Contributed and/or modified by Menelaos Karavelas, on behalf of Oracle
  11
  12 // Parts of Boost.Geometry are redesigned from Geodan's Geographic Library
  13 // (geolib/GGL), copyright (c) 1995-2010 Geodan, Amsterdam, the Netherlands.
  14
  15 // Use, modification and distribution is subject to the Boost Software License,
  16 // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
  17 // http://www.boost.org/LICENSE_1_0.txt)
  18
  19 #ifndef BOOST_GEOMETRY_UTIL_TRANSFORM_VARIANT_HPP
  20 #define BOOST_GEOMETRY_UTIL_TRANSFORM_VARIANT_HPP
  21
  22
  23 #include <boost/mpl/transform.hpp>
  24 #include <boost/variant/variant_fwd.hpp>
  25
  26
  27 namespace boost { namespace geometry
  28 {
  29
  30
  31 /*!
  32     \brief Meta-function that takes a Sequence type, an MPL lambda
  33         expression and an optional Inserter and returns a variant type over
  34         the same types as the initial variant type, each transformed using
  35         the lambda expression.
  36     \ingroup utility
  37     \par Example
  38     \code
  39         typedef boost::mpl::vector<int, float, long> types;
  40         typedef transform_variant<types, add_pointer<_> > transformed;
  41         typedef variant<int*, float*, long*> result;
  42         BOOST_MPL_ASSERT(( equal<result, transformed> ));
  43     \endcode
  44 */
  45 template <typename Sequence, typename Op, typename In = boost::mpl::na>
  46 struct transform_variant:
  47     make_variant_over<
  48         typename boost::mpl::transform<
  49             Sequence,
  50             Op,
  51             In
  52         >::type
  53     >
  54 {};
  55
  56
  57 /*!
  58     \brief Meta-function that takes a boost::variant type and an MPL lambda
  59         expression and returns a variant type over the same types as the
  60         initial variant type, each transformed using the lambda expression.
  61     \ingroup utility
  62     \par Example
  63     \code
  64         typedef variant<int, float, long> variant_type;
  65         typedef transform_variant<variant_type, add_pointer<_> > transformed;
  66         typedef variant<int*, float*, long*> result;
  67         BOOST_MPL_ASSERT(( equal<result, transformed> ));
  68     \endcode
  69 */
  70 template <BOOST_VARIANT_ENUM_PARAMS(typename T), typename Op>
  71 struct transform_variant<variant<BOOST_VARIANT_ENUM_PARAMS(T)>, Op, boost::mpl::na> :
  72     make_variant_over<
  73         typename boost::mpl::transform<
  74             typename variant<BOOST_VARIANT_ENUM_PARAMS(T)>::types,
  75             Op
  76         >::type
  77     >
  78 {};
  79
  80
  81 }} // namespace boost::geometry
  82
  83
  84 #endif // BOOST_GEOMETRY_UTIL_TRANSFORM_VARIANT_HPP