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

   1 // Boost.Geometry (aka GGL, Generic Geometry Library)
   2
   3 // Copyright (c) 2007-2012 Barend Gehrels, Amsterdam, the Netherlands.
   4 // Copyright (c) 2008-2012 Bruno Lalande, Paris, France.
   5 // Copyright (c) 2009-2012 Mateusz Loskot, London, UK.
   6
   7 // Copyright (c) 2020 Oracle and/or its affiliates.
   8 // Contributed and/or modified by Adam Wulkiewicz, on behalf of Oracle
   9
  10 // Parts of Boost.Geometry are redesigned from Geodan's Geographic Library
  11 // (geolib/GGL), copyright (c) 1995-2010 Geodan, Amsterdam, the Netherlands.
  12
  13 // Use, modification and distribution is subject to the Boost Software License,
  14 // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
  15 // http://www.boost.org/LICENSE_1_0.txt)
  16
  17 #ifndef BOOST_GEOMETRY_UTIL_PARAMETER_TYPE_OF_HPP
  18 #define BOOST_GEOMETRY_UTIL_PARAMETER_TYPE_OF_HPP
  19
  20
  21 #include <type_traits>
  22
  23 #include <boost/function_types/function_arity.hpp>
  24 #include <boost/function_types/is_member_function_pointer.hpp>
  25 #include <boost/function_types/parameter_types.hpp>
  26
  27 #include <boost/mpl/at.hpp>
  28
  29
  30 namespace boost { namespace geometry
  31 {
  32
  33
  34 /*!
  35 \brief Meta-function selecting a parameter type of a (member) function, by index
  36 \ingroup utility
  37  */
  38 template <typename Method, std::size_t Index>
  39 struct parameter_type_of
  40 {
  41     typedef typename boost::function_types::parameter_types
  42         <
  43             Method
  44         >::type parameter_types;
  45
  46     typedef std::conditional_t
  47         <
  48             boost::function_types::is_member_function_pointer<Method>::value,
  49             std::integral_constant<int, 1>,
  50             std::integral_constant<int, 0>
  51         > base_index_type;
  52
  53     typedef std::conditional_t
  54         <
  55             Index == 0,
  56             base_index_type,
  57             std::integral_constant
  58                 <
  59                     int,
  60                     (base_index_type::value + Index)
  61                 >
  62         > indexed_type;
  63
  64     typedef typename std::remove_reference
  65         <
  66             typename boost::mpl::at
  67                 <
  68                     parameter_types,
  69                     indexed_type
  70                 >::type
  71         >::type type;
  72 };
  73
  74
  75 }} // namespace boost::geometry
  76
  77
  78 #endif // BOOST_GEOMETRY_UTIL_PARAMETER_TYPE_OF_HPP