ceph/src/boost/boost/geometry/util/add_const_if_c.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 // Parts of Boost.Geometry are redesigned from Geodan's Geographic Library
   8 // (geolib/GGL), copyright (c) 1995-2010 Geodan, Amsterdam, the Netherlands.
   9
  10 // Use, modification and distribution is subject to the Boost Software License,
  11 // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
  12 // http://www.boost.org/LICENSE_1_0.txt)
  13
  14 #ifndef BOOST_GEOMETRY_UTIL_ADD_CONST_IF_C_HPP
  15 #define BOOST_GEOMETRY_UTIL_ADD_CONST_IF_C_HPP
  16
  17
  18 #include <boost/mpl/if.hpp>
  19
  20
  21 namespace boost { namespace geometry
  22 {
  23
  24
  25 /*!
  26     \brief Meta-function to define a const or non const type
  27     \ingroup utility
  28     \details If the boolean template parameter is true, the type parameter
  29         will be defined as const, otherwise it will be defined as it was.
  30         This meta-function is used to have one implementation for both
  31         const and non const references
  32     \note This traits class is completely independant from Boost.Geometry
  33         and might be a separate addition to Boost
  34     \note Used in a.o. for_each, interior_rings, exterior_ring
  35     \par Example
  36     \code
  37         void foo(typename add_const_if_c<IsConst, Point>::type& point)
  38     \endcode
  39 */
  40 template <bool IsConst, typename Type>
  41 struct add_const_if_c
  42 {
  43     typedef typename boost::mpl::if_c
  44         <
  45             IsConst,
  46             Type const,
  47             Type
  48         >::type type;
  49 };
  50
  51
  52
  53 }} // namespace boost::geometry
  54
  55
  56 #endif // BOOST_GEOMETRY_UTIL_ADD_CONST_IF_C_HPP