ceph/src/boost/boost/mpl/aux_/na.hpp

   1
   2 #ifndef BOOST_MPL_AUX_NA_HPP_INCLUDED
   3 #define BOOST_MPL_AUX_NA_HPP_INCLUDED
   4
   5 // Copyright Aleksey Gurtovoy 2001-2004
   6 //
   7 // Distributed under the Boost Software License, Version 1.0.
   8 // (See accompanying file LICENSE_1_0.txt or copy at
   9 // http://www.boost.org/LICENSE_1_0.txt)
  10 //
  11 // See http://www.boost.org/libs/mpl for documentation.
  12
  13 // $Id$
  14 // $Date$
  15 // $Revision$
  16
  17 #include <boost/mpl/bool.hpp>
  18 #include <boost/mpl/aux_/na_fwd.hpp>
  19 #include <boost/mpl/aux_/config/msvc.hpp>
  20 #include <boost/mpl/aux_/config/ctps.hpp>
  21
  22 namespace boost { namespace mpl {
  23
  24 template< typename T >
  25 struct is_na
  26     : false_
  27 {
  28 #if BOOST_WORKAROUND(BOOST_MSVC, < 1300)
  29     using false_::value;
  30 #endif
  31 };
  32
  33 template<>
  34 struct is_na<na>
  35     : true_
  36 {
  37 #if BOOST_WORKAROUND(BOOST_MSVC, < 1300)
  38     using true_::value;
  39 #endif
  40 };
  41
  42 template< typename T >
  43 struct is_not_na
  44     : true_
  45 {
  46 #if BOOST_WORKAROUND(BOOST_MSVC, < 1300)
  47     using true_::value;
  48 #endif
  49 };
  50
  51 template<>
  52 struct is_not_na<na>
  53     : false_
  54 {
  55 #if BOOST_WORKAROUND(BOOST_MSVC, < 1300)
  56     using false_::value;
  57 #endif
  58 };
  59
  60 #if !defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION)
  61 template< typename T, typename U > struct if_na
  62 {
  63     typedef T type;
  64 };
  65
  66 template< typename U > struct if_na<na,U>
  67 {
  68     typedef U type;
  69 };
  70 #else
  71 template< typename T > struct if_na_impl
  72 {
  73     template< typename U > struct apply
  74     {
  75         typedef T type;
  76     };
  77 };
  78
  79 template<> struct if_na_impl<na>
  80 {
  81     template< typename U > struct apply
  82     {
  83         typedef U type;
  84     };
  85 };
  86
  87 template< typename T, typename U > struct if_na
  88     : if_na_impl<T>::template apply<U>
  89 {
  90 };
  91 #endif
  92
  93 }}
  94
  95 #endif // BOOST_MPL_AUX_NA_HPP_INCLUDED