ceph/src/boost/boost/ratio/detail/mpl/sign.hpp

   1 ////////////////////////////////////////////////////////////////////
   2 //
   3 // Copyright Vicente J. Botet Escriba 2010
   4 //
   5 // Distributed under the Boost Software License, Version 1.0.
   6 // (See accompanying file LICENSE_1_0.txt or copy at
   7 // http://www.boost.org/LICENSE_1_0.txt)
   8 //
   9 // See http://www.boost.org/libs/mpl for documentation.
  10 //
  11 ////////////////////////////////////////////////////////////////////
  12 #ifndef BOOST_MPL_SIGN_HPP_INCLUDED
  13 #define BOOST_MPL_SIGN_HPP_INCLUDED
  14
  15 #include <boost/mpl/integral_c.hpp>
  16 #include <boost/mpl/aux_/na_spec.hpp>
  17 #include <boost/mpl/aux_/lambda_support.hpp>
  18 #include <boost/mpl/aux_/config/integral.hpp>
  19 #include <boost/mpl/aux_/config/static_constant.hpp>
  20
  21 #if    !defined(BOOST_MPL_CFG_NO_NESTED_VALUE_ARITHMETIC_2) \
  22     && !defined(BOOST_MPL_PREPROCESSING_MODE) \
  23     && !defined(__CUDACC__) \
  24     && ( defined(BOOST_MSVC) \
  25         || BOOST_WORKAROUND(__EDG_VERSION__, <= 238) \
  26         )
  27
  28 #   define BOOST_MPL_CFG_NO_NESTED_VALUE_ARITHMETIC_2
  29
  30 #endif
  31
  32 namespace boost { namespace mpl {
  33
  34 template< typename Tag > struct sign_impl;
  35
  36 template< typename T > struct sign_tag
  37 {
  38     typedef typename T::tag type;
  39 };
  40
  41 template<
  42       typename BOOST_MPL_AUX_NA_PARAM(N)
  43     >
  44 struct sign
  45     : sign_impl<
  46           typename sign_tag<N>::type
  47         >::template apply<N>::type
  48 {
  49     BOOST_MPL_AUX_LAMBDA_SUPPORT(1, sign, (N))
  50 };
  51
  52 BOOST_MPL_AUX_NA_SPEC(1, sign)
  53
  54 template<
  55       typename T
  56     , T n1
  57     >
  58 struct sign_c
  59     : sign<integral_c<T,n1> >
  60 {
  61 };
  62
  63 #if defined(BOOST_MPL_CFG_NO_NESTED_VALUE_ARITHMETIC_2)
  64 namespace aux {
  65 template< typename T, T n > struct sign_wknd
  66 {
  67     BOOST_STATIC_CONSTANT(T, value = (n == 0 ? 0 : (n < 0 ? -1 : 1)));
  68     typedef integral_c<T,value> type;
  69 };
  70 }
  71 #endif
  72
  73 template<>
  74 struct sign_impl<integral_c_tag>
  75 {
  76 #if defined(BOOST_MPL_CFG_NO_NESTED_VALUE_ARITHMETIC_2)
  77     template< typename N > struct apply
  78         : aux::sign_wknd< typename N::value_type, N::value >
  79 #else
  80     template< typename N > struct apply
  81         : integral_c< typename N::value_type, (N::value == 0 ? 0 : (N::value < 0 ? -1 : 1)) >
  82 #endif
  83     {
  84     };
  85 };
  86
  87 }}
  88
  89 #endif // BOOST_MPL_SIGN_HPP_INCLUDED