ceph/src/boost/libs/ratio/include/boost/ratio/detail/mpl/gcd.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_GCD_HPP_INCLUDED
  13 #define BOOST_MPL_GCD_HPP_INCLUDED
  14
  15 #include <boost/mpl/integral_c.hpp>
  16 #include <boost/ratio/detail/mpl/abs.hpp>
  17 #include <boost/mpl/aux_/largest_int.hpp>
  18 #include <boost/mpl/aux_/na_spec.hpp>
  19 #include <boost/mpl/aux_/lambda_support.hpp>
  20 #include <boost/mpl/aux_/config/integral.hpp>
  21 #include <boost/mpl/aux_/config/static_constant.hpp>
  22 #include <boost/mpl/aux_/config/dependent_nttp.hpp>
  23 #include <boost/cstdint.hpp>
  24
  25 #if    !defined(BOOST_MPL_CFG_NO_NESTED_VALUE_ARITHMETIC_2) \
  26     && !defined(BOOST_MPL_PREPROCESSING_MODE) \
  27     && !defined(__CUDACC__) \
  28     && ( defined(BOOST_MSVC) \
  29         || BOOST_WORKAROUND(__EDG_VERSION__, <= 238) \
  30         )
  31
  32 #   define BOOST_MPL_CFG_NO_NESTED_VALUE_ARITHMETIC_2
  33
  34 #endif
  35
  36 namespace boost { namespace mpl {
  37
  38 template< typename Tag1, typename Tag2 > struct gcd_impl;
  39
  40 template< typename T > struct gcd_tag
  41 {
  42     typedef typename T::tag type;
  43 };
  44
  45 template<
  46       typename BOOST_MPL_AUX_NA_PARAM(N1)
  47     , typename BOOST_MPL_AUX_NA_PARAM(N2)
  48     >
  49 struct gcd
  50     : gcd_impl<
  51           typename gcd_tag<N1>::type
  52         , typename gcd_tag<N2>::type
  53         >::template apply<N1, N2>::type
  54 {
  55     BOOST_MPL_AUX_LAMBDA_SUPPORT(2, gcd, (N1, N2))
  56 };
  57
  58 BOOST_MPL_AUX_NA_SPEC(2, gcd)
  59
  60 template<
  61       typename T
  62     , T n1
  63     , T n2
  64     >
  65 struct gcd_c
  66     : gcd<integral_c<T,n1>,integral_c<T,n2> >
  67 {
  68 };
  69
  70 namespace aux {
  71
  72   // Workaround for error: the type of partial specialization template parameter constant "n2"
  73     // depends on another template parameter
  74     // Note: this solution could be wrong for n1 or n2 = [2**63 .. 2**64-1]
  75 #if defined(BOOST_MPL_CFG_NO_DEPENDENT_NONTYPE_PARAMETER_IN_PARTIAL_SPEC)
  76
  77   template< typename T1, boost::intmax_t n1, bool n1_is_0
  78                   , typename T2, boost::intmax_t n2, bool n2_is_0 >
  79       struct gcd_aux
  80           : gcd_aux<T2, n2, n2==0, T1, (n1 % n2), (n1 % n2)==0>
  81       {};
  82
  83       template <typename T1, boost::intmax_t n1, typename T2, boost::intmax_t n2>
  84       struct gcd_aux<T1, n1, false, T2, n2, true> : integral_c<T1, n1>
  85       {};
  86
  87       template <typename T1, boost::intmax_t n1, typename T2, boost::intmax_t n2, bool C>
  88       struct gcd_aux<T1, n1, true, T2, n2, C> : integral_c<T2, n2>
  89       {};
  90
  91 #else // defined(BOOST_MPL_CFG_NO_DEPENDENT_NONTYPE_PARAMETER_IN_PARTIAL_SPEC)
  92
  93     template< typename T1, T1 n1, bool n1_is_0, typename T2, T2 n2, bool n2_is_0 >
  94     struct gcd_aux
  95
  96         : gcd_aux<T2, n2, n2==0,
  97                     typename aux::largest_int<T1, T2>::type,
  98                     //~ T1,
  99                     (n1 % n2), (n1 % n2)==0>
 100     {};
 101
 102     template <typename T1, T1 n1, typename T2, T2 n2>
 103     struct gcd_aux<T1, n1, false, T2, n2, true> : integral_c<T1, n1>
 104     {};
 105
 106     template <typename T1, T1 n1, typename T2, T2 n2, bool C>
 107     struct gcd_aux<T1, n1, true, T2, n2, C> : integral_c<T2, n2>
 108     {};
 109 #endif // defined(BOOST_MPL_CFG_NO_DEPENDENT_NONTYPE_PARAMETER_IN_PARTIAL_SPEC)
 110 }
 111
 112 template<>
 113 struct gcd_impl<integral_c_tag, integral_c_tag>
 114 {
 115     template< typename N1, typename N2 > struct apply
 116         : abs<aux::gcd_aux< typename N1::value_type, N1::value, N1::value==0,
 117                         typename N2::value_type, N2::value, N2::value==0  > >
 118     {
 119     };
 120 };
 121
 122 }}
 123
 124 #endif // BOOST_MPL_GCD_HPP_INCLUDED