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
36namespace boost { namespace mpl {
37
38template< typename Tag1, typename Tag2 > struct gcd_impl;
39
40template< typename T > struct gcd_tag
41{
42 typedef typename T::tag type;
43};
44
45template<
46 typename BOOST_MPL_AUX_NA_PARAM(N1)
47 , typename BOOST_MPL_AUX_NA_PARAM(N2)
48 >
49struct 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
58BOOST_MPL_AUX_NA_SPEC(2, gcd)
59
60template<
61 typename T
62 , T n1
63 , T n2
64 >
65struct gcd_c
66 : gcd<integral_c<T,n1>,integral_c<T,n2> >
67{
68};
69
70namespace 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
112template<>
113struct 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
125