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_LCM_HPP_INCLUDED
13#define BOOST_MPL_LCM_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 lcm_impl;
39
40template< typename T > struct lcm_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 lcm
50 : lcm_impl<
51 typename lcm_tag<N1>::type
52 , typename lcm_tag<N2>::type
53 >::template apply<N1, N2>::type
54{
55 BOOST_MPL_AUX_LAMBDA_SUPPORT(2, lcm, (N1, N2))
56};
57
58BOOST_MPL_AUX_NA_SPEC(2, lcm)
59
60template<
61 typename T
62 , T n1
63 , T n2
64 >
65struct lcm_c
66 : lcm<integral_c<T,n1>,integral_c<T,n2> >
67{
68};
69
70
71namespace aux {
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 template< typename T1, boost::intmax_t n1, bool n1_is_0
77 , typename T2, boost::intmax_t n2, bool n2_is_0 >
78 struct lcm_aux
79 : abs<integral_c< typename aux::largest_int<T1, T2>::type,
80 ( n1 / gcd<integral_c<T1,n1>, integral_c<T2,n2> >::value * n2 )
81 > >
82 {};
83
84 template <typename T1, boost::intmax_t n1, typename T2, boost::intmax_t n2>
85 struct lcm_aux<T1, n1, false, T2, n2, true> : integral_c<T2, 0>
86 {};
87
88 template <typename T1, boost::intmax_t n1, typename T2, boost::intmax_t n2, bool C>
89 struct lcm_aux<T1, n1, true, T2, n2, C> : integral_c<T1, 0>
90 {};
91
92
93#else // defined(BOOST_MPL_CFG_NO_DEPENDENT_NONTYPE_PARAMETER_IN_PARTIAL_SPEC)
94
95
96 template< typename T1, T1 n1, bool n1_is_0, typename T2, T2 n2, bool n2_is_0 >
97 struct lcm_aux
98
99 : abs<integral_c< typename aux::largest_int<T1, T2>::type,
100 ( n1 / gcd<integral_c<T1,n1>, integral_c<T2,n2> >::value * n2 )
101 > >
102 {};
103
104 template <typename T1, T1 n1, typename T2, T2 n2>
105 struct lcm_aux<T1, n1, false, T2, n2, true> : integral_c<T2, 0>
106 {};
107
108 template <typename T1, T1 n1, typename T2, T2 n2, bool C>
109 struct lcm_aux<T1, n1, true, T2, n2, C> : integral_c<T1, 0>
110 {};
111#endif // defined(BOOST_MPL_CFG_NO_DEPENDENT_NONTYPE_PARAMETER_IN_PARTIAL_SPEC)
112}
113
114template<>
115struct lcm_impl<integral_c_tag, integral_c_tag>
116{
117 template< typename N1, typename N2 > struct apply
118 : abs<aux::lcm_aux< typename N1::value_type, N1::value, N1::value==0,
119 typename N2::value_type, N2::value, N2::value==0 > >
120 {
121 };
122};
123
124}}
125
126#endif // BOOST_MPL_LCM_HPP_INCLUDED
127