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 125