// Boost common_factor_ct.hpp header file ----------------------------------// // (C) Copyright Daryle Walker and Stephen Cleary 2001-2002. // Distributed under the Boost Software License, Version 1.0. (See // accompanying file LICENSE_1_0.txt or copy at // http://www.boost.org/LICENSE_1_0.txt) // See http://www.boost.org for updates, documentation, and revision history. #ifndef BOOST_MATH_COMMON_FACTOR_CT_HPP #define BOOST_MATH_COMMON_FACTOR_CT_HPP #include <boost/math_fwd.hpp> // self include #include <boost/config.hpp> // for BOOST_STATIC_CONSTANT, etc. #include <boost/mpl/integral_c.hpp> namespace boost { namespace math { // Implementation details --------------------------------------------------// namespace detail { #ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION // Build GCD with Euclid's recursive algorithm template < static_gcd_type Value1, static_gcd_type Value2 > struct static_gcd_helper_t { private: BOOST_STATIC_CONSTANT( static_gcd_type, new_value1 = Value2 ); BOOST_STATIC_CONSTANT( static_gcd_type, new_value2 = Value1 % Value2 ); #ifndef __BORLANDC__ #define BOOST_DETAIL_GCD_HELPER_VAL(Value) static_cast<static_gcd_type>(Value) #else typedef static_gcd_helper_t self_type; #define BOOST_DETAIL_GCD_HELPER_VAL(Value) (self_type:: Value ) #endif typedef static_gcd_helper_t< BOOST_DETAIL_GCD_HELPER_VAL(new_value1), BOOST_DETAIL_GCD_HELPER_VAL(new_value2) > next_step_type; #undef BOOST_DETAIL_GCD_HELPER_VAL public: BOOST_STATIC_CONSTANT( static_gcd_type, value = next_step_type::value ); }; // Non-recursive case template < static_gcd_type Value1 > struct static_gcd_helper_t< Value1, 0UL > { BOOST_STATIC_CONSTANT( static_gcd_type, value = Value1 ); }; #else // Use inner class template workaround from Peter Dimov template < static_gcd_type Value1 > struct static_gcd_helper2_t { template < static_gcd_type Value2 > struct helper { BOOST_STATIC_CONSTANT( static_gcd_type, value = static_gcd_helper2_t<Value2>::BOOST_NESTED_TEMPLATE helper<Value1 % Value2>::value ); }; template < > struct helper< 0UL > { BOOST_STATIC_CONSTANT( static_gcd_type, value = Value1 ); }; }; // Special case template < > struct static_gcd_helper2_t< 0UL > { template < static_gcd_type Value2 > struct helper { BOOST_STATIC_CONSTANT( static_gcd_type, value = Value2 ); }; }; // Build the GCD from the above template(s) template < static_gcd_type Value1, static_gcd_type Value2 > struct static_gcd_helper_t { BOOST_STATIC_CONSTANT( static_gcd_type, value = static_gcd_helper2_t<Value1>::BOOST_NESTED_TEMPLATE helper<Value2>::value ); }; #endif #ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION // Build the LCM from the GCD template < static_gcd_type Value1, static_gcd_type Value2 > struct static_lcm_helper_t { typedef static_gcd_helper_t<Value1, Value2> gcd_type; BOOST_STATIC_CONSTANT( static_gcd_type, value = Value1 / gcd_type::value * Value2 ); }; // Special case for zero-GCD values template < > struct static_lcm_helper_t< 0UL, 0UL > { BOOST_STATIC_CONSTANT( static_gcd_type, value = 0UL ); }; #else // Adapt GCD's inner class template workaround for LCM template < static_gcd_type Value1 > struct static_lcm_helper2_t { template < static_gcd_type Value2 > struct helper { typedef static_gcd_helper_t<Value1, Value2> gcd_type; BOOST_STATIC_CONSTANT( static_gcd_type, value = Value1 / gcd_type::value * Value2 ); }; template < > struct helper< 0UL > { BOOST_STATIC_CONSTANT( static_gcd_type, value = 0UL ); }; }; // Special case template < > struct static_lcm_helper2_t< 0UL > { template < static_gcd_type Value2 > struct helper { BOOST_STATIC_CONSTANT( static_gcd_type, value = 0UL ); }; }; // Build the LCM from the above template(s) template < static_gcd_type Value1, static_gcd_type Value2 > struct static_lcm_helper_t { BOOST_STATIC_CONSTANT( static_gcd_type, value = static_lcm_helper2_t<Value1>::BOOST_NESTED_TEMPLATE helper<Value2>::value ); }; #endif } // namespace detail // Compile-time greatest common divisor evaluator class declaration --------// template < static_gcd_type Value1, static_gcd_type Value2 > struct static_gcd : public mpl::integral_c<static_gcd_type, (detail::static_gcd_helper_t<Value1, Value2>::value) > { }; // boost::math::static_gcd // Compile-time least common multiple evaluator class declaration ----------// template < static_gcd_type Value1, static_gcd_type Value2 > struct static_lcm : public mpl::integral_c<static_gcd_type, (detail::static_lcm_helper_t<Value1, Value2>::value) > { }; // boost::math::static_lcm } // namespace math } // namespace boost #endif // BOOST_MATH_COMMON_FACTOR_CT_HPP