Chris@102: //  Boost common_factor_ct.hpp header file  ----------------------------------//
Chris@102: 
Chris@102: //  (C) Copyright Daryle Walker and Stephen Cleary 2001-2002.
Chris@102: //  Distributed under the Boost Software License, Version 1.0. (See
Chris@102: //  accompanying file LICENSE_1_0.txt or copy at
Chris@102: //  http://www.boost.org/LICENSE_1_0.txt)
Chris@102: 
Chris@102: //  See http://www.boost.org for updates, documentation, and revision history. 
Chris@102: 
Chris@102: #ifndef BOOST_INTEGER_COMMON_FACTOR_CT_HPP
Chris@102: #define BOOST_INTEGER_COMMON_FACTOR_CT_HPP
Chris@102: 
Chris@102: #include <boost/integer_fwd.hpp>  // self include
Chris@102: #include <boost/config.hpp>  // for BOOST_STATIC_CONSTANT, etc.
Chris@102: 
Chris@102: namespace boost
Chris@102: {
Chris@102: namespace integer
Chris@102: {
Chris@102: 
Chris@102: //  Implementation details  --------------------------------------------------//
Chris@102: 
Chris@102: namespace detail
Chris@102: {
Chris@102:     // Build GCD with Euclid's recursive algorithm
Chris@102:     template < static_gcd_type Value1, static_gcd_type Value2 >
Chris@102:     struct static_gcd_helper_t
Chris@102:     {
Chris@102:     private:
Chris@102:         BOOST_STATIC_CONSTANT( static_gcd_type, new_value1 = Value2 );
Chris@102:         BOOST_STATIC_CONSTANT( static_gcd_type, new_value2 = Value1 % Value2 );
Chris@102: 
Chris@102:         #ifndef __BORLANDC__
Chris@102:         #define BOOST_DETAIL_GCD_HELPER_VAL(Value) static_cast<static_gcd_type>(Value)
Chris@102:         #else
Chris@102:         typedef static_gcd_helper_t  self_type;
Chris@102:         #define BOOST_DETAIL_GCD_HELPER_VAL(Value)  (self_type:: Value )
Chris@102:         #endif
Chris@102: 
Chris@102:         typedef static_gcd_helper_t< BOOST_DETAIL_GCD_HELPER_VAL(new_value1),
Chris@102:          BOOST_DETAIL_GCD_HELPER_VAL(new_value2) >  next_step_type;
Chris@102: 
Chris@102:         #undef BOOST_DETAIL_GCD_HELPER_VAL
Chris@102: 
Chris@102:     public:
Chris@102:         BOOST_STATIC_CONSTANT( static_gcd_type, value = next_step_type::value );
Chris@102:     };
Chris@102: 
Chris@102:     // Non-recursive case
Chris@102:     template < static_gcd_type Value1 >
Chris@102:     struct static_gcd_helper_t< Value1, 0UL >
Chris@102:     {
Chris@102:         BOOST_STATIC_CONSTANT( static_gcd_type, value = Value1 );
Chris@102:     };
Chris@102: 
Chris@102:     // Build the LCM from the GCD
Chris@102:     template < static_gcd_type Value1, static_gcd_type Value2 >
Chris@102:     struct static_lcm_helper_t
Chris@102:     {
Chris@102:         typedef static_gcd_helper_t<Value1, Value2>  gcd_type;
Chris@102: 
Chris@102:         BOOST_STATIC_CONSTANT( static_gcd_type, value = Value1 / gcd_type::value
Chris@102:          * Value2 );
Chris@102:     };
Chris@102: 
Chris@102:     // Special case for zero-GCD values
Chris@102:     template < >
Chris@102:     struct static_lcm_helper_t< 0UL, 0UL >
Chris@102:     {
Chris@102:         BOOST_STATIC_CONSTANT( static_gcd_type, value = 0UL );
Chris@102:     };
Chris@102: 
Chris@102: }  // namespace detail
Chris@102: 
Chris@102: 
Chris@102: //  Compile-time greatest common divisor evaluator class declaration  --------//
Chris@102: 
Chris@102: template < static_gcd_type Value1, static_gcd_type Value2 > struct static_gcd
Chris@102: {
Chris@102:     BOOST_STATIC_CONSTANT( static_gcd_type, value = (detail::static_gcd_helper_t<Value1, Value2>::value) );
Chris@102: };  // boost::integer::static_gcd
Chris@102: 
Chris@102: #if !defined(BOOST_NO_INCLASS_MEMBER_INITIALIZATION)
Chris@102: template< static_gcd_type Value1, static_gcd_type Value2 > static_gcd_type const static_gcd< Value1, Value2 >::value;
Chris@102: #endif
Chris@102: 
Chris@102: //  Compile-time least common multiple evaluator class declaration  ----------//
Chris@102: 
Chris@102: template < static_gcd_type Value1, static_gcd_type Value2 > struct static_lcm
Chris@102: {
Chris@102:     BOOST_STATIC_CONSTANT( static_gcd_type, value = (detail::static_lcm_helper_t<Value1, Value2>::value) );
Chris@102: };  // boost::integer::static_lcm
Chris@102: 
Chris@102: #if !defined(BOOST_NO_INCLASS_MEMBER_INITIALIZATION)
Chris@102: template< static_gcd_type Value1, static_gcd_type Value2 > static_gcd_type const static_lcm< Value1, Value2 >::value;
Chris@102: #endif
Chris@102: 
Chris@102: }  // namespace integer
Chris@102: }  // namespace boost
Chris@102: 
Chris@102: 
Chris@102: #endif  // BOOST_INTEGER_COMMON_FACTOR_CT_HPP