294 lines
		
	
	
		
			8.7 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
		
		
			
		
	
	
			294 lines
		
	
	
		
			8.7 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
|   | //  ratio.hpp  ---------------------------------------------------------------//
 | ||
|  | 
 | ||
|  | //  Copyright 2008 Howard Hinnant
 | ||
|  | //  Copyright 2008 Beman Dawes
 | ||
|  | //  Copyright 2009 Vicente J. Botet Escriba
 | ||
|  | 
 | ||
|  | //  Distributed under the Boost Software License, Version 1.0.
 | ||
|  | //  See http://www.boost.org/LICENSE_1_0.txt
 | ||
|  | 
 | ||
|  | /*
 | ||
|  | 
 | ||
|  | This code was derived by Beman Dawes from Howard Hinnant's time2_demo prototype. | ||
|  | Many thanks to Howard for making his code available under the Boost license. | ||
|  | The original code was modified to conform to Boost conventions and to section | ||
|  | 20.4 Compile-time rational arithmetic [ratio], of the C++ committee working | ||
|  | paper N2798. | ||
|  | See http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2798.pdf.
 | ||
|  | 
 | ||
|  | time2_demo contained this comment: | ||
|  | 
 | ||
|  |     Much thanks to Andrei Alexandrescu, | ||
|  |                    Walter Brown, | ||
|  |                    Peter Dimov, | ||
|  |                    Jeff Garland, | ||
|  |                    Terry Golubiewski, | ||
|  |                    Daniel Krugler, | ||
|  |                    Anthony Williams. | ||
|  | */ | ||
|  | 
 | ||
|  | // The way overflow is managed for ratio_less is taken from llvm/libcxx/include/ratio
 | ||
|  | 
 | ||
|  | #ifndef BOOST_RATIO_RATIO_HPP
 | ||
|  | #define BOOST_RATIO_RATIO_HPP
 | ||
|  | 
 | ||
|  | #include <boost/ratio/config.hpp>
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|  | #include <boost/ratio/detail/mpl/abs.hpp>
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|  | #include <boost/ratio/detail/mpl/sign.hpp>
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|  | #include <boost/ratio/detail/mpl/gcd.hpp>
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|  | #include <boost/ratio/detail/mpl/lcm.hpp>
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|  | #include <cstdlib>
 | ||
|  | #include <climits>
 | ||
|  | #include <limits>
 | ||
|  | #include <boost/cstdint.hpp>
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|  | #include <boost/type_traits/integral_constant.hpp>
 | ||
|  | #include <boost/core/enable_if.hpp>
 | ||
|  | #include <boost/integer_traits.hpp>
 | ||
|  | #include <boost/ratio/ratio_fwd.hpp>
 | ||
|  | #include <boost/ratio/detail/overflow_helpers.hpp>
 | ||
|  | #ifdef BOOST_RATIO_EXTENSIONS
 | ||
|  | #include <boost/rational.hpp>
 | ||
|  | #include <boost/ratio/mpl/rational_c_tag.hpp>
 | ||
|  | #endif
 | ||
|  | 
 | ||
|  | //
 | ||
|  | // We simply cannot include this header on gcc without getting copious warnings of the kind:
 | ||
|  | //
 | ||
|  | // boost/integer.hpp:77:30: warning: use of C99 long long integer constant
 | ||
|  | //
 | ||
|  | // And yet there is no other reasonable implementation, so we declare this a system header
 | ||
|  | // to suppress these warnings.
 | ||
|  | //
 | ||
|  | #if defined(__GNUC__) && (__GNUC__ >= 4)
 | ||
|  | #pragma GCC system_header
 | ||
|  | #endif
 | ||
|  | 
 | ||
|  | namespace boost | ||
|  | { | ||
|  | 
 | ||
|  | 
 | ||
|  | //----------------------------------------------------------------------------//
 | ||
|  | //                                                                            //
 | ||
|  | //                20.6.1 Class template ratio [ratio.ratio]                   //
 | ||
|  | //                                                                            //
 | ||
|  | //----------------------------------------------------------------------------//
 | ||
|  | 
 | ||
|  | template <boost::intmax_t N, boost::intmax_t D> | ||
|  | class ratio | ||
|  | { | ||
|  |     static const boost::intmax_t ABS_N = mpl::abs_c<boost::intmax_t, N>::value; | ||
|  |     static const boost::intmax_t ABS_D = mpl::abs_c<boost::intmax_t, D>::value; | ||
|  |     BOOST_RATIO_STATIC_ASSERT(ABS_N >= 0, BOOST_RATIO_NUMERATOR_IS_OUT_OF_RANGE, ()); | ||
|  |     BOOST_RATIO_STATIC_ASSERT(ABS_D > 0, BOOST_RATIO_DENOMINATOR_IS_OUT_OF_RANGE, ()); | ||
|  |     BOOST_RATIO_STATIC_ASSERT(D != 0, BOOST_RATIO_DIVIDE_BY_0 , ()); | ||
|  |     static const boost::intmax_t SIGN_N = mpl::sign_c<boost::intmax_t,N>::value | ||
|  |       * mpl::sign_c<boost::intmax_t,D>::value; | ||
|  |     static const boost::intmax_t GCD = mpl::gcd_c<boost::intmax_t, ABS_N, ABS_D>::value; | ||
|  | public: | ||
|  |     BOOST_STATIC_CONSTEXPR boost::intmax_t num = SIGN_N * ABS_N / GCD; | ||
|  |     BOOST_STATIC_CONSTEXPR boost::intmax_t den = ABS_D / GCD; | ||
|  | 
 | ||
|  | #ifdef BOOST_RATIO_EXTENSIONS
 | ||
|  |     typedef mpl::rational_c_tag tag; | ||
|  |     typedef boost::rational<boost::intmax_t> value_type; | ||
|  |     typedef boost::intmax_t num_type; | ||
|  |     typedef boost::intmax_t den_type; | ||
|  |     ratio() | ||
|  |     {} | ||
|  |     template <boost::intmax_t _N2, boost::intmax_t _D2> | ||
|  |     ratio(const ratio<_N2, _D2>&, | ||
|  |         typename enable_if_c | ||
|  |             < | ||
|  |                 (ratio<_N2, _D2>::num == num && | ||
|  |                 ratio<_N2, _D2>::den == den) | ||
|  |             >::type* = 0) | ||
|  |     {} | ||
|  | 
 | ||
|  |     template <boost::intmax_t _N2, boost::intmax_t _D2> | ||
|  |         typename enable_if_c | ||
|  |         < | ||
|  |             (ratio<_N2, _D2>::num == num && | ||
|  |             ratio<_N2, _D2>::den == den), | ||
|  |             ratio& | ||
|  |         >::type | ||
|  |     operator=(const ratio<_N2, _D2>&) {return *this;} | ||
|  | 
 | ||
|  |     static value_type value() {return value_type(num,den);} | ||
|  |     value_type operator()() const {return value();} | ||
|  | #endif
 | ||
|  |     typedef ratio<num, den> type; | ||
|  | }; | ||
|  | 
 | ||
|  | #if defined(BOOST_NO_CXX11_CONSTEXPR)
 | ||
|  | template <boost::intmax_t N, boost::intmax_t D> | ||
|  | const    boost::intmax_t ratio<N, D>::num; | ||
|  | template <boost::intmax_t N, boost::intmax_t D> | ||
|  | const    boost::intmax_t ratio<N, D>::den; | ||
|  | #endif
 | ||
|  | 
 | ||
|  | //----------------------------------------------------------------------------//
 | ||
|  | //                                                                            //
 | ||
|  | //                20.6.2 Arithmetic on ratio types [ratio.arithmetic]         //
 | ||
|  | //                                                                            //
 | ||
|  | //----------------------------------------------------------------------------//
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|  | 
 | ||
|  | template <class R1, class R2> | ||
|  | struct ratio_add | ||
|  | : boost::ratio_detail::ratio_add<R1, R2>::type | ||
|  | { | ||
|  | }; | ||
|  | 
 | ||
|  | template <class R1, class R2> | ||
|  | struct ratio_subtract | ||
|  | : boost::ratio_detail::ratio_subtract<R1, R2>::type | ||
|  | { | ||
|  | }; | ||
|  | 
 | ||
|  | template <class R1, class R2> | ||
|  | struct ratio_multiply | ||
|  | : boost::ratio_detail::ratio_multiply<R1, R2>::type | ||
|  | { | ||
|  | }; | ||
|  | 
 | ||
|  | template <class R1, class R2> | ||
|  | struct ratio_divide | ||
|  | : boost::ratio_detail::ratio_divide<R1, R2>::type | ||
|  | { | ||
|  | }; | ||
|  | 
 | ||
|  | //----------------------------------------------------------------------------//
 | ||
|  | //                                                                            //
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|  | //                20.6.3 Comparision of ratio types [ratio.comparison]        //
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|  | //                                                                            //
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|  | //----------------------------------------------------------------------------//
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|  | 
 | ||
|  | // ratio_equal
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|  | 
 | ||
|  | template <class R1, class R2> | ||
|  | struct ratio_equal | ||
|  |     : public boost::integral_constant<bool, | ||
|  |                                (R1::num == R2::num && R1::den == R2::den)> | ||
|  | {}; | ||
|  | 
 | ||
|  | template <class R1, class R2> | ||
|  | struct ratio_not_equal | ||
|  |     : public boost::integral_constant<bool, !ratio_equal<R1, R2>::value> | ||
|  | {}; | ||
|  | 
 | ||
|  | // ratio_less
 | ||
|  | 
 | ||
|  | template <class R1, class R2> | ||
|  | struct ratio_less | ||
|  |     : boost::integral_constant<bool, boost::ratio_detail::ratio_less<R1, R2>::value> | ||
|  | {}; | ||
|  | 
 | ||
|  | template <class R1, class R2> | ||
|  | struct ratio_less_equal | ||
|  |     : boost::integral_constant<bool, !ratio_less<R2, R1>::value> | ||
|  | {}; | ||
|  | 
 | ||
|  | template <class R1, class R2> | ||
|  | struct ratio_greater | ||
|  |     : boost::integral_constant<bool, ratio_less<R2, R1>::value> | ||
|  | {}; | ||
|  | 
 | ||
|  | template <class R1, class R2> | ||
|  | struct ratio_greater_equal | ||
|  |     : boost::integral_constant<bool, !ratio_less<R1, R2>::value> | ||
|  | {}; | ||
|  | 
 | ||
|  | template <class R1, class R2> | ||
|  | struct ratio_gcd : | ||
|  |     ratio<mpl::gcd_c<boost::intmax_t, R1::num, R2::num>::value, | ||
|  |         mpl::lcm_c<boost::intmax_t, R1::den, R2::den>::value>::type | ||
|  | { | ||
|  | }; | ||
|  | 
 | ||
|  |     //----------------------------------------------------------------------------//
 | ||
|  |     //                                                                            //
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|  |     //                More arithmetic on ratio types [ratio.arithmetic]           //
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|  |     //                                                                            //
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|  |     //----------------------------------------------------------------------------//
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|  | 
 | ||
|  | #ifdef BOOST_RATIO_EXTENSIONS
 | ||
|  | template <class R> | ||
|  | struct ratio_negate | ||
|  |     : ratio<-R::num, R::den>::type | ||
|  | { | ||
|  | }; | ||
|  | template <class R> | ||
|  | struct ratio_abs | ||
|  |     : ratio<mpl::abs_c<boost::intmax_t, R::num>::value, R::den>::type | ||
|  | { | ||
|  | }; | ||
|  | template <class R> | ||
|  | struct ratio_sign | ||
|  |     : mpl::sign_c<boost::intmax_t, R::num> | ||
|  | { | ||
|  | }; | ||
|  | 
 | ||
|  | template <class R> | ||
|  | struct ratio_inverse | ||
|  |     : ratio<R::den, R::num>::type | ||
|  | { | ||
|  | }; | ||
|  | 
 | ||
|  | 
 | ||
|  | template <class R1, class R2> | ||
|  | struct ratio_lcm : | ||
|  |     ratio<mpl::lcm_c<boost::intmax_t, R1::num, R2::num>::value, | ||
|  |         mpl::gcd_c<boost::intmax_t, R1::den, R2::den>::value>::type | ||
|  | { | ||
|  | }; | ||
|  | 
 | ||
|  | template <class R1, class R2> | ||
|  | struct ratio_modulo : | ||
|  |     ratio<(R1::num * R2::den) % (R2::num * R1::den), R1::den * R2::den>::type | ||
|  | { | ||
|  | }; | ||
|  | 
 | ||
|  | namespace detail { | ||
|  |   template <class R1, class R2, bool r1ltr2> | ||
|  |   struct ratio_min : R1 {}; | ||
|  |   template <class R1, class R2> | ||
|  |   struct ratio_min<R1,R2,false> : R2 {}; | ||
|  | 
 | ||
|  |   template <class R1, class R2, bool r1ltr2> | ||
|  |   struct ratio_max : R2 {}; | ||
|  |   template <class R1, class R2> | ||
|  |   struct ratio_max<R1,R2,false> : R1 {}; | ||
|  | } | ||
|  | 
 | ||
|  | template <class R1, class R2> | ||
|  | struct ratio_min : detail::ratio_min<R1, R2, ratio_less<R1,R2>::value>::type | ||
|  | { | ||
|  | }; | ||
|  | 
 | ||
|  | template <class R1, class R2> | ||
|  | struct ratio_max : detail::ratio_max<R1, R2, ratio_less<R1,R2>::value>::type | ||
|  | { | ||
|  | }; | ||
|  | 
 | ||
|  | template<typename R, int p> | ||
|  | struct ratio_power : | ||
|  |   ratio_multiply< | ||
|  |     typename ratio_power<R, p%2>::type, | ||
|  |     typename ratio_power<typename ratio_multiply<R, R>::type, p/2>::type | ||
|  |   >::type | ||
|  | {}; | ||
|  | 
 | ||
|  | template<typename R> | ||
|  | struct ratio_power<R, 0> : ratio<1>::type {}; | ||
|  | 
 | ||
|  | template<typename R> | ||
|  | struct ratio_power<R, 1> : R {}; | ||
|  | 
 | ||
|  | template<typename R> | ||
|  | struct ratio_power<R, -1> : ratio_divide<ratio<1>, R>::type {}; | ||
|  | 
 | ||
|  | #endif
 | ||
|  | }  // namespace boost
 | ||
|  | 
 | ||
|  | 
 | ||
|  | #endif  // BOOST_RATIO_RATIO_HPP
 |