Chris@16: //  ratio.hpp  ---------------------------------------------------------------//
Chris@16: 
Chris@16: //  Copyright 2008 Howard Hinnant
Chris@16: //  Copyright 2008 Beman Dawes
Chris@16: //  Copyright 2009 Vicente J. Botet Escriba
Chris@16: 
Chris@16: //  Distributed under the Boost Software License, Version 1.0.
Chris@16: //  See http://www.boost.org/LICENSE_1_0.txt
Chris@16: 
Chris@16: /*
Chris@16: 
Chris@16: This code was derived by Beman Dawes from Howard Hinnant's time2_demo prototype.
Chris@16: Many thanks to Howard for making his code available under the Boost license.
Chris@16: The original code was modified to conform to Boost conventions and to section
Chris@16: 20.4 Compile-time rational arithmetic [ratio], of the C++ committee working
Chris@16: paper N2798.
Chris@16: See http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2798.pdf.
Chris@16: 
Chris@16: time2_demo contained this comment:
Chris@16: 
Chris@16:     Much thanks to Andrei Alexandrescu,
Chris@16:                    Walter Brown,
Chris@16:                    Peter Dimov,
Chris@16:                    Jeff Garland,
Chris@16:                    Terry Golubiewski,
Chris@16:                    Daniel Krugler,
Chris@16:                    Anthony Williams.
Chris@16: */
Chris@16: 
Chris@16: // The way overflow is managed for ratio_less is taken from llvm/libcxx/include/ratio
Chris@16: 
Chris@16: #ifndef BOOST_RATIO_RATIO_HPP
Chris@16: #define BOOST_RATIO_RATIO_HPP
Chris@16: 
Chris@16: #include <boost/ratio/config.hpp>
Chris@16: #include <boost/ratio/detail/mpl/abs.hpp>
Chris@16: #include <boost/ratio/detail/mpl/sign.hpp>
Chris@16: #include <boost/ratio/detail/mpl/gcd.hpp>
Chris@16: #include <boost/ratio/detail/mpl/lcm.hpp>
Chris@16: #include <cstdlib>
Chris@16: #include <climits>
Chris@16: #include <limits>
Chris@16: #include <boost/cstdint.hpp>
Chris@16: #include <boost/type_traits/integral_constant.hpp>
Chris@101: #include <boost/core/enable_if.hpp>
Chris@16: #include <boost/integer_traits.hpp>
Chris@16: #include <boost/ratio/ratio_fwd.hpp>
Chris@16: #include <boost/ratio/detail/overflow_helpers.hpp>
Chris@16: #ifdef BOOST_RATIO_EXTENSIONS
Chris@16: #include <boost/rational.hpp>
Chris@16: #include <boost/ratio/mpl/rational_c_tag.hpp>
Chris@16: #endif
Chris@16: 
Chris@16: //
Chris@16: // We simply cannot include this header on gcc without getting copious warnings of the kind:
Chris@16: //
Chris@16: // boost/integer.hpp:77:30: warning: use of C99 long long integer constant
Chris@16: //
Chris@16: // And yet there is no other reasonable implementation, so we declare this a system header
Chris@16: // to suppress these warnings.
Chris@16: //
Chris@16: #if defined(__GNUC__) && (__GNUC__ >= 4)
Chris@16: #pragma GCC system_header
Chris@16: #endif
Chris@16: 
Chris@16: namespace boost
Chris@16: {
Chris@16: 
Chris@16: 
Chris@16: //----------------------------------------------------------------------------//
Chris@16: //                                                                            //
Chris@16: //                20.6.1 Class template ratio [ratio.ratio]                   //
Chris@16: //                                                                            //
Chris@16: //----------------------------------------------------------------------------//
Chris@16: 
Chris@16: template <boost::intmax_t N, boost::intmax_t D>
Chris@16: class ratio
Chris@16: {
Chris@16:     static const boost::intmax_t ABS_N = mpl::abs_c<boost::intmax_t, N>::value;
Chris@16:     static const boost::intmax_t ABS_D = mpl::abs_c<boost::intmax_t, D>::value;
Chris@16:     BOOST_RATIO_STATIC_ASSERT(ABS_N >= 0, BOOST_RATIO_NUMERATOR_IS_OUT_OF_RANGE, ());
Chris@16:     BOOST_RATIO_STATIC_ASSERT(ABS_D > 0, BOOST_RATIO_DENOMINATOR_IS_OUT_OF_RANGE, ());
Chris@16:     BOOST_RATIO_STATIC_ASSERT(D != 0, BOOST_RATIO_DIVIDE_BY_0 , ());
Chris@16:     static const boost::intmax_t SIGN_N = mpl::sign_c<boost::intmax_t,N>::value
Chris@16:       * mpl::sign_c<boost::intmax_t,D>::value;
Chris@16:     static const boost::intmax_t GCD = mpl::gcd_c<boost::intmax_t, ABS_N, ABS_D>::value;
Chris@16: public:
Chris@16:     BOOST_STATIC_CONSTEXPR boost::intmax_t num = SIGN_N * ABS_N / GCD;
Chris@16:     BOOST_STATIC_CONSTEXPR boost::intmax_t den = ABS_D / GCD;
Chris@16: 
Chris@16: #ifdef BOOST_RATIO_EXTENSIONS
Chris@16:     typedef mpl::rational_c_tag tag;
Chris@16:     typedef boost::rational<boost::intmax_t> value_type;
Chris@16:     typedef boost::intmax_t num_type;
Chris@16:     typedef boost::intmax_t den_type;
Chris@16:     ratio()
Chris@16:     {}
Chris@16:     template <boost::intmax_t _N2, boost::intmax_t _D2>
Chris@16:     ratio(const ratio<_N2, _D2>&,
Chris@16:         typename enable_if_c
Chris@16:             <
Chris@16:                 (ratio<_N2, _D2>::num == num &&
Chris@16:                 ratio<_N2, _D2>::den == den)
Chris@16:             >::type* = 0)
Chris@16:     {}
Chris@16: 
Chris@16:     template <boost::intmax_t _N2, boost::intmax_t _D2>
Chris@16:         typename enable_if_c
Chris@16:         <
Chris@16:             (ratio<_N2, _D2>::num == num &&
Chris@16:             ratio<_N2, _D2>::den == den),
Chris@16:             ratio&
Chris@16:         >::type
Chris@16:     operator=(const ratio<_N2, _D2>&) {return *this;}
Chris@16: 
Chris@16:     static value_type value() {return value_type(num,den);}
Chris@16:     value_type operator()() const {return value();}
Chris@16: #endif
Chris@16:     typedef ratio<num, den> type;
Chris@16: };
Chris@16: 
Chris@16: #if defined(BOOST_NO_CXX11_CONSTEXPR)
Chris@16: template <boost::intmax_t N, boost::intmax_t D>
Chris@16: const    boost::intmax_t ratio<N, D>::num;
Chris@16: template <boost::intmax_t N, boost::intmax_t D>
Chris@16: const    boost::intmax_t ratio<N, D>::den;
Chris@16: #endif
Chris@16: 
Chris@16: //----------------------------------------------------------------------------//
Chris@16: //                                                                            //
Chris@101: //                20.6.2 Arithmetic on ratio types [ratio.arithmetic]         //
Chris@16: //                                                                            //
Chris@16: //----------------------------------------------------------------------------//
Chris@16: 
Chris@16: template <class R1, class R2>
Chris@16: struct ratio_add
Chris@16: : boost::ratio_detail::ratio_add<R1, R2>::type
Chris@16: {
Chris@16: };
Chris@16: 
Chris@16: template <class R1, class R2>
Chris@16: struct ratio_subtract
Chris@16: : boost::ratio_detail::ratio_subtract<R1, R2>::type
Chris@16: {
Chris@16: };
Chris@16: 
Chris@16: template <class R1, class R2>
Chris@16: struct ratio_multiply
Chris@16: : boost::ratio_detail::ratio_multiply<R1, R2>::type
Chris@16: {
Chris@16: };
Chris@16: 
Chris@16: template <class R1, class R2>
Chris@16: struct ratio_divide
Chris@16: : boost::ratio_detail::ratio_divide<R1, R2>::type
Chris@16: {
Chris@16: };
Chris@16: 
Chris@16: //----------------------------------------------------------------------------//
Chris@16: //                                                                            //
Chris@101: //                20.6.3 Comparision of ratio types [ratio.comparison]        //
Chris@16: //                                                                            //
Chris@16: //----------------------------------------------------------------------------//
Chris@16: 
Chris@16: // ratio_equal
Chris@16: 
Chris@16: template <class R1, class R2>
Chris@16: struct ratio_equal
Chris@16:     : public boost::integral_constant<bool,
Chris@16:                                (R1::num == R2::num && R1::den == R2::den)>
Chris@16: {};
Chris@16: 
Chris@16: template <class R1, class R2>
Chris@16: struct ratio_not_equal
Chris@16:     : public boost::integral_constant<bool, !ratio_equal<R1, R2>::value>
Chris@16: {};
Chris@16: 
Chris@16: // ratio_less
Chris@16: 
Chris@16: template <class R1, class R2>
Chris@16: struct ratio_less
Chris@16:     : boost::integral_constant<bool, boost::ratio_detail::ratio_less<R1, R2>::value>
Chris@16: {};
Chris@16: 
Chris@16: template <class R1, class R2>
Chris@16: struct ratio_less_equal
Chris@16:     : boost::integral_constant<bool, !ratio_less<R2, R1>::value>
Chris@16: {};
Chris@16: 
Chris@16: template <class R1, class R2>
Chris@16: struct ratio_greater
Chris@16:     : boost::integral_constant<bool, ratio_less<R2, R1>::value>
Chris@16: {};
Chris@16: 
Chris@16: template <class R1, class R2>
Chris@16: struct ratio_greater_equal
Chris@16:     : boost::integral_constant<bool, !ratio_less<R1, R2>::value>
Chris@16: {};
Chris@16: 
Chris@16: template <class R1, class R2>
Chris@16: struct ratio_gcd :
Chris@16:     ratio<mpl::gcd_c<boost::intmax_t, R1::num, R2::num>::value,
Chris@16:         mpl::lcm_c<boost::intmax_t, R1::den, R2::den>::value>::type
Chris@16: {
Chris@16: };
Chris@16: 
Chris@101:     //----------------------------------------------------------------------------//
Chris@101:     //                                                                            //
Chris@101:     //                More arithmetic on ratio types [ratio.arithmetic]           //
Chris@101:     //                                                                            //
Chris@101:     //----------------------------------------------------------------------------//
Chris@101: 
Chris@16: #ifdef BOOST_RATIO_EXTENSIONS
Chris@16: template <class R>
Chris@16: struct ratio_negate
Chris@16:     : ratio<-R::num, R::den>::type
Chris@16: {
Chris@16: };
Chris@16: template <class R>
Chris@16: struct ratio_abs
Chris@16:     : ratio<mpl::abs_c<boost::intmax_t, R::num>::value, R::den>::type
Chris@16: {
Chris@16: };
Chris@16: template <class R>
Chris@16: struct ratio_sign
Chris@16:     : mpl::sign_c<boost::intmax_t, R::num>
Chris@16: {
Chris@16: };
Chris@101: 
Chris@101: template <class R>
Chris@101: struct ratio_inverse
Chris@101:     : ratio<R::den, R::num>::type
Chris@101: {
Chris@101: };
Chris@101: 
Chris@101: 
Chris@16: template <class R1, class R2>
Chris@16: struct ratio_lcm :
Chris@16:     ratio<mpl::lcm_c<boost::intmax_t, R1::num, R2::num>::value,
Chris@16:         mpl::gcd_c<boost::intmax_t, R1::den, R2::den>::value>::type
Chris@16: {
Chris@16: };
Chris@101: 
Chris@101: template <class R1, class R2>
Chris@101: struct ratio_modulo :
Chris@101:     ratio<(R1::num * R2::den) % (R2::num * R1::den), R1::den * R2::den>::type
Chris@101: {
Chris@101: };
Chris@101: 
Chris@101: namespace detail {
Chris@101:   template <class R1, class R2, bool r1ltr2>
Chris@101:   struct ratio_min : R1 {};
Chris@101:   template <class R1, class R2>
Chris@101:   struct ratio_min<R1,R2,false> : R2 {};
Chris@101: 
Chris@101:   template <class R1, class R2, bool r1ltr2>
Chris@101:   struct ratio_max : R2 {};
Chris@101:   template <class R1, class R2>
Chris@101:   struct ratio_max<R1,R2,false> : R1 {};
Chris@101: }
Chris@101: 
Chris@101: template <class R1, class R2>
Chris@101: struct ratio_min : detail::ratio_min<R1, R2, ratio_less<R1,R2>::value>::type
Chris@101: {
Chris@101: };
Chris@101: 
Chris@101: template <class R1, class R2>
Chris@101: struct ratio_max : detail::ratio_max<R1, R2, ratio_less<R1,R2>::value>::type
Chris@101: {
Chris@101: };
Chris@101: 
Chris@101: template<typename R, int p>
Chris@101: struct ratio_power :
Chris@101:   ratio_multiply<
Chris@101:     typename ratio_power<R, p%2>::type,
Chris@101:     typename ratio_power<typename ratio_multiply<R, R>::type, p/2>::type
Chris@101:   >::type
Chris@101: {};
Chris@101: 
Chris@101: template<typename R>
Chris@101: struct ratio_power<R, 0> : ratio<1>::type {};
Chris@101: 
Chris@101: template<typename R>
Chris@101: struct ratio_power<R, 1> : R {};
Chris@101: 
Chris@101: template<typename R>
Chris@101: struct ratio_power<R, -1> : ratio_divide<ratio<1>, R>::type {};
Chris@101: 
Chris@16: #endif
Chris@16: }  // namespace boost
Chris@16: 
Chris@16: 
Chris@16: #endif  // BOOST_RATIO_RATIO_HPP