diff options
author | uzhas <uzhas@ydb.tech> | 2024-09-15 13:02:38 +0300 |
---|---|---|
committer | uzhas <uzhas@ydb.tech> | 2024-09-15 13:12:54 +0300 |
commit | dbf2aed3f6d5c2cb919f9ace1b876025989f8ab1 (patch) | |
tree | 5708fae74a42e3cfdac955ff0c2488af63d7e80e /contrib | |
parent | 7144046677371d61f38b654e60c561e480cd34e4 (diff) | |
download | ydb-dbf2aed3f6d5c2cb919f9ace1b876025989f8ab1.tar.gz |
add contrib/restricted/boost/rational/include to fix warning
commit_hash:804663433eb5a988140a4afdf332c597ad933686
Diffstat (limited to 'contrib')
-rw-r--r-- | contrib/restricted/boost/rational/include/boost/rational.hpp | 1046 |
1 files changed, 1046 insertions, 0 deletions
diff --git a/contrib/restricted/boost/rational/include/boost/rational.hpp b/contrib/restricted/boost/rational/include/boost/rational.hpp new file mode 100644 index 0000000000..4b66aae7f7 --- /dev/null +++ b/contrib/restricted/boost/rational/include/boost/rational.hpp @@ -0,0 +1,1046 @@ +// Boost rational.hpp header file ------------------------------------------// + +// (C) Copyright Paul Moore 1999. Permission to copy, use, modify, sell and +// distribute this software is granted provided this copyright notice appears +// in all copies. This software is provided "as is" without express or +// implied warranty, and with no claim as to its suitability for any purpose. + +// boostinspect:nolicense (don't complain about the lack of a Boost license) +// (Paul Moore hasn't been in contact for years, so there's no way to change the +// license.) + +// See http://www.boost.org/libs/rational for documentation. + +// Credits: +// Thanks to the boost mailing list in general for useful comments. +// Particular contributions included: +// Andrew D Jewell, for reminding me to take care to avoid overflow +// Ed Brey, for many comments, including picking up on some dreadful typos +// Stephen Silver contributed the test suite and comments on user-defined +// IntType +// Nickolay Mladenov, for the implementation of operator+= + +// Revision History +// 12 Nov 20 Fix operators to work with C++20 rules (Glen Joseph Fernandes) +// 02 Sep 13 Remove unneeded forward declarations; tweak private helper +// function (Daryle Walker) +// 30 Aug 13 Improve exception safety of "assign"; start modernizing I/O code +// (Daryle Walker) +// 27 Aug 13 Add cross-version constructor template, plus some private helper +// functions; add constructor to exception class to take custom +// messages (Daryle Walker) +// 25 Aug 13 Add constexpr qualification wherever possible (Daryle Walker) +// 05 May 12 Reduced use of implicit gcd (Mario Lang) +// 05 Nov 06 Change rational_cast to not depend on division between different +// types (Daryle Walker) +// 04 Nov 06 Off-load GCD and LCM to Boost.Integer; add some invariant checks; +// add std::numeric_limits<> requirement to help GCD (Daryle Walker) +// 31 Oct 06 Recoded both operator< to use round-to-negative-infinity +// divisions; the rational-value version now uses continued fraction +// expansion to avoid overflows, for bug #798357 (Daryle Walker) +// 20 Oct 06 Fix operator bool_type for CW 8.3 (Joaquín M López Muñoz) +// 18 Oct 06 Use EXPLICIT_TEMPLATE_TYPE helper macros from Boost.Config +// (Joaquín M López Muñoz) +// 27 Dec 05 Add Boolean conversion operator (Daryle Walker) +// 28 Sep 02 Use _left versions of operators from operators.hpp +// 05 Jul 01 Recode gcd(), avoiding std::swap (Helmut Zeisel) +// 03 Mar 01 Workarounds for Intel C++ 5.0 (David Abrahams) +// 05 Feb 01 Update operator>> to tighten up input syntax +// 05 Feb 01 Final tidy up of gcd code prior to the new release +// 27 Jan 01 Recode abs() without relying on abs(IntType) +// 21 Jan 01 Include Nickolay Mladenov's operator+= algorithm, +// tidy up a number of areas, use newer features of operators.hpp +// (reduces space overhead to zero), add operator!, +// introduce explicit mixed-mode arithmetic operations +// 12 Jan 01 Include fixes to handle a user-defined IntType better +// 19 Nov 00 Throw on divide by zero in operator /= (John (EBo) David) +// 23 Jun 00 Incorporate changes from Mark Rodgers for Borland C++ +// 22 Jun 00 Change _MSC_VER to BOOST_MSVC so other compilers are not +// affected (Beman Dawes) +// 6 Mar 00 Fix operator-= normalization, #include <string> (Jens Maurer) +// 14 Dec 99 Modifications based on comments from the boost list +// 09 Dec 99 Initial Version (Paul Moore) + +#ifndef BOOST_RATIONAL_HPP +#define BOOST_RATIONAL_HPP + +#include <boost/config.hpp> // for BOOST_NO_STDC_NAMESPACE, BOOST_MSVC, etc +#ifndef BOOST_NO_IOSTREAM +#include <iomanip> // for std::setw +#include <ios> // for std::noskipws, streamsize +#include <istream> // for std::istream +#include <ostream> // for std::ostream +#include <sstream> // for std::ostringstream +#endif +#include <cstddef> // for NULL +#include <stdexcept> // for std::domain_error +#include <string> // for std::string implicit constructor +#include <cstdlib> // for std::abs +#include <boost/call_traits.hpp> // for boost::call_traits +#include <boost/detail/workaround.hpp> // for BOOST_WORKAROUND +#include <boost/assert.hpp> // for BOOST_ASSERT +#include <boost/integer/common_factor_rt.hpp> // for boost::integer::gcd, lcm +#include <limits> // for std::numeric_limits +#include <boost/static_assert.hpp> // for BOOST_STATIC_ASSERT +#include <boost/throw_exception.hpp> +#include <boost/utility/enable_if.hpp> +#include <boost/type_traits/is_convertible.hpp> +#include <boost/type_traits/is_class.hpp> +#include <boost/type_traits/is_same.hpp> +#include <boost/type_traits/is_array.hpp> + +// Control whether depreciated GCD and LCM functions are included (default: yes) +#ifndef BOOST_CONTROL_RATIONAL_HAS_GCD +#define BOOST_CONTROL_RATIONAL_HAS_GCD 1 +#endif + +namespace boost { + +#if BOOST_CONTROL_RATIONAL_HAS_GCD +template <typename IntType> +IntType gcd(IntType n, IntType m) +{ + // Defer to the version in Boost.Integer + return integer::gcd( n, m ); +} + +template <typename IntType> +IntType lcm(IntType n, IntType m) +{ + // Defer to the version in Boost.Integer + return integer::lcm( n, m ); +} +#endif // BOOST_CONTROL_RATIONAL_HAS_GCD + +namespace rational_detail{ + + template <class FromInt, class ToInt, typename Enable = void> + struct is_compatible_integer; + + template <class FromInt, class ToInt> + struct is_compatible_integer<FromInt, ToInt, typename enable_if_c<!is_array<FromInt>::value>::type> + { + BOOST_STATIC_CONSTANT(bool, value = ((std::numeric_limits<FromInt>::is_specialized && std::numeric_limits<FromInt>::is_integer + && (std::numeric_limits<FromInt>::digits <= std::numeric_limits<ToInt>::digits) + && (std::numeric_limits<FromInt>::radix == std::numeric_limits<ToInt>::radix) + && ((std::numeric_limits<FromInt>::is_signed == false) || (std::numeric_limits<ToInt>::is_signed == true)) + && is_convertible<FromInt, ToInt>::value) + || is_same<FromInt, ToInt>::value) + || (is_class<ToInt>::value && is_class<FromInt>::value && is_convertible<FromInt, ToInt>::value)); + }; + + template <class FromInt, class ToInt> + struct is_compatible_integer<FromInt, ToInt, typename enable_if_c<is_array<FromInt>::value>::type> + { + BOOST_STATIC_CONSTANT(bool, value = false); + }; + + template <class FromInt, class ToInt, typename Enable = void> + struct is_backward_compatible_integer; + + template <class FromInt, class ToInt> + struct is_backward_compatible_integer<FromInt, ToInt, typename enable_if_c<!is_array<FromInt>::value>::type> + { + BOOST_STATIC_CONSTANT(bool, value = (std::numeric_limits<FromInt>::is_specialized && std::numeric_limits<FromInt>::is_integer + && !is_compatible_integer<FromInt, ToInt>::value + && (std::numeric_limits<FromInt>::radix == std::numeric_limits<ToInt>::radix) + && is_convertible<FromInt, ToInt>::value)); + }; + + template <class FromInt, class ToInt> + struct is_backward_compatible_integer<FromInt, ToInt, typename enable_if_c<is_array<FromInt>::value>::type> + { + BOOST_STATIC_CONSTANT(bool, value = false); + }; +} + +class bad_rational : public std::domain_error +{ +public: + explicit bad_rational() : std::domain_error("bad rational: zero denominator") {} + explicit bad_rational( char const *what ) : std::domain_error( what ) {} +}; + +template <typename IntType> +class rational +{ + // Class-wide pre-conditions + BOOST_STATIC_ASSERT( ::std::numeric_limits<IntType>::is_specialized ); + + // Helper types + typedef typename boost::call_traits<IntType>::param_type param_type; + + struct helper { IntType parts[2]; }; + typedef IntType (helper::* bool_type)[2]; + +public: + // Component type + typedef IntType int_type; + + BOOST_CONSTEXPR + rational() : num(0), den(1) {} + + template <class T>//, typename enable_if_c<!is_array<T>::value>::type> + BOOST_CONSTEXPR rational(const T& n, typename enable_if_c< + rational_detail::is_compatible_integer<T, IntType>::value + >::type const* = 0) : num(n), den(1) {} + + template <class T, class U> + BOOST_CXX14_CONSTEXPR rational(const T& n, const U& d, typename enable_if_c< + rational_detail::is_compatible_integer<T, IntType>::value && rational_detail::is_compatible_integer<U, IntType>::value + >::type const* = 0) : num(n), den(d) { + normalize(); + } + + template < typename NewType > + BOOST_CONSTEXPR explicit + rational(rational<NewType> const &r, typename enable_if_c<rational_detail::is_compatible_integer<NewType, IntType>::value>::type const* = 0) + : num(r.numerator()), den(is_normalized(int_type(r.numerator()), + int_type(r.denominator())) ? r.denominator() : + (BOOST_THROW_EXCEPTION(bad_rational("bad rational: denormalized conversion")), 0)){} + + template < typename NewType > + BOOST_CONSTEXPR explicit + rational(rational<NewType> const &r, typename disable_if_c<rational_detail::is_compatible_integer<NewType, IntType>::value>::type const* = 0) + : num(r.numerator()), den(is_normalized(int_type(r.numerator()), + int_type(r.denominator())) && is_safe_narrowing_conversion(r.denominator()) && is_safe_narrowing_conversion(r.numerator()) ? r.denominator() : + (BOOST_THROW_EXCEPTION(bad_rational("bad rational: denormalized conversion")), 0)){} + // Default copy constructor and assignment are fine + + // Add assignment from IntType + template <class T> + BOOST_CXX14_CONSTEXPR typename enable_if_c< + rational_detail::is_compatible_integer<T, IntType>::value, rational & + >::type operator=(const T& n) { return assign(static_cast<IntType>(n), static_cast<IntType>(1)); } + + // Assign in place + template <class T, class U> + BOOST_CXX14_CONSTEXPR typename enable_if_c< + rational_detail::is_compatible_integer<T, IntType>::value && rational_detail::is_compatible_integer<U, IntType>::value, rational & + >::type assign(const T& n, const U& d) + { + return *this = rational<IntType>(static_cast<IntType>(n), static_cast<IntType>(d)); + } + // + // The following overloads should probably *not* be provided - + // but are provided for backwards compatibity reasons only. + // These allow for construction/assignment from types that + // are wider than IntType only if there is an implicit + // conversion from T to IntType, they will throw a bad_rational + // if the conversion results in loss of precision or undefined behaviour. + // + template <class T>//, typename enable_if_c<!is_array<T>::value>::type> + BOOST_CXX14_CONSTEXPR rational(const T& n, typename enable_if_c< + rational_detail::is_backward_compatible_integer<T, IntType>::value + >::type const* = 0) + { + assign(n, static_cast<T>(1)); + } + template <class T, class U> + BOOST_CXX14_CONSTEXPR rational(const T& n, const U& d, typename enable_if_c< + (!rational_detail::is_compatible_integer<T, IntType>::value + || !rational_detail::is_compatible_integer<U, IntType>::value) + && std::numeric_limits<T>::is_specialized && std::numeric_limits<T>::is_integer + && (std::numeric_limits<T>::radix == std::numeric_limits<IntType>::radix) + && is_convertible<T, IntType>::value && + std::numeric_limits<U>::is_specialized && std::numeric_limits<U>::is_integer + && (std::numeric_limits<U>::radix == std::numeric_limits<IntType>::radix) + && is_convertible<U, IntType>::value + >::type const* = 0) + { + assign(n, d); + } + template <class T> + BOOST_CXX14_CONSTEXPR typename enable_if_c< + std::numeric_limits<T>::is_specialized && std::numeric_limits<T>::is_integer + && !rational_detail::is_compatible_integer<T, IntType>::value + && (std::numeric_limits<T>::radix == std::numeric_limits<IntType>::radix) + && is_convertible<T, IntType>::value, + rational & + >::type operator=(const T& n) { return assign(n, static_cast<T>(1)); } + + template <class T, class U> + BOOST_CXX14_CONSTEXPR typename enable_if_c< + (!rational_detail::is_compatible_integer<T, IntType>::value + || !rational_detail::is_compatible_integer<U, IntType>::value) + && std::numeric_limits<T>::is_specialized && std::numeric_limits<T>::is_integer + && (std::numeric_limits<T>::radix == std::numeric_limits<IntType>::radix) + && is_convertible<T, IntType>::value && + std::numeric_limits<U>::is_specialized && std::numeric_limits<U>::is_integer + && (std::numeric_limits<U>::radix == std::numeric_limits<IntType>::radix) + && is_convertible<U, IntType>::value, + rational & + >::type assign(const T& n, const U& d) + { + if(!is_safe_narrowing_conversion(n) || !is_safe_narrowing_conversion(d)) + BOOST_THROW_EXCEPTION(bad_rational()); + return *this = rational<IntType>(static_cast<IntType>(n), static_cast<IntType>(d)); + } + + // Access to representation + BOOST_CONSTEXPR + const IntType& numerator() const { return num; } + BOOST_CONSTEXPR + const IntType& denominator() const { return den; } + + // Arithmetic assignment operators + BOOST_CXX14_CONSTEXPR rational& operator+= (const rational& r); + BOOST_CXX14_CONSTEXPR rational& operator-= (const rational& r); + BOOST_CXX14_CONSTEXPR rational& operator*= (const rational& r); + BOOST_CXX14_CONSTEXPR rational& operator/= (const rational& r); + + template <class T> + BOOST_CXX14_CONSTEXPR typename boost::enable_if_c<rational_detail::is_compatible_integer<T, IntType>::value, rational&>::type operator+= (const T& i) + { + num += i * den; + return *this; + } + template <class T> + BOOST_CXX14_CONSTEXPR typename boost::enable_if_c<rational_detail::is_compatible_integer<T, IntType>::value, rational&>::type operator-= (const T& i) + { + num -= i * den; + return *this; + } + template <class T> + BOOST_CXX14_CONSTEXPR typename boost::enable_if_c<rational_detail::is_compatible_integer<T, IntType>::value, rational&>::type operator*= (const T& i) + { + // Avoid overflow and preserve normalization + IntType gcd = integer::gcd(static_cast<IntType>(i), den); + num *= i / gcd; + den /= gcd; + return *this; + } + template <class T> + BOOST_CXX14_CONSTEXPR typename boost::enable_if_c<rational_detail::is_compatible_integer<T, IntType>::value, rational&>::type operator/= (const T& i) + { + // Avoid repeated construction + IntType const zero(0); + + if(i == zero) BOOST_THROW_EXCEPTION(bad_rational()); + if(num == zero) return *this; + + // Avoid overflow and preserve normalization + IntType const gcd = integer::gcd(num, static_cast<IntType>(i)); + num /= gcd; + den *= i / gcd; + + if(den < zero) { + num = -num; + den = -den; + } + + return *this; + } + + // Increment and decrement + BOOST_CXX14_CONSTEXPR const rational& operator++() { num += den; return *this; } + BOOST_CXX14_CONSTEXPR const rational& operator--() { num -= den; return *this; } + + BOOST_CXX14_CONSTEXPR rational operator++(int) + { + rational t(*this); + ++(*this); + return t; + } + BOOST_CXX14_CONSTEXPR rational operator--(int) + { + rational t(*this); + --(*this); + return t; + } + + // Operator not + BOOST_CONSTEXPR + bool operator!() const { return !num; } + + // Boolean conversion + +#if BOOST_WORKAROUND(__MWERKS__,<=0x3003) + // The "ISO C++ Template Parser" option in CW 8.3 chokes on the + // following, hence we selectively disable that option for the + // offending memfun. +#pragma parse_mfunc_templ off +#endif + + BOOST_CONSTEXPR + operator bool_type() const { return operator !() ? 0 : &helper::parts; } + +#if BOOST_WORKAROUND(__MWERKS__,<=0x3003) +#pragma parse_mfunc_templ reset +#endif + + // Comparison operators + BOOST_CXX14_CONSTEXPR bool operator< (const rational& r) const; + BOOST_CXX14_CONSTEXPR bool operator> (const rational& r) const { return r < *this; } + BOOST_CONSTEXPR + bool operator== (const rational& r) const; + + template <class T> + BOOST_CXX14_CONSTEXPR typename boost::enable_if_c<rational_detail::is_compatible_integer<T, IntType>::value, bool>::type operator< (const T& i) const + { + // Avoid repeated construction + int_type const zero(0); + + // Break value into mixed-fraction form, w/ always-nonnegative remainder + BOOST_ASSERT(this->den > zero); + int_type q = this->num / this->den, r = this->num % this->den; + while(r < zero) { r += this->den; --q; } + + // Compare with just the quotient, since the remainder always bumps the + // value up. [Since q = floor(n/d), and if n/d < i then q < i, if n/d == i + // then q == i, if n/d == i + r/d then q == i, and if n/d >= i + 1 then + // q >= i + 1 > i; therefore n/d < i iff q < i.] + return q < i; + } + template <class T> + BOOST_CXX14_CONSTEXPR typename boost::enable_if_c<rational_detail::is_compatible_integer<T, IntType>::value, bool>::type operator>(const T& i) const + { + return operator==(i) ? false : !operator<(i); + } + template <class T> + BOOST_CONSTEXPR typename boost::enable_if_c<rational_detail::is_compatible_integer<T, IntType>::value, bool>::type operator== (const T& i) const + { + return ((den == IntType(1)) && (num == i)); + } + +private: + // Implementation - numerator and denominator (normalized). + // Other possibilities - separate whole-part, or sign, fields? + IntType num; + IntType den; + + // Helper functions + static BOOST_CONSTEXPR + int_type inner_gcd( param_type a, param_type b, int_type const &zero = + int_type(0) ) + { return b == zero ? a : inner_gcd(b, a % b, zero); } + + static BOOST_CONSTEXPR + int_type inner_abs( param_type x, int_type const &zero = int_type(0) ) + { return x < zero ? -x : +x; } + + // Representation note: Fractions are kept in normalized form at all + // times. normalized form is defined as gcd(num,den) == 1 and den > 0. + // In particular, note that the implementation of abs() below relies + // on den always being positive. + BOOST_CXX14_CONSTEXPR bool test_invariant() const; + BOOST_CXX14_CONSTEXPR void normalize(); + + static BOOST_CONSTEXPR + bool is_normalized( param_type n, param_type d, int_type const &zero = + int_type(0), int_type const &one = int_type(1) ) + { + return d > zero && ( n != zero || d == one ) && inner_abs( inner_gcd(n, + d, zero), zero ) == one; + } + // + // Conversion checks: + // + // (1) From an unsigned type with more digits than IntType: + // + template <class T> + BOOST_CONSTEXPR static typename boost::enable_if_c<(std::numeric_limits<T>::digits > std::numeric_limits<IntType>::digits) && (std::numeric_limits<T>::is_signed == false), bool>::type is_safe_narrowing_conversion(const T& val) + { + return val < (T(1) << std::numeric_limits<IntType>::digits); + } + // + // (2) From a signed type with more digits than IntType, and IntType also signed: + // + template <class T> + BOOST_CONSTEXPR static typename boost::enable_if_c<(std::numeric_limits<T>::digits > std::numeric_limits<IntType>::digits) && (std::numeric_limits<T>::is_signed == true) && (std::numeric_limits<IntType>::is_signed == true), bool>::type is_safe_narrowing_conversion(const T& val) + { + // Note that this check assumes IntType has a 2's complement representation, + // we don't want to try to convert a std::numeric_limits<IntType>::min() to + // a T because that conversion may not be allowed (this happens when IntType + // is from Boost.Multiprecision). + return (val < (T(1) << std::numeric_limits<IntType>::digits)) && (val >= -(T(1) << std::numeric_limits<IntType>::digits)); + } + // + // (3) From a signed type with more digits than IntType, and IntType unsigned: + // + template <class T> + BOOST_CONSTEXPR static typename boost::enable_if_c<(std::numeric_limits<T>::digits > std::numeric_limits<IntType>::digits) && (std::numeric_limits<T>::is_signed == true) && (std::numeric_limits<IntType>::is_signed == false), bool>::type is_safe_narrowing_conversion(const T& val) + { + return (val < (T(1) << std::numeric_limits<IntType>::digits)) && (val >= 0); + } + // + // (4) From a signed type with fewer digits than IntType, and IntType unsigned: + // + template <class T> + BOOST_CONSTEXPR static typename boost::enable_if_c<(std::numeric_limits<T>::digits <= std::numeric_limits<IntType>::digits) && (std::numeric_limits<T>::is_signed == true) && (std::numeric_limits<IntType>::is_signed == false), bool>::type is_safe_narrowing_conversion(const T& val) + { + return val >= 0; + } + // + // (5) From an unsigned type with fewer digits than IntType, and IntType signed: + // + template <class T> + BOOST_CONSTEXPR static typename boost::enable_if_c<(std::numeric_limits<T>::digits <= std::numeric_limits<IntType>::digits) && (std::numeric_limits<T>::is_signed == false) && (std::numeric_limits<IntType>::is_signed == true), bool>::type is_safe_narrowing_conversion(const T&) + { + return true; + } + // + // (6) From an unsigned type with fewer digits than IntType, and IntType unsigned: + // + template <class T> + BOOST_CONSTEXPR static typename boost::enable_if_c<(std::numeric_limits<T>::digits <= std::numeric_limits<IntType>::digits) && (std::numeric_limits<T>::is_signed == false) && (std::numeric_limits<IntType>::is_signed == false), bool>::type is_safe_narrowing_conversion(const T&) + { + return true; + } + // + // (7) From an signed type with fewer digits than IntType, and IntType signed: + // + template <class T> + BOOST_CONSTEXPR static typename boost::enable_if_c<(std::numeric_limits<T>::digits <= std::numeric_limits<IntType>::digits) && (std::numeric_limits<T>::is_signed == true) && (std::numeric_limits<IntType>::is_signed == true), bool>::type is_safe_narrowing_conversion(const T&) + { + return true; + } +}; + +// Unary plus and minus +template <typename IntType> +BOOST_CONSTEXPR +inline rational<IntType> operator+ (const rational<IntType>& r) +{ + return r; +} + +template <typename IntType> +BOOST_CXX14_CONSTEXPR +inline rational<IntType> operator- (const rational<IntType>& r) +{ + return rational<IntType>(static_cast<IntType>(-r.numerator()), r.denominator()); +} + +// Arithmetic assignment operators +template <typename IntType> +BOOST_CXX14_CONSTEXPR rational<IntType>& rational<IntType>::operator+= (const rational<IntType>& r) +{ + // This calculation avoids overflow, and minimises the number of expensive + // calculations. Thanks to Nickolay Mladenov for this algorithm. + // + // Proof: + // We have to compute a/b + c/d, where gcd(a,b)=1 and gcd(b,c)=1. + // Let g = gcd(b,d), and b = b1*g, d=d1*g. Then gcd(b1,d1)=1 + // + // The result is (a*d1 + c*b1) / (b1*d1*g). + // Now we have to normalize this ratio. + // Let's assume h | gcd((a*d1 + c*b1), (b1*d1*g)), and h > 1 + // If h | b1 then gcd(h,d1)=1 and hence h|(a*d1+c*b1) => h|a. + // But since gcd(a,b1)=1 we have h=1. + // Similarly h|d1 leads to h=1. + // So we have that h | gcd((a*d1 + c*b1) , (b1*d1*g)) => h|g + // Finally we have gcd((a*d1 + c*b1), (b1*d1*g)) = gcd((a*d1 + c*b1), g) + // Which proves that instead of normalizing the result, it is better to + // divide num and den by gcd((a*d1 + c*b1), g) + + // Protect against self-modification + IntType r_num = r.num; + IntType r_den = r.den; + + IntType g = integer::gcd(den, r_den); + den /= g; // = b1 from the calculations above + num = num * (r_den / g) + r_num * den; + g = integer::gcd(num, g); + num /= g; + den *= r_den/g; + + return *this; +} + +template <typename IntType> +BOOST_CXX14_CONSTEXPR rational<IntType>& rational<IntType>::operator-= (const rational<IntType>& r) +{ + // Protect against self-modification + IntType r_num = r.num; + IntType r_den = r.den; + + // This calculation avoids overflow, and minimises the number of expensive + // calculations. It corresponds exactly to the += case above + IntType g = integer::gcd(den, r_den); + den /= g; + num = num * (r_den / g) - r_num * den; + g = integer::gcd(num, g); + num /= g; + den *= r_den/g; + + return *this; +} + +template <typename IntType> +BOOST_CXX14_CONSTEXPR rational<IntType>& rational<IntType>::operator*= (const rational<IntType>& r) +{ + // Protect against self-modification + IntType r_num = r.num; + IntType r_den = r.den; + + // Avoid overflow and preserve normalization + IntType gcd1 = integer::gcd(num, r_den); + IntType gcd2 = integer::gcd(r_num, den); + num = (num/gcd1) * (r_num/gcd2); + den = (den/gcd2) * (r_den/gcd1); + return *this; +} + +template <typename IntType> +BOOST_CXX14_CONSTEXPR rational<IntType>& rational<IntType>::operator/= (const rational<IntType>& r) +{ + // Protect against self-modification + IntType r_num = r.num; + IntType r_den = r.den; + + // Avoid repeated construction + IntType zero(0); + + // Trap division by zero + if (r_num == zero) + BOOST_THROW_EXCEPTION(bad_rational()); + if (num == zero) + return *this; + + // Avoid overflow and preserve normalization + IntType gcd1 = integer::gcd(num, r_num); + IntType gcd2 = integer::gcd(r_den, den); + num = (num/gcd1) * (r_den/gcd2); + den = (den/gcd2) * (r_num/gcd1); + + if (den < zero) { + num = -num; + den = -den; + } + return *this; +} + + +// +// Non-member operators: previously these were provided by Boost.Operator, but these had a number of +// drawbacks, most notably, that in order to allow inter-operability with IntType code such as this: +// +// rational<int> r(3); +// assert(r == 3.5); // compiles and passes!! +// +// Happens to be allowed as well :-( +// +// There are three possible cases for each operator: +// 1) rational op rational. +// 2) rational op integer +// 3) integer op rational +// Cases (1) and (2) are folded into the one function. +// +template <class IntType, class Arg> +BOOST_CXX14_CONSTEXPR +inline typename boost::enable_if_c < + rational_detail::is_compatible_integer<Arg, IntType>::value || is_same<rational<IntType>, Arg>::value, rational<IntType> >::type + operator + (const rational<IntType>& a, const Arg& b) +{ + rational<IntType> t(a); + return t += b; +} +template <class Arg, class IntType> +BOOST_CXX14_CONSTEXPR +inline typename boost::enable_if_c < + rational_detail::is_compatible_integer<Arg, IntType>::value, rational<IntType> >::type + operator + (const Arg& b, const rational<IntType>& a) +{ + rational<IntType> t(a); + return t += b; +} + +template <class IntType, class Arg> +BOOST_CXX14_CONSTEXPR +inline typename boost::enable_if_c < + rational_detail::is_compatible_integer<Arg, IntType>::value || is_same<rational<IntType>, Arg>::value, rational<IntType> >::type + operator - (const rational<IntType>& a, const Arg& b) +{ + rational<IntType> t(a); + return t -= b; +} +template <class Arg, class IntType> +BOOST_CXX14_CONSTEXPR +inline typename boost::enable_if_c < + rational_detail::is_compatible_integer<Arg, IntType>::value, rational<IntType> >::type + operator - (const Arg& b, const rational<IntType>& a) +{ + rational<IntType> t(a); + return -(t -= b); +} + +template <class IntType, class Arg> +BOOST_CXX14_CONSTEXPR +inline typename boost::enable_if_c < + rational_detail::is_compatible_integer<Arg, IntType>::value || is_same<rational<IntType>, Arg>::value, rational<IntType> >::type + operator * (const rational<IntType>& a, const Arg& b) +{ + rational<IntType> t(a); + return t *= b; +} +template <class Arg, class IntType> +BOOST_CXX14_CONSTEXPR +inline typename boost::enable_if_c < + rational_detail::is_compatible_integer<Arg, IntType>::value, rational<IntType> >::type + operator * (const Arg& b, const rational<IntType>& a) +{ + rational<IntType> t(a); + return t *= b; +} + +template <class IntType, class Arg> +BOOST_CXX14_CONSTEXPR +inline typename boost::enable_if_c < + rational_detail::is_compatible_integer<Arg, IntType>::value || is_same<rational<IntType>, Arg>::value, rational<IntType> >::type + operator / (const rational<IntType>& a, const Arg& b) +{ + rational<IntType> t(a); + return t /= b; +} +template <class Arg, class IntType> +BOOST_CXX14_CONSTEXPR +inline typename boost::enable_if_c < + rational_detail::is_compatible_integer<Arg, IntType>::value, rational<IntType> >::type + operator / (const Arg& b, const rational<IntType>& a) +{ + rational<IntType> t(b); + return t /= a; +} + +template <class IntType, class Arg> +BOOST_CXX14_CONSTEXPR +inline typename boost::enable_if_c < + rational_detail::is_compatible_integer<Arg, IntType>::value || is_same<rational<IntType>, Arg>::value, bool>::type + operator <= (const rational<IntType>& a, const Arg& b) +{ + return !a.operator>(b); +} +template <class Arg, class IntType> +BOOST_CXX14_CONSTEXPR +inline typename boost::enable_if_c < + rational_detail::is_compatible_integer<Arg, IntType>::value, bool>::type + operator <= (const Arg& b, const rational<IntType>& a) +{ + return a >= b; +} + +template <class IntType, class Arg> +BOOST_CXX14_CONSTEXPR +inline typename boost::enable_if_c < + rational_detail::is_compatible_integer<Arg, IntType>::value || is_same<rational<IntType>, Arg>::value, bool>::type + operator >= (const rational<IntType>& a, const Arg& b) +{ + return !a.operator<(b); +} +template <class Arg, class IntType> +BOOST_CXX14_CONSTEXPR +inline typename boost::enable_if_c < + rational_detail::is_compatible_integer<Arg, IntType>::value, bool>::type + operator >= (const Arg& b, const rational<IntType>& a) +{ + return a <= b; +} + +template <class IntType, class Arg> +BOOST_CONSTEXPR +inline typename boost::enable_if_c < + rational_detail::is_compatible_integer<Arg, IntType>::value || is_same<rational<IntType>, Arg>::value, bool>::type + operator != (const rational<IntType>& a, const Arg& b) +{ + return !a.operator==(b); +} +template <class Arg, class IntType> +BOOST_CONSTEXPR +inline typename boost::enable_if_c < + rational_detail::is_compatible_integer<Arg, IntType>::value, bool>::type + operator != (const Arg& b, const rational<IntType>& a) +{ + return !(b == a); +} + +template <class Arg, class IntType> +BOOST_CXX14_CONSTEXPR +inline typename boost::enable_if_c < + rational_detail::is_compatible_integer<Arg, IntType>::value, bool>::type + operator < (const Arg& b, const rational<IntType>& a) +{ + return a.operator>(b); +} +template <class Arg, class IntType> +BOOST_CXX14_CONSTEXPR +inline typename boost::enable_if_c < + rational_detail::is_compatible_integer<Arg, IntType>::value, bool>::type + operator > (const Arg& b, const rational<IntType>& a) +{ + return a.operator<(b); +} +template <class Arg, class IntType> +BOOST_CONSTEXPR +inline typename boost::enable_if_c < + rational_detail::is_compatible_integer<Arg, IntType>::value, bool>::type + operator == (const Arg& b, const rational<IntType>& a) +{ + return a.operator==(b); +} + +// Comparison operators +template <typename IntType> +BOOST_CXX14_CONSTEXPR +bool rational<IntType>::operator< (const rational<IntType>& r) const +{ + // Avoid repeated construction + int_type const zero( 0 ); + + // This should really be a class-wide invariant. The reason for these + // checks is that for 2's complement systems, INT_MIN has no corresponding + // positive, so negating it during normalization keeps it INT_MIN, which + // is bad for later calculations that assume a positive denominator. + BOOST_ASSERT( this->den > zero ); + BOOST_ASSERT( r.den > zero ); + + // Determine relative order by expanding each value to its simple continued + // fraction representation using the Euclidian GCD algorithm. + struct { int_type n, d, q, r; } + ts = { this->num, this->den, static_cast<int_type>(this->num / this->den), + static_cast<int_type>(this->num % this->den) }, + rs = { r.num, r.den, static_cast<int_type>(r.num / r.den), + static_cast<int_type>(r.num % r.den) }; + unsigned reverse = 0u; + + // Normalize negative moduli by repeatedly adding the (positive) denominator + // and decrementing the quotient. Later cycles should have all positive + // values, so this only has to be done for the first cycle. (The rules of + // C++ require a nonnegative quotient & remainder for a nonnegative dividend + // & positive divisor.) + while ( ts.r < zero ) { ts.r += ts.d; --ts.q; } + while ( rs.r < zero ) { rs.r += rs.d; --rs.q; } + + // Loop through and compare each variable's continued-fraction components + for ( ;; ) + { + // The quotients of the current cycle are the continued-fraction + // components. Comparing two c.f. is comparing their sequences, + // stopping at the first difference. + if ( ts.q != rs.q ) + { + // Since reciprocation changes the relative order of two variables, + // and c.f. use reciprocals, the less/greater-than test reverses + // after each index. (Start w/ non-reversed @ whole-number place.) + return reverse ? ts.q > rs.q : ts.q < rs.q; + } + + // Prepare the next cycle + reverse ^= 1u; + + if ( (ts.r == zero) || (rs.r == zero) ) + { + // At least one variable's c.f. expansion has ended + break; + } + + ts.n = ts.d; ts.d = ts.r; + ts.q = ts.n / ts.d; ts.r = ts.n % ts.d; + rs.n = rs.d; rs.d = rs.r; + rs.q = rs.n / rs.d; rs.r = rs.n % rs.d; + } + + // Compare infinity-valued components for otherwise equal sequences + if ( ts.r == rs.r ) + { + // Both remainders are zero, so the next (and subsequent) c.f. + // components for both sequences are infinity. Therefore, the sequences + // and their corresponding values are equal. + return false; + } + else + { +#ifdef BOOST_MSVC +#pragma warning(push) +#pragma warning(disable:4800) +#endif + // Exactly one of the remainders is zero, so all following c.f. + // components of that variable are infinity, while the other variable + // has a finite next c.f. component. So that other variable has the + // lesser value (modulo the reversal flag!). + return ( ts.r != zero ) != static_cast<bool>( reverse ); +#ifdef BOOST_MSVC +#pragma warning(pop) +#endif + } +} + +template <typename IntType> +BOOST_CONSTEXPR +inline bool rational<IntType>::operator== (const rational<IntType>& r) const +{ + return ((num == r.num) && (den == r.den)); +} + +// Invariant check +template <typename IntType> +BOOST_CXX14_CONSTEXPR +inline bool rational<IntType>::test_invariant() const +{ + return ( this->den > int_type(0) ) && ( integer::gcd(this->num, this->den) == + int_type(1) ); +} + +// Normalisation +template <typename IntType> +BOOST_CXX14_CONSTEXPR void rational<IntType>::normalize() +{ + // Avoid repeated construction + IntType zero(0); + + if (den == zero) + BOOST_THROW_EXCEPTION(bad_rational()); + + // Handle the case of zero separately, to avoid division by zero + if (num == zero) { + den = IntType(1); + return; + } + + IntType g = integer::gcd(num, den); + + num /= g; + den /= g; + + if (den < -(std::numeric_limits<IntType>::max)()) { + BOOST_THROW_EXCEPTION(bad_rational("bad rational: non-zero singular denominator")); + } + + // Ensure that the denominator is positive + if (den < zero) { + num = -num; + den = -den; + } + + BOOST_ASSERT( this->test_invariant() ); +} + +#ifndef BOOST_NO_IOSTREAM +namespace detail { + + // A utility class to reset the format flags for an istream at end + // of scope, even in case of exceptions + struct resetter { + resetter(std::istream& is) : is_(is), f_(is.flags()) {} + ~resetter() { is_.flags(f_); } + std::istream& is_; + std::istream::fmtflags f_; // old GNU c++ lib has no ios_base + }; + +} + +// Input and output +template <typename IntType> +std::istream& operator>> (std::istream& is, rational<IntType>& r) +{ + using std::ios; + + IntType n = IntType(0), d = IntType(1); + char c = 0; + detail::resetter sentry(is); + + if ( is >> n ) + { + if ( is.get(c) ) + { + if ( c == '/' ) + { + if ( is >> std::noskipws >> d ) + try { + r.assign( n, d ); + } catch ( bad_rational & ) { // normalization fail + try { is.setstate(ios::failbit); } + catch ( ... ) {} // don't throw ios_base::failure... + if ( is.exceptions() & ios::failbit ) + throw; // ...but the original exception instead + // ELSE: suppress the exception, use just error flags + } + } + else + is.setstate( ios::failbit ); + } + } + + return is; +} + +// Add manipulators for output format? +template <typename IntType> +std::ostream& operator<< (std::ostream& os, const rational<IntType>& r) +{ + // The slash directly precedes the denominator, which has no prefixes. + std::ostringstream ss; + + ss.copyfmt( os ); + ss.tie( NULL ); + ss.exceptions( std::ios::goodbit ); + ss.width( 0 ); + ss << std::noshowpos << std::noshowbase << '/' << r.denominator(); + + // The numerator holds the showpos, internal, and showbase flags. + std::string const tail = ss.str(); + std::streamsize const w = + os.width() - static_cast<std::streamsize>( tail.size() ); + + ss.clear(); + ss.str( "" ); + ss.flags( os.flags() ); + ss << std::setw( w < 0 || (os.flags() & std::ios::adjustfield) != + std::ios::internal ? 0 : w ) << r.numerator(); + return os << ss.str() + tail; +} +#endif // BOOST_NO_IOSTREAM + +// Type conversion +template <typename T, typename IntType> +BOOST_CONSTEXPR +inline T rational_cast(const rational<IntType>& src) +{ + return static_cast<T>(src.numerator())/static_cast<T>(src.denominator()); +} + +// Do not use any abs() defined on IntType - it isn't worth it, given the +// difficulties involved (Koenig lookup required, there may not *be* an abs() +// defined, etc etc). +template <typename IntType> +BOOST_CXX14_CONSTEXPR +inline rational<IntType> abs(const rational<IntType>& r) +{ + return r.numerator() >= IntType(0)? r: -r; +} + +namespace integer { + +template <typename IntType> +struct gcd_evaluator< rational<IntType> > +{ + typedef rational<IntType> result_type, + first_argument_type, second_argument_type; + result_type operator() ( first_argument_type const &a + , second_argument_type const &b + ) const + { + return result_type(integer::gcd(a.numerator(), b.numerator()), + integer::lcm(a.denominator(), b.denominator())); + } +}; + +template <typename IntType> +struct lcm_evaluator< rational<IntType> > +{ + typedef rational<IntType> result_type, + first_argument_type, second_argument_type; + result_type operator() ( first_argument_type const &a + , second_argument_type const &b + ) const + { + return result_type(integer::lcm(a.numerator(), b.numerator()), + integer::gcd(a.denominator(), b.denominator())); + } +}; + +} // namespace integer + +} // namespace boost + +#endif // BOOST_RATIONAL_HPP |