// ratio -*- C++ -*-
-// Copyright (C) 2008, 2009, 2010 Free Software Foundation, Inc.
+// Copyright (C) 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the
// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
// <http://www.gnu.org/licenses/>.
-/** @file ratio
+/** @file include/ratio
* This is a Standard C++ Library header.
*/
#ifdef _GLIBCXX_USE_C99_STDINT_TR1
-namespace std
+namespace std _GLIBCXX_VISIBILITY(default)
{
+_GLIBCXX_BEGIN_NAMESPACE_VERSION
+
/**
* @defgroup ratio Rational Arithmetic
* @ingroup utilities
"out of range");
// Note: sign(N) * abs(N) == N
- static const intmax_t num =
+ static constexpr intmax_t num =
_Num * __static_sign<_Den>::value / __static_gcd<_Num, _Den>::value;
- static const intmax_t den =
+ static constexpr intmax_t den =
__static_abs<_Den>::value / __static_gcd<_Num, _Den>::value;
+
+ typedef ratio<num, den> type;
};
template<intmax_t _Num, intmax_t _Den>
- const intmax_t ratio<_Num, _Den>::num;
+ constexpr intmax_t ratio<_Num, _Den>::num;
template<intmax_t _Num, intmax_t _Den>
- const intmax_t ratio<_Num, _Den>::den;
+ constexpr intmax_t ratio<_Num, _Den>::den;
/// ratio_add
template<typename _R1, typename _R2>
struct ratio_add
{
private:
- static const intmax_t __gcd =
+ static constexpr intmax_t __gcd =
__static_gcd<_R1::den, _R2::den>::value;
+ static constexpr intmax_t __n = __safe_add<
+ __safe_multiply<_R1::num, (_R2::den / __gcd)>::value,
+ __safe_multiply<_R2::num, (_R1::den / __gcd)>::value>::value;
+
+ // The new numerator may have common factors with the denominator,
+ // but they have to also be factors of __gcd.
+ static constexpr intmax_t __gcd2 = __static_gcd<__n, __gcd>::value;
public:
- typedef ratio<
- __safe_add<
- __safe_multiply<_R1::num, (_R2::den / __gcd)>::value,
- __safe_multiply<_R2::num, (_R1::den / __gcd)>::value>::value,
- __safe_multiply<_R1::den, (_R2::den / __gcd)>::value> type;
+ typedef ratio<__n / __gcd2,
+ __safe_multiply<_R1::den / __gcd2, _R2::den / __gcd>::value> type;
+
+ static constexpr intmax_t num = type::num;
+ static constexpr intmax_t den = type::den;
};
+ template<typename _R1, typename _R2>
+ constexpr intmax_t ratio_add<_R1, _R2>::num;
+
+ template<typename _R1, typename _R2>
+ constexpr intmax_t ratio_add<_R1, _R2>::den;
+
/// ratio_subtract
template<typename _R1, typename _R2>
struct ratio_subtract
typedef typename ratio_add<
_R1,
ratio<-_R2::num, _R2::den>>::type type;
+
+ static constexpr intmax_t num = type::num;
+ static constexpr intmax_t den = type::den;
};
+ template<typename _R1, typename _R2>
+ constexpr intmax_t ratio_subtract<_R1, _R2>::num;
+
+ template<typename _R1, typename _R2>
+ constexpr intmax_t ratio_subtract<_R1, _R2>::den;
+
/// ratio_multiply
template<typename _R1, typename _R2>
struct ratio_multiply
(_R2::num / __gcd2)>::value,
__safe_multiply<(_R1::den / __gcd2),
(_R2::den / __gcd1)>::value> type;
+
+ static constexpr intmax_t num = type::num;
+ static constexpr intmax_t den = type::den;
};
+ template<typename _R1, typename _R2>
+ constexpr intmax_t ratio_multiply<_R1, _R2>::num;
+
+ template<typename _R1, typename _R2>
+ constexpr intmax_t ratio_multiply<_R1, _R2>::den;
+
/// ratio_divide
template<typename _R1, typename _R2>
struct ratio_divide
typedef typename ratio_multiply<
_R1,
ratio<_R2::den, _R2::num>>::type type;
+
+ static constexpr intmax_t num = type::num;
+ static constexpr intmax_t den = type::den;
};
+ template<typename _R1, typename _R2>
+ constexpr intmax_t ratio_divide<_R1, _R2>::num;
+
+ template<typename _R1, typename _R2>
+ constexpr intmax_t ratio_divide<_R1, _R2>::den;
+
/// ratio_equal
template<typename _R1, typename _R2>
struct ratio_equal
: integral_constant<bool, !ratio_equal<_R1, _R2>::value>
{ };
- template<typename _R1>
+ // 0 <= _Ri < 1
+ // If one is 0, conclude
+ // Otherwise, x < y iff 1/y < 1/x
+ template<typename _R1, typename _R2>
+ struct __ratio_less_impl_2;
+
+ // _Ri > 0
+ // Compare the integral parts, and remove them if they are equal
+ template<typename _R1, typename _R2, intmax_t __q1 = _R1::num / _R1::den,
+ intmax_t __q2 = _R2::num / _R2::den, bool __eq = (__q1 == __q2)>
struct __ratio_less_impl_1
- : integral_constant<bool, _R1::num < _R1::den>
+ : __ratio_less_impl_2<ratio<_R1::num % _R1::den, _R1::den>,
+ ratio<_R2::num % _R2::den, _R2::den> >::type
+ { };
+
+ template<typename _R1, typename _R2, intmax_t __q1, intmax_t __q2>
+ struct __ratio_less_impl_1<_R1, _R2, __q1, __q2, false>
+ : integral_constant<bool, (__q1 < __q2) >
+ { };
+
+ template<typename _R1, typename _R2>
+ struct __ratio_less_impl_2
+ : __ratio_less_impl_1<ratio<_R2::den, _R2::num>,
+ ratio<_R1::den, _R1::num> >::type
+ { };
+
+ template<intmax_t __d1, typename _R2>
+ struct __ratio_less_impl_2<ratio<0, __d1>, _R2>
+ : integral_constant<bool, true>
+ { };
+
+ template<typename _R1, intmax_t __d2>
+ struct __ratio_less_impl_2<_R1, ratio<0, __d2> >
+ : integral_constant<bool, false>
+ { };
+
+ template<intmax_t __d1, intmax_t __d2>
+ struct __ratio_less_impl_2<ratio<0, __d1>, ratio<0, __d2> >
+ : integral_constant<bool, false>
{ };
template<typename _R1, typename _R2,
bool = (__static_sign<_R1::num>::value == -1
&& __static_sign<_R2::num>::value == -1)>
struct __ratio_less_impl
- : __ratio_less_impl_1<typename ratio_divide<_R1, _R2>::type>::type
+ : __ratio_less_impl_1<_R1, _R2>::type
{ };
template<typename _R1, typename _R2>
template<typename _R1, typename _R2>
struct __ratio_less_impl<_R1, _R2, false, true>
- : __ratio_less_impl_1<typename ratio_divide<_R2, _R1>::type>::type
+ : __ratio_less_impl_1<ratio<-_R2::num, _R2::den>,
+ ratio<-_R1::num, _R1::den> >::type
{ };
/// ratio_less
+ // using a continued fraction expansion
template<typename _R1, typename _R2>
struct ratio_less
: __ratio_less_impl<_R1, _R2>::type
typedef ratio< 1000000000000000000, 1> exa;
// @} group ratio
-}
+_GLIBCXX_END_NAMESPACE_VERSION
+} // namespace
#endif //_GLIBCXX_USE_C99_STDINT_TR1
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