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Diffstat (limited to '8/sources/cxx-stl/gnu-libstdc++/4.4.3/include/ratio')
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diff --git a/8/sources/cxx-stl/gnu-libstdc++/4.4.3/include/ratio b/8/sources/cxx-stl/gnu-libstdc++/4.4.3/include/ratio new file mode 100644 index 0000000..f0e8831 --- /dev/null +++ b/8/sources/cxx-stl/gnu-libstdc++/4.4.3/include/ratio @@ -0,0 +1,303 @@ +// ratio -*- C++ -*- + +// Copyright (C) 2008, 2009 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 +// terms of the GNU General Public License as published by the +// Free Software Foundation; either version 3, or (at your option) +// any later version. + +// This library is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU General Public License for more details. + +// Under Section 7 of GPL version 3, you are granted additional +// permissions described in the GCC Runtime Library Exception, version +// 3.1, as published by the Free Software Foundation. + +// You should have received a copy of the GNU General Public License and +// a copy of the GCC Runtime Library Exception along with this program; +// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see +// <http://www.gnu.org/licenses/>. + +/** @file ratio + * This is a Standard C++ Library header. + */ + +#ifndef _GLIBCXX_RATIO +#define _GLIBCXX_RATIO 1 + +#pragma GCC system_header + +#ifndef __GXX_EXPERIMENTAL_CXX0X__ +# include <c++0x_warning.h> +#else + +#include <type_traits> +#include <cstdint> + +#ifdef _GLIBCXX_USE_C99_STDINT_TR1 + +namespace std +{ + /** + * @defgroup ratio Rational Arithmetic + * @ingroup utilities + * + * Compile time representation of fininte rational numbers. + * @{ + */ + + template<intmax_t _Pn> + struct __static_sign + : integral_constant<intmax_t, (_Pn < 0) ? -1 : 1> + { }; + + template<intmax_t _Pn> + struct __static_abs + : integral_constant<intmax_t, _Pn * __static_sign<_Pn>::value> + { }; + + template<intmax_t _Pn, intmax_t _Qn> + struct __static_gcd; + + template<intmax_t _Pn, intmax_t _Qn> + struct __static_gcd + : __static_gcd<_Qn, (_Pn % _Qn)> + { }; + + template<intmax_t _Pn> + struct __static_gcd<_Pn, 0> + : integral_constant<intmax_t, __static_abs<_Pn>::value> + { }; + + template<intmax_t _Qn> + struct __static_gcd<0, _Qn> + : integral_constant<intmax_t, __static_abs<_Qn>::value> + { }; + + // Let c = 2^(half # of bits in an intmax_t) + // then we find a1, a0, b1, b0 s.t. N = a1*c + a0, M = b1*c + b0 + // The multiplication of N and M becomes, + // N * M = (a1 * b1)c^2 + (a0 * b1 + b0 * a1)c + a0 * b0 + // Multiplication is safe if each term and the sum of the terms + // is representable by intmax_t. + template<intmax_t _Pn, intmax_t _Qn> + struct __safe_multiply + { + private: + static const uintmax_t __c = uintmax_t(1) << (sizeof(intmax_t) * 4); + + static const uintmax_t __a0 = __static_abs<_Pn>::value % __c; + static const uintmax_t __a1 = __static_abs<_Pn>::value / __c; + static const uintmax_t __b0 = __static_abs<_Qn>::value % __c; + static const uintmax_t __b1 = __static_abs<_Qn>::value / __c; + + static_assert(__a1 == 0 || __b1 == 0, + "overflow in multiplication"); + static_assert(__a0 * __b1 + __b0 * __a1 < (__c >> 1), + "overflow in multiplication"); + static_assert(__b0 * __a0 <= __INTMAX_MAX__, + "overflow in multiplication"); + static_assert((__a0 * __b1 + __b0 * __a1) * __c <= + __INTMAX_MAX__ - __b0 * __a0, "overflow in multiplication"); + + public: + static const intmax_t value = _Pn * _Qn; + }; + + // Helpers for __safe_add + template<intmax_t _Pn, intmax_t _Qn, bool> + struct __add_overflow_check_impl + : integral_constant<bool, (_Pn <= __INTMAX_MAX__ - _Qn)> + { }; + + template<intmax_t _Pn, intmax_t _Qn> + struct __add_overflow_check_impl<_Pn, _Qn, false> + : integral_constant<bool, (_Pn >= -__INTMAX_MAX__ - _Qn)> + { }; + + template<intmax_t _Pn, intmax_t _Qn> + struct __add_overflow_check + : __add_overflow_check_impl<_Pn, _Qn, (_Qn >= 0)> + { }; + + template<intmax_t _Pn, intmax_t _Qn> + struct __safe_add + { + static_assert(__add_overflow_check<_Pn, _Qn>::value != 0, + "overflow in addition"); + + static const intmax_t value = _Pn + _Qn; + }; + + /** + * @brief Provides compile-time rational arithmetic. + * + * This class template represents any finite rational number with a + * numerator and denominator representable by compile-time constants of + * type intmax_t. The ratio is simplified when instantiated. + * + * For example: + * @code + * std::ratio<7,-21>::num == -1; + * std::ratio<7,-21>::den == 3; + * @endcode + * + */ + template<intmax_t _Num, intmax_t _Den = 1> + struct ratio + { + static_assert(_Den != 0, "denominator cannot be zero"); + static_assert(_Num >= -__INTMAX_MAX__ && _Den >= -__INTMAX_MAX__, + "out of range"); + + // Note: sign(N) * abs(N) == N + static const intmax_t num = + _Num * __static_sign<_Den>::value / __static_gcd<_Num, _Den>::value; + + static const intmax_t den = + __static_abs<_Den>::value / __static_gcd<_Num, _Den>::value; + }; + + template<intmax_t _Num, intmax_t _Den> + const intmax_t ratio<_Num, _Den>::num; + + template<intmax_t _Num, intmax_t _Den> + const intmax_t ratio<_Num, _Den>::den; + + /// ratio_add + template<typename _R1, typename _R2> + struct ratio_add + { + private: + static const intmax_t __gcd = + __static_gcd<_R1::den, _R2::den>::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; + }; + + /// ratio_subtract + template<typename _R1, typename _R2> + struct ratio_subtract + { + typedef typename ratio_add< + _R1, + ratio<-_R2::num, _R2::den>>::type type; + }; + + /// ratio_multiply + template<typename _R1, typename _R2> + struct ratio_multiply + { + private: + static const intmax_t __gcd1 = + __static_gcd<_R1::num, _R2::den>::value; + static const intmax_t __gcd2 = + __static_gcd<_R2::num, _R1::den>::value; + + public: + typedef ratio< + __safe_multiply<(_R1::num / __gcd1), + (_R2::num / __gcd2)>::value, + __safe_multiply<(_R1::den / __gcd2), + (_R2::den / __gcd1)>::value> type; + }; + + /// ratio_divide + template<typename _R1, typename _R2> + struct ratio_divide + { + static_assert(_R2::num != 0, "division by 0"); + + typedef typename ratio_multiply< + _R1, + ratio<_R2::den, _R2::num>>::type type; + }; + + /// ratio_equal + template<typename _R1, typename _R2> + struct ratio_equal + : integral_constant<bool, _R1::num == _R2::num && _R1::den == _R2::den> + { }; + + /// ratio_not_equal + template<typename _R1, typename _R2> + struct ratio_not_equal + : integral_constant<bool, !ratio_equal<_R1, _R2>::value> + { }; + + template<typename _R1, typename _R2> + struct __ratio_less_simple_impl + : integral_constant<bool, + (__safe_multiply<_R1::num, _R2::den>::value + < __safe_multiply<_R2::num, _R1::den>::value)> + { }; + + // If the denominators are equal or the signs differ, we can just compare + // numerators, otherwise fallback to the simple cross-multiply method. + template<typename _R1, typename _R2> + struct __ratio_less_impl + : conditional<(_R1::den == _R2::den + || (__static_sign<_R1::num>::value + != __static_sign<_R2::num>::value)), + integral_constant<bool, (_R1::num < _R2::num)>, + __ratio_less_simple_impl<_R1, _R2>>::type + { }; + + /// ratio_less + template<typename _R1, typename _R2> + struct ratio_less + : __ratio_less_impl<_R1, _R2>::type + { }; + + /// ratio_less_equal + template<typename _R1, typename _R2> + struct ratio_less_equal + : integral_constant<bool, !ratio_less<_R2, _R1>::value> + { }; + + /// ratio_greater + template<typename _R1, typename _R2> + struct ratio_greater + : integral_constant<bool, ratio_less<_R2, _R1>::value> + { }; + + /// ratio_greater_equal + template<typename _R1, typename _R2> + struct ratio_greater_equal + : integral_constant<bool, !ratio_less<_R1, _R2>::value> + { }; + + typedef ratio<1, 1000000000000000000> atto; + typedef ratio<1, 1000000000000000> femto; + typedef ratio<1, 1000000000000> pico; + typedef ratio<1, 1000000000> nano; + typedef ratio<1, 1000000> micro; + typedef ratio<1, 1000> milli; + typedef ratio<1, 100> centi; + typedef ratio<1, 10> deci; + typedef ratio< 10, 1> deca; + typedef ratio< 100, 1> hecto; + typedef ratio< 1000, 1> kilo; + typedef ratio< 1000000, 1> mega; + typedef ratio< 1000000000, 1> giga; + typedef ratio< 1000000000000, 1> tera; + typedef ratio< 1000000000000000, 1> peta; + typedef ratio< 1000000000000000000, 1> exa; + + // @} group ratio +} + +#endif //_GLIBCXX_USE_C99_STDINT_TR1 + +#endif //__GXX_EXPERIMENTAL_CXX0X__ + +#endif //_GLIBCXX_RATIO |