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// Definition of numeric_limits replacement traits P1841R1 -*- C++ -*- |
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|
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// Copyright (C) 2020-2021 Free Software Foundation, Inc. |
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// |
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// This file is part of the GNU ISO C++ Library. This library is free |
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// software; you can redistribute it and/or modify it under the |
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// terms of the GNU General Public License as published by the |
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// Free Software Foundation; either version 3, or (at your option) |
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// any later version. |
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|
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// This library is distributed in the hope that it will be useful, |
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// but WITHOUT ANY WARRANTY; without even the implied warranty of |
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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// GNU General Public License for more details. |
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|
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// Under Section 7 of GPL version 3, you are granted additional |
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// permissions described in the GCC Runtime Library Exception, version |
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// 3.1, as published by the Free Software Foundation. |
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|
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// You should have received a copy of the GNU General Public License and |
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// a copy of the GCC Runtime Library Exception along with this program; |
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// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see |
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// <http://www.gnu.org/licenses/>. |
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|
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#include <type_traits> |
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|
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namespace std { |
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|
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template <template <typename> class _Trait, typename _Tp, typename = void> |
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struct __value_exists_impl : false_type {}; |
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|
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template <template <typename> class _Trait, typename _Tp> |
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struct __value_exists_impl<_Trait, _Tp, void_t<decltype(_Trait<_Tp>::value)>> |
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: true_type {}; |
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|
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template <typename _Tp, bool = is_arithmetic_v<_Tp>> |
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struct __digits_impl {}; |
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|
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template <typename _Tp> |
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struct __digits_impl<_Tp, true> |
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{ |
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static inline constexpr int value |
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= sizeof(_Tp) * __CHAR_BIT__ - is_signed_v<_Tp>; |
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}; |
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|
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template <> |
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struct __digits_impl<float, true> |
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{ static inline constexpr int value = __FLT_MANT_DIG__; }; |
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|
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template <> |
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struct __digits_impl<double, true> |
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{ static inline constexpr int value = __DBL_MANT_DIG__; }; |
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|
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template <> |
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struct __digits_impl<long double, true> |
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{ static inline constexpr int value = __LDBL_MANT_DIG__; }; |
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|
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template <typename _Tp, bool = is_arithmetic_v<_Tp>> |
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struct __digits10_impl {}; |
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|
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template <typename _Tp> |
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struct __digits10_impl<_Tp, true> |
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{ |
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// The fraction 643/2136 approximates log10(2) to 7 significant digits. |
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static inline constexpr int value = __digits_impl<_Tp>::value * 643L / 2136; |
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}; |
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|
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template <> |
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struct __digits10_impl<float, true> |
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{ static inline constexpr int value = __FLT_DIG__; }; |
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|
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template <> |
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struct __digits10_impl<double, true> |
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{ static inline constexpr int value = __DBL_DIG__; }; |
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|
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template <> |
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struct __digits10_impl<long double, true> |
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{ static inline constexpr int value = __LDBL_DIG__; }; |
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|
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template <typename _Tp, bool = is_arithmetic_v<_Tp>> |
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struct __max_digits10_impl {}; |
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|
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template <typename _Tp> |
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struct __max_digits10_impl<_Tp, true> |
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{ |
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static inline constexpr int value |
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= is_floating_point_v<_Tp> ? 2 + __digits_impl<_Tp>::value * 643L / 2136 |
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: __digits10_impl<_Tp>::value + 1; |
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}; |
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|
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template <typename _Tp> |
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struct __max_exponent_impl {}; |
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|
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template <> |
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struct __max_exponent_impl<float> |
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{ static inline constexpr int value = __FLT_MAX_EXP__; }; |
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|
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template <> |
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struct __max_exponent_impl<double> |
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{ static inline constexpr int value = __DBL_MAX_EXP__; }; |
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|
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template <> |
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struct __max_exponent_impl<long double> |
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{ static inline constexpr int value = __LDBL_MAX_EXP__; }; |
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|
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template <typename _Tp> |
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struct __max_exponent10_impl {}; |
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|
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template <> |
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struct __max_exponent10_impl<float> |
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{ static inline constexpr int value = __FLT_MAX_10_EXP__; }; |
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|
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template <> |
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struct __max_exponent10_impl<double> |
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{ static inline constexpr int value = __DBL_MAX_10_EXP__; }; |
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|
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template <> |
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struct __max_exponent10_impl<long double> |
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{ static inline constexpr int value = __LDBL_MAX_10_EXP__; }; |
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|
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template <typename _Tp> |
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struct __min_exponent_impl {}; |
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|
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template <> |
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struct __min_exponent_impl<float> |
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{ static inline constexpr int value = __FLT_MIN_EXP__; }; |
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|
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template <> |
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struct __min_exponent_impl<double> |
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{ static inline constexpr int value = __DBL_MIN_EXP__; }; |
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|
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template <> |
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struct __min_exponent_impl<long double> |
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{ static inline constexpr int value = __LDBL_MIN_EXP__; }; |
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|
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template <typename _Tp> |
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struct __min_exponent10_impl {}; |
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|
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template <> |
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struct __min_exponent10_impl<float> |
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{ static inline constexpr int value = __FLT_MIN_10_EXP__; }; |
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|
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template <> |
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struct __min_exponent10_impl<double> |
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{ static inline constexpr int value = __DBL_MIN_10_EXP__; }; |
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|
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template <> |
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struct __min_exponent10_impl<long double> |
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{ static inline constexpr int value = __LDBL_MIN_10_EXP__; }; |
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|
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template <typename _Tp, bool = is_arithmetic_v<_Tp>> |
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struct __radix_impl {}; |
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|
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template <typename _Tp> |
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struct __radix_impl<_Tp, true> |
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{ |
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static inline constexpr int value |
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= is_floating_point_v<_Tp> ? __FLT_RADIX__ : 2; |
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}; |
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|
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// [num.traits.util], numeric utility traits |
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template <template <typename> class _Trait, typename _Tp> |
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struct __value_exists : __value_exists_impl<_Trait, _Tp> {}; |
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|
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template <template <typename> class _Trait, typename _Tp> |
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inline constexpr bool __value_exists_v = __value_exists<_Trait, _Tp>::value; |
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|
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template <template <typename> class _Trait, typename _Tp, typename _Up = _Tp> |
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inline constexpr _Up |
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__value_or(_Up __def = _Up()) noexcept |
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{ |
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if constexpr (__value_exists_v<_Trait, _Tp>) |
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return static_cast<_Up>(_Trait<_Tp>::value); |
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else |
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return __def; |
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} |
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|
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template <typename _Tp, bool = is_arithmetic_v<_Tp>> |
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struct __norm_min_impl {}; |
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|
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template <typename _Tp> |
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struct __norm_min_impl<_Tp, true> |
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{ static inline constexpr _Tp value = 1; }; |
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|
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template <> |
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struct __norm_min_impl<float, true> |
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{ static inline constexpr float value = __FLT_MIN__; }; |
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|
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template <> |
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struct __norm_min_impl<double, true> |
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{ static inline constexpr double value = __DBL_MIN__; }; |
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|
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template <> |
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struct __norm_min_impl<long double, true> |
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{ static inline constexpr long double value = __LDBL_MIN__; }; |
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|
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template <typename _Tp> |
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struct __denorm_min_impl : __norm_min_impl<_Tp> {}; |
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|
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#if __FLT_HAS_DENORM__ |
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template <> |
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struct __denorm_min_impl<float> |
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{ static inline constexpr float value = __FLT_DENORM_MIN__; }; |
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#endif |
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|
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#if __DBL_HAS_DENORM__ |
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template <> |
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struct __denorm_min_impl<double> |
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{ static inline constexpr double value = __DBL_DENORM_MIN__; }; |
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#endif |
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|
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#if __LDBL_HAS_DENORM__ |
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template <> |
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struct __denorm_min_impl<long double> |
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{ static inline constexpr long double value = __LDBL_DENORM_MIN__; }; |
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#endif |
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|
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template <typename _Tp> |
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struct __epsilon_impl {}; |
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|
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template <> |
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struct __epsilon_impl<float> |
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{ static inline constexpr float value = __FLT_EPSILON__; }; |
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|
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template <> |
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struct __epsilon_impl<double> |
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{ static inline constexpr double value = __DBL_EPSILON__; }; |
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|
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template <> |
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struct __epsilon_impl<long double> |
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{ static inline constexpr long double value = __LDBL_EPSILON__; }; |
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|
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template <typename _Tp, bool = is_arithmetic_v<_Tp>> |
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struct __finite_min_impl {}; |
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|
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template <typename _Tp> |
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struct __finite_min_impl<_Tp, true> |
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{ |
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static inline constexpr _Tp value |
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= is_unsigned_v<_Tp> ? _Tp() |
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: -2 * (_Tp(1) << __digits_impl<_Tp>::value - 1); |
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}; |
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|
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template <> |
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struct __finite_min_impl<float, true> |
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{ static inline constexpr float value = -__FLT_MAX__; }; |
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|
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template <> |
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struct __finite_min_impl<double, true> |
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{ static inline constexpr double value = -__DBL_MAX__; }; |
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|
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template <> |
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struct __finite_min_impl<long double, true> |
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{ static inline constexpr long double value = -__LDBL_MAX__; }; |
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|
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template <typename _Tp, bool = is_arithmetic_v<_Tp>> |
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struct __finite_max_impl {}; |
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|
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template <typename _Tp> |
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struct __finite_max_impl<_Tp, true> |
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{ static inline constexpr _Tp value = ~__finite_min_impl<_Tp>::value; }; |
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|
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template <> |
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struct __finite_max_impl<float, true> |
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{ static inline constexpr float value = __FLT_MAX__; }; |
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|
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template <> |
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struct __finite_max_impl<double, true> |
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{ static inline constexpr double value = __DBL_MAX__; }; |
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|
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template <> |
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struct __finite_max_impl<long double, true> |
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{ static inline constexpr long double value = __LDBL_MAX__; }; |
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|
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template <typename _Tp> |
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struct __infinity_impl {}; |
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|
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#if __FLT_HAS_INFINITY__ |
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template <> |
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struct __infinity_impl<float> |
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{ static inline constexpr float value = __builtin_inff(); }; |
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#endif |
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|
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#if __DBL_HAS_INFINITY__ |
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template <> |
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struct __infinity_impl<double> |
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{ static inline constexpr double value = __builtin_inf(); }; |
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#endif |
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|
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#if __LDBL_HAS_INFINITY__ |
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template <> |
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struct __infinity_impl<long double> |
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{ static inline constexpr long double value = __builtin_infl(); }; |
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#endif |
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|
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template <typename _Tp> |
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struct __quiet_NaN_impl {}; |
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|
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#if __FLT_HAS_QUIET_NAN__ |
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template <> |
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struct __quiet_NaN_impl<float> |
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{ static inline constexpr float value = __builtin_nanf(""); }; |
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#endif |
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|
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#if __DBL_HAS_QUIET_NAN__ |
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template <> |
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struct __quiet_NaN_impl<double> |
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{ static inline constexpr double value = __builtin_nan(""); }; |
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#endif |
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|
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#if __LDBL_HAS_QUIET_NAN__ |
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template <> |
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struct __quiet_NaN_impl<long double> |
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{ static inline constexpr long double value = __builtin_nanl(""); }; |
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#endif |
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|
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template <typename _Tp, bool = is_floating_point_v<_Tp>> |
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struct __reciprocal_overflow_threshold_impl {}; |
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|
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template <typename _Tp> |
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struct __reciprocal_overflow_threshold_impl<_Tp, true> |
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{ |
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// This typically yields a subnormal value. Is this incorrect for |
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// flush-to-zero configurations? |
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static constexpr _Tp _S_search(_Tp __ok, _Tp __overflows) |
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{ |
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const _Tp __mid = (__ok + __overflows) / 2; |
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// 1/__mid without -ffast-math is not a constant expression if it |
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// overflows. Therefore divide 1 by the radix before division. |
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// Consequently finite_max (the threshold) must be scaled by the |
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// same value. |
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if (__mid == __ok || __mid == __overflows) |
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return __ok; |
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else if (_Tp(1) / (__radix_impl<_Tp>::value * __mid) |
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<= __finite_max_impl<_Tp>::value / __radix_impl<_Tp>::value) |
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return _S_search(__mid, __overflows); |
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else |
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return _S_search(__ok, __mid); |
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} |
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|
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static inline constexpr _Tp value |
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= _S_search(_Tp(1.01) / __finite_max_impl<_Tp>::value, |
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_Tp(0.99) / __finite_max_impl<_Tp>::value); |
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}; |
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|
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template <typename _Tp, bool = is_floating_point_v<_Tp>> |
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struct __round_error_impl {}; |
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|
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template <typename _Tp> |
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struct __round_error_impl<_Tp, true> |
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{ static inline constexpr _Tp value = 0.5; }; |
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|
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template <typename _Tp> |
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struct __signaling_NaN_impl {}; |
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|
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#if __FLT_HAS_QUIET_NAN__ |
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template <> |
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struct __signaling_NaN_impl<float> |
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{ static inline constexpr float value = __builtin_nansf(""); }; |
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#endif |
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|
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#if __DBL_HAS_QUIET_NAN__ |
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template <> |
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struct __signaling_NaN_impl<double> |
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{ static inline constexpr double value = __builtin_nans(""); }; |
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#endif |
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|
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#if __LDBL_HAS_QUIET_NAN__ |
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template <> |
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struct __signaling_NaN_impl<long double> |
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{ static inline constexpr long double value = __builtin_nansl(""); }; |
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#endif |
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|
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// [num.traits.val], numeric distinguished value traits |
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template <typename _Tp> |
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struct __denorm_min : __denorm_min_impl<remove_cv_t<_Tp>> {}; |
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|
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template <typename _Tp> |
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struct __epsilon : __epsilon_impl<remove_cv_t<_Tp>> {}; |
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|
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template <typename _Tp> |
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struct __finite_max : __finite_max_impl<remove_cv_t<_Tp>> {}; |
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|
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template <typename _Tp> |
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struct __finite_min : __finite_min_impl<remove_cv_t<_Tp>> {}; |
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|
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template <typename _Tp> |
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struct __infinity : __infinity_impl<remove_cv_t<_Tp>> {}; |
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|
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template <typename _Tp> |
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struct __norm_min : __norm_min_impl<remove_cv_t<_Tp>> {}; |
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|
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template <typename _Tp> |
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struct __quiet_NaN : __quiet_NaN_impl<remove_cv_t<_Tp>> {}; |
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|
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template <typename _Tp> |
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struct __reciprocal_overflow_threshold |
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: __reciprocal_overflow_threshold_impl<remove_cv_t<_Tp>> {}; |
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|
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template <typename _Tp> |
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struct __round_error : __round_error_impl<remove_cv_t<_Tp>> {}; |
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|
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template <typename _Tp> |
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struct __signaling_NaN : __signaling_NaN_impl<remove_cv_t<_Tp>> {}; |
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|
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template <typename _Tp> |
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inline constexpr auto __denorm_min_v = __denorm_min<_Tp>::value; |
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|
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template <typename _Tp> |
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inline constexpr auto __epsilon_v = __epsilon<_Tp>::value; |
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|
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template <typename _Tp> |
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inline constexpr auto __finite_max_v = __finite_max<_Tp>::value; |
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|
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template <typename _Tp> |
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inline constexpr auto __finite_min_v = __finite_min<_Tp>::value; |
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|
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template <typename _Tp> |
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inline constexpr auto __infinity_v = __infinity<_Tp>::value; |
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|
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template <typename _Tp> |
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inline constexpr auto __norm_min_v = __norm_min<_Tp>::value; |
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|
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template <typename _Tp> |
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inline constexpr auto __quiet_NaN_v = __quiet_NaN<_Tp>::value; |
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|
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template <typename _Tp> |
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inline constexpr auto __reciprocal_overflow_threshold_v |
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= __reciprocal_overflow_threshold<_Tp>::value; |
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|
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template <typename _Tp> |
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inline constexpr auto __round_error_v = __round_error<_Tp>::value; |
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|
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template <typename _Tp> |
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inline constexpr auto __signaling_NaN_v = __signaling_NaN<_Tp>::value; |
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|
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// [num.traits.char], numeric characteristics traits |
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template <typename _Tp> |
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struct __digits : __digits_impl<remove_cv_t<_Tp>> {}; |
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|
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template <typename _Tp> |
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struct __digits10 : __digits10_impl<remove_cv_t<_Tp>> {}; |
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|
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template <typename _Tp> |
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struct __max_digits10 : __max_digits10_impl<remove_cv_t<_Tp>> {}; |
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|
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template <typename _Tp> |
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struct __max_exponent : __max_exponent_impl<remove_cv_t<_Tp>> {}; |
| 449 |
|
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template <typename _Tp> |
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struct __max_exponent10 : __max_exponent10_impl<remove_cv_t<_Tp>> {}; |
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|
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template <typename _Tp> |
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struct __min_exponent : __min_exponent_impl<remove_cv_t<_Tp>> {}; |
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|
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template <typename _Tp> |
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struct __min_exponent10 : __min_exponent10_impl<remove_cv_t<_Tp>> {}; |
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|
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template <typename _Tp> |
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struct __radix : __radix_impl<remove_cv_t<_Tp>> {}; |
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|
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template <typename _Tp> |
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inline constexpr auto __digits_v = __digits<_Tp>::value; |
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|
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template <typename _Tp> |
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inline constexpr auto __digits10_v = __digits10<_Tp>::value; |
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|
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template <typename _Tp> |
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inline constexpr auto __max_digits10_v = __max_digits10<_Tp>::value; |
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|
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template <typename _Tp> |
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inline constexpr auto __max_exponent_v = __max_exponent<_Tp>::value; |
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|
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template <typename _Tp> |
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inline constexpr auto __max_exponent10_v = __max_exponent10<_Tp>::value; |
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|
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template <typename _Tp> |
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inline constexpr auto __min_exponent_v = __min_exponent<_Tp>::value; |
| 479 |
|
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template <typename _Tp> |
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inline constexpr auto __min_exponent10_v = __min_exponent10<_Tp>::value; |
| 482 |
|
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template <typename _Tp> |
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inline constexpr auto __radix_v = __radix<_Tp>::value; |
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|
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// mkretz's extensions |
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// TODO: does GCC tell me? __GCC_IEC_559 >= 2 is not the right answer |
| 488 |
template <typename _Tp> |
| 489 |
struct __has_iec559_storage_format : true_type {}; |
| 490 |
|
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template <typename _Tp> |
| 492 |
inline constexpr bool __has_iec559_storage_format_v |
| 493 |
= __has_iec559_storage_format<_Tp>::value; |
| 494 |
|
| 495 |
/* To propose: |
| 496 |
If __has_iec559_behavior<__quiet_NaN, T> is true the following holds: |
| 497 |
- nan == nan is false |
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- isnan(nan) is true |
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- isnan(nan + x) is true |
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- isnan(inf/inf) is true |
| 501 |
- isnan(0/0) is true |
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- isunordered(nan, x) is true |
| 503 |
|
| 504 |
If __has_iec559_behavior<__infinity, T> is true the following holds (x is |
| 505 |
neither nan nor inf): |
| 506 |
- isinf(inf) is true |
| 507 |
- isinf(inf + x) is true |
| 508 |
- isinf(1/0) is true |
| 509 |
*/ |
| 510 |
template <template <typename> class _Trait, typename _Tp> |
| 511 |
struct __has_iec559_behavior : false_type {}; |
| 512 |
|
| 513 |
template <template <typename> class _Trait, typename _Tp> |
| 514 |
inline constexpr bool __has_iec559_behavior_v |
| 515 |
= __has_iec559_behavior<_Trait, _Tp>::value; |
| 516 |
|
| 517 |
#if !__FINITE_MATH_ONLY__ |
| 518 |
#if __FLT_HAS_QUIET_NAN__ |
| 519 |
template <> |
| 520 |
struct __has_iec559_behavior<__quiet_NaN, float> : true_type {}; |
| 521 |
#endif |
| 522 |
|
| 523 |
#if __DBL_HAS_QUIET_NAN__ |
| 524 |
template <> |
| 525 |
struct __has_iec559_behavior<__quiet_NaN, double> : true_type {}; |
| 526 |
#endif |
| 527 |
|
| 528 |
#if __LDBL_HAS_QUIET_NAN__ |
| 529 |
template <> |
| 530 |
struct __has_iec559_behavior<__quiet_NaN, long double> : true_type {}; |
| 531 |
#endif |
| 532 |
|
| 533 |
#if __FLT_HAS_INFINITY__ |
| 534 |
template <> |
| 535 |
struct __has_iec559_behavior<__infinity, float> : true_type {}; |
| 536 |
#endif |
| 537 |
|
| 538 |
#if __DBL_HAS_INFINITY__ |
| 539 |
template <> |
| 540 |
struct __has_iec559_behavior<__infinity, double> : true_type {}; |
| 541 |
#endif |
| 542 |
|
| 543 |
#if __LDBL_HAS_INFINITY__ |
| 544 |
template <> |
| 545 |
struct __has_iec559_behavior<__infinity, long double> : true_type {}; |
| 546 |
#endif |
| 547 |
|
| 548 |
#ifdef __SUPPORT_SNAN__ |
| 549 |
#if __FLT_HAS_QUIET_NAN__ |
| 550 |
template <> |
| 551 |
struct __has_iec559_behavior<__signaling_NaN, float> : true_type {}; |
| 552 |
#endif |
| 553 |
|
| 554 |
#if __DBL_HAS_QUIET_NAN__ |
| 555 |
template <> |
| 556 |
struct __has_iec559_behavior<__signaling_NaN, double> : true_type {}; |
| 557 |
#endif |
| 558 |
|
| 559 |
#if __LDBL_HAS_QUIET_NAN__ |
| 560 |
template <> |
| 561 |
struct __has_iec559_behavior<__signaling_NaN, long double> : true_type {}; |
| 562 |
#endif |
| 563 |
|
| 564 |
#endif |
| 565 |
#endif // __FINITE_MATH_ONLY__ |
| 566 |
|
| 567 |
} // namespace std |
