| 1 | // boost\math\tools\promotion.hpp |
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| 2 | |
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| 3 | // Copyright John Maddock 2006. |
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| 4 | // Copyright Paul A. Bristow 2006. |
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| 5 | // Copyright Matt Borland 2023. |
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| 6 | |
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| 7 | // Use, modification and distribution are subject to the |
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| 8 | // Boost Software License, Version 1.0. |
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| 9 | // (See accompanying file LICENSE_1_0.txt |
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| 10 | // or copy at http://www.boost.org/LICENSE_1_0.txt) |
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| 11 | |
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| 12 | // Promote arguments functions to allow math functions to have arguments |
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| 13 | // provided as integer OR real (floating-point, built-in or UDT) |
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| 14 | // (called ArithmeticType in functions that use promotion) |
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| 15 | // that help to reduce the risk of creating multiple instantiations. |
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| 16 | // Allows creation of an inline wrapper that forwards to a foo(RT, RT) function, |
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| 17 | // so you never get to instantiate any mixed foo(RT, IT) functions. |
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| 18 | |
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| 19 | #ifndef BOOST_MATH_PROMOTION_HPP |
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| 20 | #define BOOST_MATH_PROMOTION_HPP |
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| 21 | |
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| 22 | #ifdef _MSC_VER |
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| 23 | #pragma once |
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| 24 | #endif |
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| 25 | |
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| 26 | #include <boost/math/tools/config.hpp> |
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| 27 | #include <type_traits> |
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| 28 | |
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| 29 | #if defined __has_include |
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| 30 | # if __cplusplus > 202002L || (defined(_MSVC_LANG) && _MSVC_LANG > 202002L) |
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| 31 | # if __has_include (<stdfloat>) |
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| 32 | # include <stdfloat> |
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| 33 | # endif |
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| 34 | # endif |
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| 35 | #endif |
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| 36 | |
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| 37 | namespace boost |
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| 38 | { |
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| 39 | namespace math |
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| 40 | { |
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| 41 | namespace tools |
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| 42 | { |
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| 43 | // If either T1 or T2 is an integer type, |
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| 44 | // pretend it was a double (for the purposes of further analysis). |
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| 45 | // Then pick the wider of the two floating-point types |
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| 46 | // as the actual signature to forward to. |
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| 47 | // For example: |
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| 48 | // foo(int, short) -> double foo(double, double); |
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| 49 | // foo(int, float) -> double foo(double, double); |
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| 50 | // Note: NOT float foo(float, float) |
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| 51 | // foo(int, double) -> foo(double, double); |
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| 52 | // foo(double, float) -> double foo(double, double); |
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| 53 | // foo(double, float) -> double foo(double, double); |
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| 54 | // foo(any-int-or-float-type, long double) -> foo(long double, long double); |
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| 55 | // but ONLY float foo(float, float) is unchanged. |
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| 56 | // So the only way to get an entirely float version is to call foo(1.F, 2.F), |
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| 57 | // But since most (all?) the math functions convert to double internally, |
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| 58 | // probably there would not be the hoped-for gain by using float here. |
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| 59 | |
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| 60 | // This follows the C-compatible conversion rules of pow, etc |
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| 61 | // where pow(int, float) is converted to pow(double, double). |
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| 62 | |
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| 63 | template <class T> |
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| 64 | struct promote_arg |
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| 65 | { // If T is integral type, then promote to double. |
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| 66 | using type = typename std::conditional<std::is_integral<T>::value, double, T>::type; |
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| 67 | }; |
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| 68 | // These full specialisations reduce std::conditional usage and speed up |
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| 69 | // compilation: |
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| 70 | template <> struct promote_arg<float> { using type = float; }; |
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| 71 | template <> struct promote_arg<double>{ using type = double; }; |
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| 72 | template <> struct promote_arg<long double> { using type = long double; }; |
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| 73 | template <> struct promote_arg<int> { using type = double; }; |
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| 74 | |
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| 75 | #ifdef __STDCPP_FLOAT16_T__ |
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| 76 | template <> struct promote_arg<std::float16_t> { using type = std::float16_t; }; |
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| 77 | #endif |
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| 78 | #ifdef __STDCPP_FLOAT32_T__ |
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| 79 | template <> struct promote_arg<std::float32_t> { using type = std::float32_t; }; |
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| 80 | #endif |
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| 81 | #ifdef __STDCPP_FLOAT64_T__ |
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| 82 | template <> struct promote_arg<std::float64_t> { using type = std::float64_t; }; |
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| 83 | #endif |
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| 84 | #ifdef __STDCPP_FLOAT128_T__ |
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| 85 | template <> struct promote_arg<std::float128_t> { using type = std::float128_t; }; |
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| 86 | #endif |
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| 87 | |
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| 88 | template <typename T> |
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| 89 | using promote_arg_t = typename promote_arg<T>::type; |
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| 90 | |
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| 91 | template <class T1, class T2> |
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| 92 | struct promote_args_2 |
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| 93 | { // Promote, if necessary, & pick the wider of the two floating-point types. |
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| 94 | // for both parameter types, if integral promote to double. |
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| 95 | using T1P = typename promote_arg<T1>::type; // T1 perhaps promoted. |
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| 96 | using T2P = typename promote_arg<T2>::type; // T2 perhaps promoted. |
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| 97 | using intermediate_type = typename std::conditional< |
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| 98 | std::is_floating_point<T1P>::value && std::is_floating_point<T2P>::value, // both T1P and T2P are floating-point? |
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| 99 | #ifdef __STDCPP_FLOAT128_T__ |
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| 100 | typename std::conditional<std::is_same<std::float128_t, T1P>::value || std::is_same<std::float128_t, T2P>::value, // either long double? |
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| 101 | std::float128_t, |
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| 102 | #endif |
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| 103 | #ifdef BOOST_MATH_USE_FLOAT128 |
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| 104 | typename std::conditional<std::is_same<__float128, T1P>::value || std::is_same<__float128, T2P>::value, // either long double? |
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| 105 | __float128, |
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| 106 | #endif |
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| 107 | typename std::conditional<std::is_same<long double, T1P>::value || std::is_same<long double, T2P>::value, // either long double? |
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| 108 | long double, // then result type is long double. |
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| 109 | #ifdef __STDCPP_FLOAT64_T__ |
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| 110 | typename std::conditional<std::is_same<std::float64_t, T1P>::value || std::is_same<std::float64_t, T2P>::value, // either float64? |
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| 111 | std::float64_t, // then result type is float64_t. |
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| 112 | #endif |
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| 113 | typename std::conditional<std::is_same<double, T1P>::value || std::is_same<double, T2P>::value, // either double? |
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| 114 | double, // result type is double. |
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| 115 | #ifdef __STDCPP_FLOAT32_T__ |
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| 116 | typename std::conditional<std::is_same<std::float32_t, T1P>::value || std::is_same<std::float32_t, T2P>::value, // either float32? |
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| 117 | std::float32_t, // then result type is float32_t. |
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| 118 | #endif |
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| 119 | float // else result type is float. |
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| 120 | >::type |
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| 121 | #ifdef BOOST_MATH_USE_FLOAT128 |
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| 122 | >::type |
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| 123 | #endif |
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| 124 | #ifdef __STDCPP_FLOAT128_T__ |
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| 125 | >::type |
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| 126 | #endif |
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| 127 | #ifdef __STDCPP_FLOAT64_T__ |
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| 128 | >::type |
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| 129 | #endif |
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| 130 | #ifdef __STDCPP_FLOAT32_T__ |
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| 131 | >::type |
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| 132 | #endif |
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| 133 | >::type, |
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| 134 | // else one or the other is a user-defined type: |
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| 135 | typename std::conditional<!std::is_floating_point<T2P>::value && std::is_convertible<T1P, T2P>::value, T2P, T1P>::type>::type; |
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| 136 | |
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| 137 | #ifdef __STDCPP_FLOAT64_T__ |
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| 138 | // If long doubles are doubles then we should prefer to use std::float64_t when available |
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| 139 | using type = std::conditional_t<(sizeof(double) == sizeof(long double) && std::is_same<intermediate_type, long double>::value), std::float64_t, intermediate_type>; |
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| 140 | #else |
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| 141 | using type = intermediate_type; |
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| 142 | #endif |
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| 143 | }; // promote_arg2 |
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| 144 | // These full specialisations reduce std::conditional usage and speed up |
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| 145 | // compilation: |
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| 146 | template <> struct promote_args_2<float, float> { using type = float; }; |
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| 147 | template <> struct promote_args_2<double, double>{ using type = double; }; |
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| 148 | template <> struct promote_args_2<long double, long double> { using type = long double; }; |
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| 149 | template <> struct promote_args_2<int, int> { using type = double; }; |
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| 150 | template <> struct promote_args_2<int, float> { using type = double; }; |
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| 151 | template <> struct promote_args_2<float, int> { using type = double; }; |
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| 152 | template <> struct promote_args_2<int, double> { using type = double; }; |
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| 153 | template <> struct promote_args_2<double, int> { using type = double; }; |
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| 154 | template <> struct promote_args_2<int, long double> { using type = long double; }; |
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| 155 | template <> struct promote_args_2<long double, int> { using type = long double; }; |
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| 156 | template <> struct promote_args_2<float, double> { using type = double; }; |
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| 157 | template <> struct promote_args_2<double, float> { using type = double; }; |
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| 158 | template <> struct promote_args_2<float, long double> { using type = long double; }; |
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| 159 | template <> struct promote_args_2<long double, float> { using type = long double; }; |
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| 160 | template <> struct promote_args_2<double, long double> { using type = long double; }; |
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| 161 | template <> struct promote_args_2<long double, double> { using type = long double; }; |
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| 162 | |
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| 163 | #ifdef __STDCPP_FLOAT128_T__ |
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| 164 | template <> struct promote_args_2<int, std::float128_t> { using type = std::float128_t; }; |
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| 165 | template <> struct promote_args_2<std::float128_t, int> { using type = std::float128_t; }; |
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| 166 | template <> struct promote_args_2<std::float128_t, float> { using type = std::float128_t; }; |
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| 167 | template <> struct promote_args_2<float, std::float128_t> { using type = std::float128_t; }; |
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| 168 | template <> struct promote_args_2<std::float128_t, double> { using type = std::float128_t; }; |
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| 169 | template <> struct promote_args_2<double, std::float128_t> { using type = std::float128_t; }; |
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| 170 | template <> struct promote_args_2<std::float128_t, long double> { using type = std::float128_t; }; |
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| 171 | template <> struct promote_args_2<long double, std::float128_t> { using type = std::float128_t; }; |
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| 172 | |
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| 173 | #ifdef __STDCPP_FLOAT16_T__ |
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| 174 | template <> struct promote_args_2<std::float128_t, std::float16_t> { using type = std::float128_t; }; |
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| 175 | template <> struct promote_args_2<std::float16_t, std::float128_t> { using type = std::float128_t; }; |
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| 176 | #endif |
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| 177 | |
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| 178 | #ifdef __STDCPP_FLOAT32_T__ |
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| 179 | template <> struct promote_args_2<std::float128_t, std::float32_t> { using type = std::float128_t; }; |
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| 180 | template <> struct promote_args_2<std::float32_t, std::float128_t> { using type = std::float128_t; }; |
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| 181 | #endif |
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| 182 | |
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| 183 | #ifdef __STDCPP_FLOAT64_T__ |
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| 184 | template <> struct promote_args_2<std::float128_t, std::float64_t> { using type = std::float128_t; }; |
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| 185 | template <> struct promote_args_2<std::float64_t, std::float128_t> { using type = std::float128_t; }; |
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| 186 | #endif |
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| 187 | |
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| 188 | template <> struct promote_args_2<std::float128_t, std::float128_t> { using type = std::float128_t; }; |
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| 189 | #endif |
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| 190 | |
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| 191 | #ifdef __STDCPP_FLOAT64_T__ |
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| 192 | template <> struct promote_args_2<int, std::float64_t> { using type = std::float64_t; }; |
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| 193 | template <> struct promote_args_2<std::float64_t, int> { using type = std::float64_t; }; |
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| 194 | template <> struct promote_args_2<std::float64_t, float> { using type = std::float64_t; }; |
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| 195 | template <> struct promote_args_2<float, std::float64_t> { using type = std::float64_t; }; |
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| 196 | template <> struct promote_args_2<std::float64_t, double> { using type = std::float64_t; }; |
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| 197 | template <> struct promote_args_2<double, std::float64_t> { using type = std::float64_t; }; |
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| 198 | template <> struct promote_args_2<std::float64_t, long double> { using type = long double; }; |
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| 199 | template <> struct promote_args_2<long double, std::float64_t> { using type = long double; }; |
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| 200 | |
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| 201 | #ifdef __STDCPP_FLOAT16_T__ |
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| 202 | template <> struct promote_args_2<std::float64_t, std::float16_t> { using type = std::float64_t; }; |
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| 203 | template <> struct promote_args_2<std::float16_t, std::float64_t> { using type = std::float64_t; }; |
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| 204 | #endif |
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| 205 | |
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| 206 | #ifdef __STDCPP_FLOAT32_T__ |
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| 207 | template <> struct promote_args_2<std::float64_t, std::float32_t> { using type = std::float64_t; }; |
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| 208 | template <> struct promote_args_2<std::float32_t, std::float64_t> { using type = std::float64_t; }; |
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| 209 | #endif |
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| 210 | |
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| 211 | template <> struct promote_args_2<std::float64_t, std::float64_t> { using type = std::float64_t; }; |
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| 212 | #endif |
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| 213 | |
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| 214 | #ifdef __STDCPP_FLOAT32_T__ |
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| 215 | template <> struct promote_args_2<int, std::float32_t> { using type = std::float32_t; }; |
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| 216 | template <> struct promote_args_2<std::float32_t, int> { using type = std::float32_t; }; |
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| 217 | template <> struct promote_args_2<std::float32_t, float> { using type = std::float32_t; }; |
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| 218 | template <> struct promote_args_2<float, std::float32_t> { using type = std::float32_t; }; |
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| 219 | template <> struct promote_args_2<std::float32_t, double> { using type = double; }; |
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| 220 | template <> struct promote_args_2<double, std::float32_t> { using type = double; }; |
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| 221 | template <> struct promote_args_2<std::float32_t, long double> { using type = long double; }; |
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| 222 | template <> struct promote_args_2<long double, std::float32_t> { using type = long double; }; |
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| 223 | |
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| 224 | #ifdef __STDCPP_FLOAT16_T__ |
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| 225 | template <> struct promote_args_2<std::float32_t, std::float16_t> { using type = std::float32_t; }; |
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| 226 | template <> struct promote_args_2<std::float16_t, std::float32_t> { using type = std::float32_t; }; |
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| 227 | #endif |
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| 228 | |
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| 229 | template <> struct promote_args_2<std::float32_t, std::float32_t> { using type = std::float32_t; }; |
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| 230 | #endif |
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| 231 | |
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| 232 | #ifdef __STDCPP_FLOAT16_T__ |
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| 233 | template <> struct promote_args_2<int, std::float16_t> { using type = std::float16_t; }; |
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| 234 | template <> struct promote_args_2<std::float16_t, int> { using type = std::float16_t; }; |
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| 235 | template <> struct promote_args_2<std::float16_t, float> { using type = float; }; |
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| 236 | template <> struct promote_args_2<float, std::float16_t> { using type = float; }; |
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| 237 | template <> struct promote_args_2<std::float16_t, double> { using type = double; }; |
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| 238 | template <> struct promote_args_2<double, std::float16_t> { using type = double; }; |
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| 239 | template <> struct promote_args_2<std::float16_t, long double> { using type = long double; }; |
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| 240 | template <> struct promote_args_2<long double, std::float16_t> { using type = long double; }; |
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| 241 | |
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| 242 | template <> struct promote_args_2<std::float16_t, std::float16_t> { using type = std::float16_t; }; |
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| 243 | #endif |
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| 244 | |
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| 245 | template <typename T, typename U> |
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| 246 | using promote_args_2_t = typename promote_args_2<T, U>::type; |
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| 247 | |
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| 248 | template <class T1, class T2=float, class T3=float, class T4=float, class T5=float, class T6=float> |
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| 249 | struct promote_args |
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| 250 | { |
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| 251 | using type = typename promote_args_2< |
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| 252 | typename std::remove_cv<T1>::type, |
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| 253 | typename promote_args_2< |
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| 254 | typename std::remove_cv<T2>::type, |
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| 255 | typename promote_args_2< |
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| 256 | typename std::remove_cv<T3>::type, |
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| 257 | typename promote_args_2< |
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| 258 | typename std::remove_cv<T4>::type, |
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| 259 | typename promote_args_2< |
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| 260 | typename std::remove_cv<T5>::type, typename std::remove_cv<T6>::type |
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| 261 | >::type |
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| 262 | >::type |
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| 263 | >::type |
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| 264 | >::type |
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| 265 | >::type; |
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| 266 | |
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| 267 | #if defined(BOOST_MATH_NO_LONG_DOUBLE_MATH_FUNCTIONS) |
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| 268 | // |
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| 269 | // Guard against use of long double if it's not supported: |
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| 270 | // |
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| 271 | static_assert((0 == std::is_same<type, long double>::value), "Sorry, but this platform does not have sufficient long double support for the special functions to be reliably implemented." ); |
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| 272 | #endif |
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| 273 | }; |
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| 274 | |
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| 275 | template <class T1, class T2=float, class T3=float, class T4=float, class T5=float, class T6=float> |
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| 276 | using promote_args_t = typename promote_args<T1, T2, T3, T4, T5, T6>::type; |
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| 277 | |
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| 278 | // |
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| 279 | // This struct is the same as above, but has no static assert on long double usage, |
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| 280 | // it should be used only on functions that can be implemented for long double |
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| 281 | // even when std lib support is missing or broken for that type. |
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| 282 | // |
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| 283 | template <class T1, class T2=float, class T3=float, class T4=float, class T5=float, class T6=float> |
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| 284 | struct promote_args_permissive |
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| 285 | { |
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| 286 | using type = typename promote_args_2< |
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| 287 | typename std::remove_cv<T1>::type, |
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| 288 | typename promote_args_2< |
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| 289 | typename std::remove_cv<T2>::type, |
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| 290 | typename promote_args_2< |
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| 291 | typename std::remove_cv<T3>::type, |
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| 292 | typename promote_args_2< |
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| 293 | typename std::remove_cv<T4>::type, |
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| 294 | typename promote_args_2< |
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| 295 | typename std::remove_cv<T5>::type, typename std::remove_cv<T6>::type |
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| 296 | >::type |
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| 297 | >::type |
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| 298 | >::type |
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| 299 | >::type |
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| 300 | >::type; |
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| 301 | }; |
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| 302 | |
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| 303 | template <class T1, class T2=float, class T3=float, class T4=float, class T5=float, class T6=float> |
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| 304 | using promote_args_permissive_t = typename promote_args_permissive<T1, T2, T3, T4, T5, T6>::type; |
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| 305 | |
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| 306 | } // namespace tools |
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| 307 | } // namespace math |
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| 308 | } // namespace boost |
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| 309 | |
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| 310 | #endif // BOOST_MATH_PROMOTION_HPP |
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| 311 | |
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| 312 | |
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