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1// (C) Copyright John Maddock 2005-2021.2// (C) Copyright Matt Borland 2021.3// Use, modification and distribution are subject to the4// Boost Software License, Version 1.0. (See accompanying file5// LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)6 7#ifndef BOOST_MATH_CCMATH_HYPOT_HPP8#define BOOST_MATH_CCMATH_HYPOT_HPP9 10#include <boost/math/ccmath/detail/config.hpp>11 12#ifdef BOOST_MATH_NO_CCMATH13#error "The header <boost/math/hypot.hpp> can only be used in C++17 and later."14#endif15 16#include <array>17#include <boost/math/tools/config.hpp>18#include <boost/math/tools/promotion.hpp>19#include <boost/math/ccmath/sqrt.hpp>20#include <boost/math/ccmath/abs.hpp>21#include <boost/math/ccmath/isinf.hpp>22#include <boost/math/ccmath/isnan.hpp>23#include <boost/math/ccmath/detail/swap.hpp>24 25namespace boost::math::ccmath {26 27namespace detail {28 29template <typename T>30constexpr T hypot_impl(T x, T y) noexcept31{32 x = boost::math::ccmath::abs(x);33 y = boost::math::ccmath::abs(y);34 35 if (y > x)36 {37 boost::math::ccmath::detail::swap(x, y);38 }39 40 if(x * std::numeric_limits<T>::epsilon() >= y)41 {42 return x;43 }44 45 T rat = y / x;46 return x * boost::math::ccmath::sqrt(1 + rat * rat);47}48 49} // Namespace detail50 51template <typename Real, std::enable_if_t<!std::is_integral_v<Real>, bool> = true>52constexpr Real hypot(Real x, Real y) noexcept53{54 if(BOOST_MATH_IS_CONSTANT_EVALUATED(x))55 {56 if (boost::math::ccmath::abs(x) == static_cast<Real>(0))57 {58 return boost::math::ccmath::abs(y);59 }60 else if (boost::math::ccmath::abs(y) == static_cast<Real>(0))61 {62 return boost::math::ccmath::abs(x);63 }64 // Return +inf even if the other argument is NaN65 else if (boost::math::ccmath::isinf(x) || boost::math::ccmath::isinf(y))66 {67 return std::numeric_limits<Real>::infinity();68 }69 else if (boost::math::ccmath::isnan(x))70 {71 return x;72 }73 else if (boost::math::ccmath::isnan(y))74 {75 return y;76 }77 78 return boost::math::ccmath::detail::hypot_impl(x, y);79 }80 else81 {82 using std::hypot;83 return hypot(x, y);84 }85}86 87template <typename T1, typename T2>88constexpr auto hypot(T1 x, T2 y) noexcept89{90 if(BOOST_MATH_IS_CONSTANT_EVALUATED(x))91 {92 using promoted_type = boost::math::tools::promote_args_t<T1, T2>;93 return boost::math::ccmath::hypot(static_cast<promoted_type>(x), static_cast<promoted_type>(y));94 }95 else96 {97 using std::hypot;98 return hypot(x, y);99 }100}101 102constexpr float hypotf(float x, float y) noexcept103{104 return boost::math::ccmath::hypot(x, y);105}106 107#ifndef BOOST_MATH_NO_LONG_DOUBLE_MATH_FUNCTIONS108constexpr long double hypotl(long double x, long double y) noexcept109{110 return boost::math::ccmath::hypot(x, y);111}112#endif113 114} // Namespaces115 116#endif // BOOST_MATH_CCMATH_HYPOT_HPP117