// (C) Copyright John Maddock 2005-2021. // (C) Copyright Matt Borland 2021. // Use, modification and distribution are subject to the // Boost Software License, Version 1.0. (See accompanying file // LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) #ifndef BOOST_MATH_CCMATH_HYPOT_HPP #define BOOST_MATH_CCMATH_HYPOT_HPP #include <boost/math/ccmath/detail/config.hpp> #ifdef BOOST_MATH_NO_CCMATH #error "The header <boost/math/hypot.hpp> can only be used in C++17 and later." #endif #include <array> #include <boost/math/tools/config.hpp> #include <boost/math/tools/promotion.hpp> #include <boost/math/ccmath/sqrt.hpp> #include <boost/math/ccmath/abs.hpp> #include <boost/math/ccmath/isinf.hpp> #include <boost/math/ccmath/isnan.hpp> #include <boost/math/ccmath/detail/swap.hpp> namespace boost::math::ccmath { namespace detail { template <typename T> constexpr T hypot_impl(T x, T y) noexcept { x = boost::math::ccmath::abs(x); y = boost::math::ccmath::abs(y); if (y > x) { boost::math::ccmath::detail::swap(x, y); } if(x * std::numeric_limits<T>::epsilon() >= y) { return x; } T rat = y / x; return x * boost::math::ccmath::sqrt(1 + rat * rat); } } // Namespace detail template <typename Real, std::enable_if_t<!std::is_integral_v<Real>, bool> = true> constexpr Real hypot(Real x, Real y) noexcept { if(BOOST_MATH_IS_CONSTANT_EVALUATED(x)) { if (boost::math::ccmath::abs(x) == static_cast<Real>(0)) { return boost::math::ccmath::abs(y); } else if (boost::math::ccmath::abs(y) == static_cast<Real>(0)) { return boost::math::ccmath::abs(x); } // Return +inf even if the other argument is NaN else if (boost::math::ccmath::isinf(x) || boost::math::ccmath::isinf(y)) { return std::numeric_limits<Real>::infinity(); } else if (boost::math::ccmath::isnan(x)) { return x; } else if (boost::math::ccmath::isnan(y)) { return y; } return boost::math::ccmath::detail::hypot_impl(x, y); } else { using std::hypot; return hypot(x, y); } } template <typename T1, typename T2> constexpr auto hypot(T1 x, T2 y) noexcept { if(BOOST_MATH_IS_CONSTANT_EVALUATED(x)) { using promoted_type = boost::math::tools::promote_args_2_t<T1, T2>; return boost::math::ccmath::hypot(static_cast<promoted_type>(x), static_cast<promoted_type>(y)); } else { using std::hypot; return hypot(x, y); } } constexpr float hypotf(float x, float y) noexcept { return boost::math::ccmath::hypot(x, y); } #ifndef BOOST_MATH_NO_LONG_DOUBLE_MATH_FUNCTIONS constexpr long double hypotl(long double x, long double y) noexcept { return boost::math::ccmath::hypot(x, y); } #endif } // Namespaces #endif // BOOST_MATH_CCMATH_HYPOT_HPP