| // (C) Copyright John Maddock 2005-2006. |
| // 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_HYPOT_INCLUDED |
| #define BOOST_MATH_HYPOT_INCLUDED |
| |
| #ifdef _MSC_VER |
| #pragma once |
| #endif |
| |
| #include <boost/math/tools/config.hpp> |
| #include <boost/math/tools/precision.hpp> |
| #include <boost/math/policies/error_handling.hpp> |
| #include <boost/math/special_functions/math_fwd.hpp> |
| #include <boost/config/no_tr1/cmath.hpp> |
| #include <algorithm> // for swap |
| |
| #ifdef BOOST_NO_STDC_NAMESPACE |
| namespace std{ using ::sqrt; using ::fabs; } |
| #endif |
| |
| namespace boost{ namespace math{ namespace detail{ |
| |
| template <class T, class Policy> |
| T hypot_imp(T x, T y, const Policy& pol) |
| { |
| // |
| // Normalize x and y, so that both are positive and x >= y: |
| // |
| using std::fabs; using std::sqrt; // ADL of std names |
| |
| x = fabs(x); |
| y = fabs(y); |
| |
| #ifdef BOOST_MSVC |
| #pragma warning(push) |
| #pragma warning(disable: 4127) |
| #endif |
| // special case, see C99 Annex F: |
| if(std::numeric_limits<T>::has_infinity |
| && ((x == std::numeric_limits<T>::infinity()) |
| || (y == std::numeric_limits<T>::infinity()))) |
| return policies::raise_overflow_error<T>("boost::math::hypot<%1%>(%1%,%1%)", 0, pol); |
| #ifdef BOOST_MSVC |
| #pragma warning(pop) |
| #endif |
| |
| if(y > x) |
| (std::swap)(x, y); |
| |
| if(x * tools::epsilon<T>() >= y) |
| return x; |
| |
| T rat = y / x; |
| return x * sqrt(1 + rat*rat); |
| } // template <class T> T hypot(T x, T y) |
| |
| } |
| |
| template <class T1, class T2> |
| inline typename tools::promote_args<T1, T2>::type |
| hypot(T1 x, T2 y) |
| { |
| typedef typename tools::promote_args<T1, T2>::type result_type; |
| return detail::hypot_imp( |
| static_cast<result_type>(x), static_cast<result_type>(y), policies::policy<>()); |
| } |
| |
| template <class T1, class T2, class Policy> |
| inline typename tools::promote_args<T1, T2>::type |
| hypot(T1 x, T2 y, const Policy& pol) |
| { |
| typedef typename tools::promote_args<T1, T2>::type result_type; |
| return detail::hypot_imp( |
| static_cast<result_type>(x), static_cast<result_type>(y), pol); |
| } |
| |
| } // namespace math |
| } // namespace boost |
| |
| #endif // BOOST_MATH_HYPOT_INCLUDED |
| |
| |
| |