projects / ceph.git / blame
| Commit | Line | Data |
|---|---|---|
| 7c673cae FG |
1 | // (C) Copyright John Maddock 2005-2006. |
| 2 | // Use, modification and distribution are subject to the | |
| 3 | // Boost Software License, Version 1.0. (See accompanying file | |
| 4 | // LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) | |
| 5 | ||
| 6 | #ifndef BOOST_MATH_HYPOT_INCLUDED | |
| 7 | #define BOOST_MATH_HYPOT_INCLUDED | |
| 8 | ||
| 9 | #ifdef _MSC_VER | |
| 10 | #pragma once | |
| 11 | #endif | |
| 12 | ||
| 13 | #include <boost/math/tools/config.hpp> | |
| 14 | #include <boost/math/tools/precision.hpp> | |
| 15 | #include <boost/math/policies/error_handling.hpp> | |
| 16 | #include <boost/math/special_functions/math_fwd.hpp> | |
| 7c673cae | 17 | #include <algorithm> // for swap |
| 1e59de90 | 18 | #include <cmath> |
| 7c673cae FG |
19 | |
| 20 | namespace boost{ namespace math{ namespace detail{ | |
| 21 | ||
| 22 | template <class T, class Policy> | |
| 23 | T hypot_imp(T x, T y, const Policy& pol) | |
| 24 | { | |
| 25 | // | |
| 26 | // Normalize x and y, so that both are positive and x >= y: | |
| 27 | // | |
| 28 | using std::fabs; using std::sqrt; // ADL of std names | |
| 29 | ||
| 30 | x = fabs(x); | |
| 31 | y = fabs(y); | |
| 32 | ||
| 1e59de90 | 33 | #ifdef _MSC_VER |
| 7c673cae FG |
34 | #pragma warning(push) |
| 35 | #pragma warning(disable: 4127) | |
| 36 | #endif | |
| 37 | // special case, see C99 Annex F: | |
| 38 | if(std::numeric_limits<T>::has_infinity | |
| 39 | && ((x == std::numeric_limits<T>::infinity()) | |
| 40 | || (y == std::numeric_limits<T>::infinity()))) | |
| 41 | return policies::raise_overflow_error<T>("boost::math::hypot<%1%>(%1%,%1%)", 0, pol); | |
| 1e59de90 | 42 | #ifdef _MSC_VER |
| 7c673cae FG |
43 | #pragma warning(pop) |
| 44 | #endif | |
| 45 | ||
| 46 | if(y > x) | |
| 47 | (std::swap)(x, y); | |
| 48 | ||
| 49 | if(x * tools::epsilon<T>() >= y) | |
| 50 | return x; | |
| 51 | ||
| 52 | T rat = y / x; | |
| 53 | return x * sqrt(1 + rat*rat); | |
| 54 | } // template <class T> T hypot(T x, T y) | |
| 55 | ||
| 56 | } | |
| 57 | ||
| 58 | template <class T1, class T2> | |
| 59 | inline typename tools::promote_args<T1, T2>::type | |
| 60 | hypot(T1 x, T2 y) | |
| 61 | { | |
| 62 | typedef typename tools::promote_args<T1, T2>::type result_type; | |
| 63 | return detail::hypot_imp( | |
| 64 | static_cast<result_type>(x), static_cast<result_type>(y), policies::policy<>()); | |
| 65 | } | |
| 66 | ||
| 67 | template <class T1, class T2, class Policy> | |
| 68 | inline typename tools::promote_args<T1, T2>::type | |
| 69 | hypot(T1 x, T2 y, const Policy& pol) | |
| 70 | { | |
| 71 | typedef typename tools::promote_args<T1, T2>::type result_type; | |
| 72 | return detail::hypot_imp( | |
| 73 | static_cast<result_type>(x), static_cast<result_type>(y), pol); | |
| 74 | } | |
| 75 | ||
| 76 | } // namespace math | |
| 77 | } // namespace boost | |
| 78 | ||
| 79 | #endif // BOOST_MATH_HYPOT_INCLUDED | |
| 80 | ||
| 81 | ||
| 82 |