// (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 | |