87 lines
2.3 KiB
C++
87 lines
2.3 KiB
C++
// (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
|
|
|
|
|
|
|