Imported Upstream version 1.49.0upstream/1.49.0

1 files changed, 61 insertions, 0 deletions

diff --git a/boost/math/special_functions/powm1.hpp b/boost/math/special_functions/powm1.hpp
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+++ b/boost/math/special_functions/powm1.hpp
@@ -0,0 +1,61 @@
+//  (C) Copyright John Maddock 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_POWM1
+#define BOOST_MATH_POWM1
+
+#ifdef _MSC_VER
+#pragma once
+#endif
+
+#include <boost/math/special_functions/log1p.hpp>
+#include <boost/math/special_functions/expm1.hpp>
+#include <boost/math/special_functions/math_fwd.hpp>
+#include <boost/assert.hpp>
+
+namespace boost{ namespace math{ namespace detail{
+
+template <class T, class Policy>
+inline T powm1_imp(const T a, const T z, const Policy& pol)
+{
+   BOOST_MATH_STD_USING
+
+   if((fabs(a) < 1) || (fabs(z) < 1))
+   {
+      T p = log(a) * z;
+      if(fabs(p) < 2)
+         return boost::math::expm1(p, pol);
+      // otherwise fall though:
+   }
+   return pow(a, z) - 1;
+}
+
+} // detail
+
+template <class T1, class T2>
+inline typename tools::promote_args<T1, T2>::type 
+   powm1(const T1 a, const T2 z)
+{
+   typedef typename tools::promote_args<T1, T2>::type result_type;
+   return detail::powm1_imp(static_cast<result_type>(a), static_cast<result_type>(z), policies::policy<>());
+}
+
+template <class T1, class T2, class Policy>
+inline typename tools::promote_args<T1, T2>::type 
+   powm1(const T1 a, const T2 z, const Policy& pol)
+{
+   typedef typename tools::promote_args<T1, T2>::type result_type;
+   return detail::powm1_imp(static_cast<result_type>(a), static_cast<result_type>(z), pol);
+}
+
+} // namespace math
+} // namespace boost
+
+#endif // BOOST_MATH_POWM1
+
+
+
+
+