From 150b67f88729d46cf514df430edf7be2c14d861c Mon Sep 17 00:00:00 2001
From: Timo Koch <timo.koch@iws.uni-stuttgart.de>
Date: Thu, 22 Feb 2018 14:21:15 +0100
Subject: [PATCH] [math] Improve signature of harmonic/geometricMean
Add constexpr (not for geometricMean which uses std::sqrt) and noexcept.
Static assert the requirements on the input arguments, they have to be numbers.
---
dumux/common/math.hh | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/dumux/common/math.hh b/dumux/common/math.hh
index 905d5aab72..e076ffac73 100644
--- a/dumux/common/math.hh
+++ b/dumux/common/math.hh
@@ -42,8 +42,10 @@ namespace Dumux
* \param y The second input value
*/
template <class Scalar>
-Scalar harmonicMean(Scalar x, Scalar y)
+constexpr Scalar harmonicMean(Scalar x, Scalar y) noexcept
{
+ static_assert(Dune::IsNumber<Scalar>::value, "The arguments x and y have to be numbers!");
+
if (x*y <= 0)
return 0;
return (2*x*y)/(x + y);
@@ -55,10 +57,13 @@ Scalar harmonicMean(Scalar x, Scalar y)
*
* \param x The first input value
* \param y The second input value
+ * \note as std::sqrt is not constexpr this function is not constexpr
*/
template <class Scalar>
-Scalar geometricMean(Scalar x, Scalar y)
+Scalar geometricMean(Scalar x, Scalar y) noexcept
{
+ static_assert(Dune::IsNumber<Scalar>::value, "The arguments x and y have to be numbers!");
+
if (x*y <= 0)
return 0;
using std::sqrt;
--
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