From 134d9f19ab5dbe5262c158090c95cb77aeaf9959 Mon Sep 17 00:00:00 2001
From: Wolfgang Bangerth <bangerth@math.tamu.edu>
Date: Wed, 15 Mar 2006 20:57:26 +0000
Subject: [PATCH] Implement is_finite

git-svn-id: https://svn.dealii.org/trunk@12605 0785d39b-7218-0410-832d-ea1e28bc413d
---
 deal.II/base/source/config.cc | 35 +++++++++++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)
 create mode 100644 deal.II/base/source/config.cc

diff --git a/deal.II/base/source/config.cc b/deal.II/base/source/config.cc
new file mode 100644
index 0000000000..4d8ec7b70e
--- /dev/null
+++ b/deal.II/base/source/config.cc
@@ -0,0 +1,35 @@
+//---------------------------------------------------------------------------
+//    $Id$
+//    Version: $Name$
+//
+//    Copyright (C) 2006 by the deal.II authors
+//
+//    This file is subject to QPL and may not be  distributed
+//    without copyright and license information. Please refer
+//    to the file deal.II/doc/license.html for the  text  and
+//    further information on this license.
+//
+//---------------------------------------------------------------------------
+
+
+#include <base/config.h>
+#include <cmath>
+#include <limits>
+
+
+namespace deal_II_numbers 
+{
+  bool is_finite (const double x) 
+  {
+#ifdef DEAL_II_HAVE_ISFINITE
+    return std::isfinite (x);
+#else
+				     // check against infinities. not
+				     // that if x is a NaN, then both
+				     // comparisons will be false
+    return ((x >= std::numeric_limits<double>::min())
+	    &&
+	    (x <= std::numeric_limits<double>::max()));
+#endif
+  }
+}
-- 
2.39.5