From 98ca36e8f585cc54acd3396be7d13e0a7ade2892 Mon Sep 17 00:00:00 2001
From: Frederic Bouvier <fredfgfs01@free.fr>
Date: Wed, 26 Sep 2012 08:36:56 +0200
Subject: [PATCH] MSVC has no std::isnan

---
 simgear/math/SGGeod.hxx | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/simgear/math/SGGeod.hxx b/simgear/math/SGGeod.hxx
index 54b2f37f..2ab2b107 100644
--- a/simgear/math/SGGeod.hxx
+++ b/simgear/math/SGGeod.hxx
@@ -20,6 +20,10 @@
 
 #include <simgear/constants.h>
 
+#ifndef _MSC_VER
+using std::isnan;
+#endif
+
 // #define SG_GEOD_NATIVE_DEGREE
 
 /// Class representing a geodetic location
@@ -352,7 +356,7 @@ inline
 bool
 SGGeod::isValid() const
 {
-  if (std::isnan(_lon) || std::isnan(_lat)) return false;
+  if (isnan(_lon) || isnan(_lat)) return false;
 #ifdef SG_GEOD_NATIVE_DEGREE
   return (_lon >= -180.0) && (_lon <= 180.0) &&
   (_lat >= -90.0) && (_lat <= 90.0);