diff -ruN gdl-0.8.10/src/datatypes.cpp gdl-0.8.10.patched/src/datatypes.cpp
--- gdl-0.8.10/src/datatypes.cpp	2005-07-10 11:00:06.000000000 -0400
+++ gdl-0.8.10.patched/src/datatypes.cpp	2005-08-10 13:07:46.000000000 -0400
@@ -35,19 +35,11 @@
 #include <assert.h>
 
 // on OS X isnan is not defined
-#if defined(__APPLE__) && !defined(isnan)
 
-#ifdef __cplusplus
-extern "C" {
-#endif
-#define      isnan( x )         ( ( sizeof ( x ) == sizeof(double) ) ?  \
-                              __isnand ( x ) :                          \
-                                ( sizeof ( x ) == sizeof( float) ) ?    \
-                              __isnanf ( x ) :                          \
-                              __isnan  ( x ) )
-#ifdef __cplusplus
-}
-#endif
+#if defined(__APPLE__) && !defined(isnan)
+#define isnan( x ) ( ( sizeof ( (x) ) == sizeof( float) ) ?  \
+		     __isnanf ( (float)(x) ) :  \
+		     __isnand  ( (double)(x) ) ) 
 #endif
 
 using namespace std;
diff -ruN gdl-0.8.10/src/math_fun_jmg.cpp gdl-0.8.10.patched/src/math_fun_jmg.cpp
--- gdl-0.8.10/src/math_fun_jmg.cpp	2005-07-10 11:00:06.000000000 -0400
+++ gdl-0.8.10.patched/src/math_fun_jmg.cpp	2005-08-10 13:08:02.000000000 -0400
@@ -31,20 +31,10 @@
 
 // on OS X isfinite is not defined
 #if defined(__APPLE__) && !defined(isfinite)
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-#define      isfinite( x )      ( ( sizeof ( x ) == sizeof(double) ) ?       \
-                              __isfinited ( x ) :                            \
-                                ( sizeof ( x ) == sizeof( float) ) ?         \
-                              __isfinitef ( x ) :                            \
-                              __isfinite  ( x ) )
-#ifdef __cplusplus
-}
+#define isfinite( x ) ( ( sizeof ( (x) ) == sizeof( float) ) ? \
+			__isfinitef ( (float)(x) ) : \
+			__isfinited  ( (double)(x) ) )
 #endif
-#endif
-
 
 using namespace std;