[gegl] Hide GeglLookup from C++

[Daniel Sabo <daniels src gnome org>]

commit 2a2c25aa287393388372d03cff2b9f42152dce48
Author: Daniel Sabo <DanielSabo gmail com>
Date:   Fri Oct 11 14:15:01 2013 -0700

    Hide GeglLookup from C++
    
    It uses a zero length array, which is not valid in C++.

 gegl/gegl-lookup.h |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)
---
diff --git a/gegl/gegl-lookup.h b/gegl/gegl-lookup.h
index 7ac9135..6352125 100644
--- a/gegl/gegl-lookup.h
+++ b/gegl/gegl-lookup.h
@@ -21,6 +21,8 @@
 
 G_BEGIN_DECLS
 
+#ifndef __cplusplus
+
 typedef     gfloat (* GeglLookupFunction) (gfloat   value,
                                            gpointer data);
 
@@ -101,6 +103,8 @@ gegl_lookup (GeglLookup *lookup,
   return lookup->table[i];
 }
 
+#endif /* __cplusplus */
+
 G_END_DECLS
 
 #endif