Macro to disable the copy-constructor.

Another toolkit I use has an explicit macro for this, which is nice for readability, so I've borrowed it here.

simgear/sg_inlines.h

@@ -103,4 +103,10 @@ inline void SG_NORMALIZE_RANGE( T &val, const T min, const T max ) {
 // avoid an 'unused parameter' compiler warning.
 #define SG_UNUSED(x) (void)x
 
+// easy way to disable the copy constructor and assignment operator
+// on an object
+#define SG_DISABLE_COPY(Class) \
+    Class(const Class &); \
+    Class &operator=(const Class &);
+   
 #endif // _SG_INLINES_H