+ // This interface must be exported in shared 64 bit multilib build but
+ // using WXEXPORT with Objective C interfaces doesn't work with old (4.0.1)
+ // gcc when using 10.4 SDK. It does work with newer gcc even in 32 bit
+ // builds but seems to be unnecessary there so to avoid the expense of a
+ // configure check verifying if this does work or not with the current
+ // compiler we just only use it for 64 bit builds where this is always
+ // supported.
+ //
+ // NB: Currently this is the only place where we need to export an
+ // interface but if we need to do it elsewhere we should define a
+ // WXEXPORT_OBJC macro once and reuse it in all places it's needed
+ // instead of duplicating this preprocessor check.
+#ifdef __LP64__
+ WXEXPORT
+#endif // 64 bit builds