X-Git-Url: https://git.donarmstrong.com/?a=blobdiff_plain;f=lily%2Finclude%2Fsmobs.tcc;h=c0a62535f5e4f830200c8b4a249ae955032d414f;hb=47db9a3883d726ca53e2133a3b2298f78dd6a32e;hp=7b5179256709db8570a1137109a6b1f9f14bfa4b;hpb=30203dfe5c45fb9c6255512ba0f8366b322d303f;p=lilypond.git

diff --git a/lily/include/smobs.tcc b/lily/include/smobs.tcc
index 7b51792567..c0a62535f5 100644
--- a/lily/include/smobs.tcc
+++ b/lily/include/smobs.tcc
@@ -1,7 +1,7 @@
 /* -*- C++ -*-
   This file is part of LilyPond, the GNU music typesetter.
 
-  Copyright (C) 2005--2014 Han-Wen Nienhuys <hanwen@xs4all.nl>
+  Copyright (C) 2005--2015 Han-Wen Nienhuys <hanwen@xs4all.nl>
 
   LilyPond is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -128,9 +128,12 @@ void Smob_base<Super>::init ()
 
   if (&Super::free_smob != &Smob_base<Super>::free_smob)
     scm_set_smob_free (smob_tag_, Super::free_smob);
-  // Old GCC versions refuse comparing pointers-to-member-function of
-  // covariant types, so we recast here.
-  if (&Super::mark_smob !=
+  // Old GCC versions get their type lattice for pointers-to-members
+  // tangled up to a degree where we need to typecast _both_ covariant
+  // types in order to be able to compare them.  The other comparisons
+  // are for static member functions and thus are ordinary function
+  // pointers which work without those contortions.
+  if (static_cast<SCM (Super::*)()>(&Super::mark_smob) !=
       static_cast<SCM (Super::*)()>(&Smob_base<Super>::mark_smob))
     scm_set_smob_mark (smob_tag_, Super::mark_trampoline);
   scm_set_smob_print (smob_tag_, Super::print_trampoline);