X-Git-Url: https://git.donarmstrong.com/?a=blobdiff_plain;f=lily%2Fprotected-scm.cc;h=3a16254187a05b0b7880a53ec9250c47071e8aee;hb=2fef7b7eb7ac5d7a2ed237bf22a6ec6fe5d946d9;hp=a9fabdc4f2e6fa69803b4c2aaa2c3583039d2154;hpb=3af0951f9a11677240efa6228683dd4fcea13eaf;p=lilypond.git

diff --git a/lily/protected-scm.cc b/lily/protected-scm.cc
index a9fabdc4f2..3a16254187 100644
--- a/lily/protected-scm.cc
+++ b/lily/protected-scm.cc
@@ -86,3 +86,11 @@ Protected_scm::operator SCM & ()
 
   return *SCM_CARLOC (object_);
 }
+
+bool
+Protected_scm::is_bound () const
+{
+  if (SCM_CONSP (object_))
+    return !SCM_UNBNDP (SCM_CAR (object_));
+  return !SCM_UNBNDP (object_);
+}