+IMPLEMENT_SIMPLE_SMOBS (Duration);
+int
+Duration::print_smob (SCM s, SCM port, scm_print_state *)
+{
+ Duration *r = (Duration *) SCM_CELL_WORD_1 (s);
+
+ scm_puts ("#<Duration ", port);
+ scm_display (scm_makfrom0str (r->to_string ().c_str ()), port);
+ scm_puts (" >", port);