shared_scm       5233 src/extlib.c     ScmObj shared_scm;
shared_scm       5244 src/extlib.c     shared_scm = SCM_ARGREF(3);
shared_scm       5245 src/extlib.c     if (!SCM_BOOLP(shared_scm)) Scm_Error("boolean required, but got %S", shared_scm);
shared_scm       5246 src/extlib.c     shared = SCM_BOOL_VALUE(shared_scm);