tb: add A_CANT to dsp method

externals/tb/block_delay~/block_delay~.c

@@ -95,5 +95,5 @@ void block_delay_tilde_setup(void)
 	block_delay_tilde_class = class_new(gensym("block_delay~"), (t_newmethod)block_delay_tilde_new, (t_method)block_delay_tilde_free,
 		sizeof(t_block_delay), 0, A_DEFFLOAT, 0);
 	class_addmethod(block_delay_tilde_class, nullfn, gensym("signal"), 0);
-	class_addmethod(block_delay_tilde_class, (t_method)block_delay_tilde_dsp, gensym("dsp"), 0);
+	class_addmethod(block_delay_tilde_class, (t_method)block_delay_tilde_dsp, gensym("dsp"), A_CANT, 0);
 }

externals/tb/erfc~/erfc~.c

@@ -60,5 +60,5 @@ void erfc_tilde_setup(void)
     erfc_class = class_new(gensym("erfc~"), (t_newmethod)erfc_new, 0,
         sizeof(t_erfc), 0, A_DEFFLOAT, 0);
     CLASS_MAINSIGNALIN(erfc_class, t_erfc, x_f);
-    class_addmethod(erfc_class, (t_method)erfc_dsp, gensym("dsp"), 0);
+    class_addmethod(erfc_class, (t_method)erfc_dsp, gensym("dsp"), A_CANT, 0);
 }

externals/tb/erf~/erf~.c

@@ -60,5 +60,5 @@ void erf_tilde_setup(void)
     erf_class = class_new(gensym("erf~"), (t_newmethod)erf_new, 0,
         sizeof(t_erf), 0, A_DEFFLOAT, 0);
     CLASS_MAINSIGNALIN(erf_class, t_erf, x_f);
-    class_addmethod(erf_class, (t_method)erf_dsp, gensym("dsp"), 0);
+    class_addmethod(erf_class, (t_method)erf_dsp, gensym("dsp"), A_CANT, 0);
 }

externals/tb/volctl~/volctl~.c

@@ -363,7 +363,7 @@ void volctl_tilde_setup(void)
     volctl_class = class_new(gensym("volctl~"), (t_newmethod)volctl_new, 
 							 (t_method)volctl_free, sizeof(t_volctl), 0, A_GIMME, 0);
     CLASS_MAINSIGNALIN(volctl_class, t_volctl, x_f);
-    class_addmethod(volctl_class, (t_method)volctl_dsp, gensym("dsp"), 0);
+    class_addmethod(volctl_class, (t_method)volctl_dsp, gensym("dsp"), A_CANT, 0);
     class_addmethod(volctl_class, (t_method)volctl_set, gensym("f1"),A_FLOAT,0);
     class_settip(volctl_class,gensym("signal"));
 }