remove_const

VALUE
rb_mod_remove_const(VALUE mod, VALUE name)
{
    const ID id = rb_to_id(name);
    VALUE val;
    st_data_t v, n = id;

    rb_vm_change_state();

    if (!rb_is_const_id(id)) {
	rb_name_error(id, "`%s' is not allowed as a constant name", rb_id2name(id));
    }
    if (!OBJ_UNTRUSTED(mod) && rb_safe_level() >= 4)
	rb_raise(rb_eSecurityError, "Insecure: can't remove constant");
    if (OBJ_FROZEN(mod)) rb_error_frozen("class/module");

    if (RCLASS_IV_TBL(mod) && st_delete(RCLASS_IV_TBL(mod), &n, &v)) {
	val = (VALUE)v;
	if (val == Qundef) {
	    autoload_delete(mod, id);
	    val = Qnil;
	}
	return val;
    }
    if (rb_const_defined_at(mod, id)) {
	rb_name_error(id, "cannot remove %s::%s",
		 rb_class2name(mod), rb_id2name(id));
    }
    rb_name_error(id, "constant %s::%s not defined",
		  rb_class2name(mod), rb_id2name(id));
    return Qnil;		/* not reached */
}