method

remove_instance_variable

v1_8_7_330 - Show latest stable - 0 notes - Class: Object

remove_instance_variable(p1) public

Removes the named instance variable from obj, returning that variable’s value.

class Dummy
  attr_reader :var
  def initialize
    @var = 99
  end
  def remove
    remove_instance_variable(:@var)
  end
end
d = Dummy.new
d.var      #=> 99
d.remove   #=> 99
d.var      #=> nil

Show source

/*
 *  call-seq:
 *     obj.remove_instance_variable(symbol)    => obj
 *  
 *  Removes the named instance variable from <i>obj</i>, returning that
 *  variable's value.
 *     
 *     class Dummy
 *       attr_reader :var
 *       def initialize
 *         @var = 99
 *       end
 *       def remove
 *         remove_instance_variable(:@var)
 *       end
 *     end
 *     d = Dummy.new
 *     d.var      #=> 99
 *     d.remove   #=> 99
 *     d.var      #=> nil
 */

VALUE
rb_obj_remove_instance_variable(obj, name)
    VALUE obj, name;
{
    VALUE val = Qnil;
    ID id = rb_to_id(name);

    if (!OBJ_TAINTED(obj) && rb_safe_level() >= 4)
	rb_raise(rb_eSecurityError, "Insecure: can't modify instance variable");
    if (OBJ_FROZEN(obj)) rb_error_frozen("object");
    if (!rb_is_instance_id(id)) {
	rb_name_error(id, "`%s' is not allowed as an instance variable name", rb_id2name(id));
    }

    switch (TYPE(obj)) {
      case T_OBJECT:
      case T_CLASS:
      case T_MODULE:
	if (ROBJECT(obj)->iv_tbl && st_delete(ROBJECT(obj)->iv_tbl, (st_data_t*)&id, &val)) {
	    return val;
	}
	break;
      default:
	if (FL_TEST(obj, FL_EXIVAR) || rb_special_const_p(obj)) {
	    if (generic_ivar_remove(obj, id, &val)) {
		return val;
	    }
	}
	break;
    }
    rb_name_error(id, "instance variable %s not defined", rb_id2name(id));
    return Qnil;		/* not reached */
}

remove_instance_variable

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