obj.dup → an_object

Produces a shallow copy of obj—the instance variables of obj are copied, but not the objects they reference. dup copies the tainted state of obj. See also the discussion under Object#clone. In general, clone and dup may have different semantics in descendent classes. While clone is used to duplicate an object, including its internal state, dup typically uses the class of the descendent object to create the new instance.

This method may have class-specific behavior. If so, that behavior will be documented under the #initialize_copy method of the class.

Source Code

/*
*  call-seq:
*     obj.dup -> an_object
*  
*  Produces a shallow copy of <i>obj</i>---the instance variables of
*  <i>obj</i> are copied, but not the objects they reference.
*  <code>dup</code> copies the tainted state of <i>obj</i>. See also
*  the discussion under <code>Object#clone</code>. In general,
*  <code>clone</code> and <code>dup</code> may have different semantics
*  in descendent classes. While <code>clone</code> is used to duplicate
*  an object, including its internal state, <code>dup</code> typically
*  uses the class of the descendent object to create the new instance.
*
*  This method may have class-specific behavior.  If so, that
*  behavior will be documented under the #+initialize_copy+ method of
*  the class.
*/

VALUE
rb_obj_dup(obj)
   VALUE obj;
{
   VALUE dup;

   if (rb_special_const_p(obj)) {
       rb_raise(rb_eTypeError, "can't dup %s", rb_obj_classname(obj));
   }
   dup = rb_obj_alloc(rb_obj_class(obj));
   init_copy(dup, obj);

   return dup;
}