core/src/main/java/org/jruby/RubyBasicObject.java
public RubyArray to_a(ThreadContext context) {
        Ruby runtime = context.runtime;
        runtime.getWarnings().warn(ID.DEPRECATED_METHOD, "default 'to_a' will be obsolete");
        return runtime.newArray(this);
    }
/** rb_any_to_a
     *
     *  call-seq:
     *     obj.to_a -> anArray
     *
     *  Returns an array representation of <i>obj</i>. For objects of class
     *  <code>Object</code> and others that don't explicitly override the
     *  method, the return value is an array containing <code>self</code>.
     *  However, this latter behavior will soon be obsolete.
     *
     *     self.to_a       #=> -:1: warning: default `to_a' will be obsolete
     *     "hello".to_a    #=> ["hello"]
     *     Time.new.to_a   #=> [39, 54, 8, 9, 4, 2003, 3, 99, true, "CDT"]
     *
     *  The default to_a method is deprecated.
     */


Returns an array representation of obj. For objects of class
Object and others that don't explicitly override the
method, the return value is an array containing self.
However, this latter behavior will soon be obsolete.



The default to_a method is deprecated.
Returns an array representation of obj . For objects of class Object and others that don ' t explicitly override the method the return value is an array containing self . However this latter behavior will soon be obsolete . The default to_a method is deprecated .
public RubyArray to_a(ThreadContext context) {
        Ruby runtime = context.runtime;
        runtime.getWarnings().warn(ID.DEPRECATED_METHOD, "default 'to_a' will be obsolete");
        return runtime.newArray(this);
    }
public RubyArray to_a ( ThreadContext context ) { Ruby runtime = context . runtime ; runtime . getWarnings ( ) . warn ( ID . DEPRECATED_METHOD , "default 'to_a' will be obsolete" ) ; return runtime . newArray ( this ) ; }
rb_any_to_a
  call-seq:
     obj.to_a -> anArray
rb_any_to_a call - seq : obj . to_a - > anArray