Allen (cc-ed) changed symbols back to objects in draft rev 16 
(https://bugs.ecmascript.org/show_bug.cgi?id=1546#c2), so I guess 
Object(x) will still work in ES6 to test for object types.

- André


> I see. That's unpleasant. In ES5, Object(x) can never throw, and so the
> code paths using |x === Object(x)| are not prepared for a throw. Much old
> code will break.
>
>
> On Mon, Jul 15, 2013 at 8:01 AM, Jeremy Martin <jmar777 at gmail.com  <https://mail.mozilla.org/listinfo/es-discuss>> wrote:
>
> >/  > s === Object(s)
> />/
> />/  This should throw a TypeError.  In the case of a Symbol, `Object(*value*)`
> />/  results in `ToObject(*value*)` [1].  And, in the case of Symbol, ToObject
> />/  should throw a TypeError [2].
> />/
> />/  [1]http://people.mozilla.org/~jorendorff/es6-draft.html#sec-15.2.1.1  <http://people.mozilla.org/%7Ejorendorff/es6-draft.html#sec-15.2.1.1>
> />/  [2]http://people.mozilla.org/~jorendorff/es6-draft.html#sec-9.1.9  <http://people.mozilla.org/%7Ejorendorff/es6-draft.html#sec-9.1.9>
> />/
> />/  On Mon, Jul 15, 2013 at 10:48 AM, Mark S. Miller <erights at google.com  <https://mail.mozilla.org/listinfo/es-discuss>>wrote:
> />/
> />>/  Given that s is a Symbol and b is a Bignum, is
> />>/
> />>/      s === Object(s)
> />>/
> />>/  ?
> />>/
> />>/  Is
> />>/
> />>/      b === Object(b)
> />>/
> />>/   ?
> />>/
> />>/  The reason I ask is that x === Object(x) is often used to distinguish
> />>/  primitive values from objects. The other thing that's often used is typeof,
> />>/  but these uses of typeof usually assume that the full range of possible
> />>/  answers is already known. If we're going to be expanding the typeof
> />>/  answers, then we need guidance on how to write this test now (es5) such
> />>/  that it stays robust.
> />>/
> />>/
> />>/  --
> />>/      Cheers,
> />>/      --MarkM//  <https://mail.mozilla.org/listinfo/es-discuss>
> />>/
> />>/
> />/  --
> />/  Jeremy Martin
> />/  661.312.3853
> />/  http://devsmash.com
> />/  @jmar777
> />/
> /
> -- 
>      Cheers,
>      --MarkM
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Allen (cc-ed) changed symbols back to objects in draft rev 16 
(https://bugs.ecmascript.org/show_bug.cgi?id=1546#c2), so I guess 
`Object(x)` will still work in ES6 to test for object types.