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|> 
|> Assuming X, Y and Z are class names, how should
|> 
|> 	X::Y::Z::*foo;
|> 
|> be interpreted?
|> 
|> 1. foo is a pointer to member of class ::Y::Z of type X.
|>    ('X' is a decl-specifier and '::Y::Z::*foo' is a declarator)
|> 
|> 2. foo is a pointer to member of class ::Z of type X::Y.
|>    ('X::Y' is a decl-specifier and '::Z::*foo' is a declarator)
|> 
|> 3. X::Y::Z is a decl-specifier and ::*mptr is an error.
|> 

The is a simpler potential ambiguity lurking in the use of "::" in declarations.

	X::f() { ... } 

Is the a declaration of "X::f" (implicitly returning int), or of "::f"
(returning X).  To avoid this ambiguity there is a rule that a declarator
may not begin with "::".  Actually there isn't a rule per se. The grammar
doesn't contain any rules that derive a declarator starting with "::".
And that omission is deliberate.

So answer to the question is that non of the above interpretations
is possible.  X::Y::Z::*foo, is a declartor and since no explicit
typespec is present int is assumed.  This means that you declaring
"foo" as a pointer to int member of X::Y::Z.  

    -- Jerry Schwarz.  

In article <1992Dec15.011359.17235@lucid.com> jss@lucid.com (Jerry Schwarz) writes:
[stuff deleted]
>   The grammar
>   doesn't contain any rules that derive a declarator starting with "::".
>   And that omission is deliberate.

But in ARM section 8.2.3, it says that the declarator representing a
pointer to members has the form

	complete-class-name :: * cv-qualifier-list<opt> D1

And complete-class-name can start with ::. Or is it typo?

--
Yasutoshi (Pochi) Norimatsu      | Never worry about theory as long as
pnori@lsi-j.co.jp                | the machinery does what it's supposed
LSI Japan Co. Ltd., Tokyo, JAPAN | to do.            -- R. A. Heinlein

In article <PNORI.92Dec16132118@hyperion.lsi-j.co.jp>, pnori@lsi-j.co.jp (Pochi NORIMATSU) writes:
|> In article <1992Dec15.011359.17235@lucid.com> jss@lucid.com (Jerry Schwarz) writes:
jss:
|> >   The grammar
|> >   doesn't contain any rules that derive a declarator starting with "::".
|> >   And that omission is deliberate.


pnori:
|> But in ARM section 8.2.3, it says that the declarator representing a
|> pointer to members has the form
|> 
|> 	complete-class-name :: * cv-qualifier-list<opt> D1
|> 
|> And complete-class-name can start with ::. Or is it typo?


pnori is right.  This grammar path does lead to a declarator that begins
with a "::".  I suspect this is an oversight. Since, as the original
item pointed out, it also leads to an ambiguity it is something the
standards committee should address.  I think it should be made illegal
on the grounds of my original comment.

  -- Jerry Schwarz

>>>>> On 16 Dec 92 04:21:18 GMT, pnori@lsi-j.co.jp (Pochi NORIMATSU) said:
pnori> In article <1992Dec15.011359.17235@lucid.com> jss@lucid.com (Jerry Schwarz) writes:
jss> The grammar
jss> doesn't contain any rules that derive a declarator starting with "::".
jss> And that omission is deliberate.

pnori> But in ARM section 8.2.3, it says that the declarator representing a
pnori> pointer to members has the form

pnori> 	complete-class-name :: * cv-qualifier-list<opt> D1

pnori> And complete-class-name can start with ::. Or is it typo?

Do you have a version of the ARM different than mine (1990, 
ISBN 0-201-51459-1...)?

In my book it reads in section 8.2.3, p 135:

	class-name :: * cv-qualifier-list<opt> D1

and class-name is just identifier (17.1 p 387)

when (p 392)
	complete-class-name:
		qualified-class-name
		:: qualified-class-name

and
	qualified-class-name:
		typedef-name
		class-name :: qualified-class-name

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In article <GIROD.92Dec18142728@node_262d6.tele.nokia.fi> girod@tele.nokia.fi (Marc Girod) writes:
>   Do you have a version of the ARM different than mine (1990, 
>   ISBN 0-201-51459-1...)?
>
>   In my book it reads in section 8.2.3, p 135:
>
>	   class-name :: * cv-qualifier-list<opt> D1
>
>   and class-name is just identifier (17.1 p 387)

I have two ARMs :-)

One is the same book as you have, and another is "Reprinted with
corrections May, 1992" version. In the reprinted book, class-name has
been replaced by complete-class-name.

BTW, the definition of ptr-operator in section 17.4 in the older book
is also says that a pointer to members starts with complete-class-name.
Don't you think its confusing?
--
Yasutoshi (Pochi) Norimatsu      | Never worry about theory as long as
pnori@lsi-j.co.jp                | the machinery does what it's supposed
LSI Japan Co. Ltd., Tokyo, JAPAN | to do.            -- R. A. Heinlein