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From: gyro@kestrel.edu (Scott Layson Burson)
Newsgroups: comp.std.c++
Subject: Re: "module" facility for top-level namespace control
Keywords: namespace, module
Message-ID: <1991Apr24.100733.19988@kestrel.edu>
Date: 24 Apr 91 10:07:33 GMT
References: <5143@lupine.NCD.COM> <1991Apr21.014746.3526@kestrel.edu> <5176@lupine.NCD.COM>
Distribution: comp.std.c++
Organization: Kestrel Institute, Palo Alto, CA
Lines: 54

In article <5176@lupine.NCD.COM> rfg@NCD.COM (Ron Guilmette) writes:
>In article <1991Apr21.014746.3526@kestrel.edu> gyro@kestrel.edu (Scott Layson Burson) writes:
>>... Also, if there were also some sort of
>>`use' declaration, I think I would really want it to work only on
>>modules; otherwise its definition has to be that it makes the names of
>>only static members visible, because it wouldn't make sense to make
>>the names of normal (nonstatic) members visible...
>
>I disagree.
>
>I don't see anything wrong with  a generalized "opening of the scope"
>which applies to both static and non-static members.  In some cases,
>it might actually be useful.  For example:
>
>	struct S {
>		int data_member;
>		void func_member (void);
>	};
>
>	int S::*data_mbr_ptr;
>	int S::*func_mbr_ptr;
>
>	int i;
>
>	void example ()
>	{
>		use S;		// scope opener
>
>		i = S::data_member;	// error - no object specified
>		i = data_member;	// error - no object specified
>
>		S::func_member();	// error - no object specified
>		func_member ();		// error - no object specified
>
>		data_mbr_ptr = &S::data_member;		// OK
>		data_mbr_ptr = &data_member;		// also OK
>
>		func_mbr_ptr = &S::func_member;		// OK
>		func_mbr_ptr = func_member;		// also OK
>	}

In the language as it stands (the ARM, anyway), the only way to create
a pointer to member is with the `&A::b' syntax.  I vigorously object
to any proposal that would make it possible to create them without the
qualifier, because I think that they are very much unlike pointers
(the term "pointer to member" notwithstanding).

I also think this example is pretty contrived.

I stand by my original opinion: the scope opener makes sense only on
static members.

-- Scott
Gyro@Reasoning.COM