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From: sakkinen@tukki.jyu.fi (Markku Sakkinen)
Newsgroups: comp.lang.c++
Subject: Re: scope of friend identifiers
Message-ID: <1990Aug17.123746.8855@tukki.jyu.fi>
Date: 7 Aug 90 06:35:39 GMT
References: <5708@darkstar.ucsc.edu>
Reply-To: sakkinen@jytko.jyu.fi (Markku Sakkinen)
Organization: University of Jyvaskyla, Finland
Lines: 57

Note2: Third trial to post!
Note1: This is the second posting of an article that apparently
disappeared while the news software was out of order here
for three days. Sorry if somebody receives it twice.

In article <5708@darkstar.ucsc.edu> daniel@terra.ucsc.edu (Daniel Edelson) writes:
>The rules governing names introduced in friend
>declarations appear somewhat ambiguous according
>to [E&S 90], section 11.4. It says 
>
>	``If a class or function mentioned as a 
>	friend has not been declared its name is 
>	entered in the same scope as the name of 
>	the class containing the declaration.''
>
>
>Does this imply that a friend declaration in a nested
>class declares a member function of the enclosing class?
>E.g.,
>
>	struct out {
>		struct in {
>			friend void frfunc();
>		};
>	};
>
>According to the rule, the name frfunc is scoped to out.

"Nested classes" in C++ are a pure deception; they are _not_
in the scope of the enclosing class. Thus, the definition
of 'in' is actually in an outer scope, and 'frfunc' belongs
to the same scope, without the least ambiguity.

> [...]

The above should answer also most of the rest of the questions
in the original posting, or make them irrelevant.

>Then again, in section 3.2 the discussion of class scope says that
>``A name first declared by a friend declaration belongs to the 
>global scope;'' which, if true, contradicts the 11.4 statement and
>renders this discussion moot. Is there a diffinitive answer as to
>which section is correct?

My version of the 2.0 Ref. Man. (from sometime in 1989) says in #3.2:
"... its name belongs to the enclosing scope; the same is true
for a name declared by a friend declaration (#11.4)."
There is thus a no contradiction in _that_ version,
but if yours is newer, it makes one wonder.

Markku Sakkinen
Department of Computer Science
University of Jyvaskyla (a's with umlauts)
Seminaarinkatu 15
SF-40100 Jyvaskyla (umlauts again)
Finland
          SAKKINEN@FINJYU.bitnet (alternative network address)