Path: utzoo!attcan!uunet!zephyr.ens.tek.com!uw-beaver!cornell!batcomputer!lijewski
From: lijewski@batcomputer.tn.cornell.edu (Mike Lijewski)
Newsgroups: comp.std.c++
Subject: Re: Scope of static member initializers
Message-ID: <10603@batcomputer.tn.cornell.edu>
Date: 1 Aug 90 12:37:45 GMT
References: <1990Aug1.030632.2273@agate.berkeley.edu>
Reply-To: lijewski@tcgould.tn.cornell.edu (Mike Lijewski)
Organization: Cornell National Supercomputer Facility
Lines: 62

In article <1990Aug1.030632.2273@agate.berkeley.edu> lippin@math.berkeley.edu writes:
>My pet peeve with C++ is that (accordong to CFront and a too-close
>reading of the AT&T language description) initializers for static data
>members of a class are in the public scope, rather than the scope of
>the class.

I don't believe the initializers for static data members of a class are
in the public scope.  Consider the following:

#include <stream.h>

class X {
  public:
  static const int i;
  static const int j;
};

const int X::i = 1;
const int X::j = i;

int main() { cout << "X::i = " << X::i << ", X::j = " << X::j; }

This compiles cleanly with cfront 2.0.  This proves that the initialization
of X::j is done in the scope of the class.  My understanding is that whenever
you define something which is prefixed with classname::, you are in the
scope of `classname'.  This is how you can define member functions outside
of the class declaration and still be within the scope of the class.
 
>class groupmember {
>   public:
>      static const groupmember zero;
>      ...
 
>Zero can only be initialized through a public constructor,

Zero can be initialized with a private constructor.  Embellishing your
class a bit we have:

#include <stream.h>

class groupmember {
    public:
    static const groupmember zero;
    void f() const { cout << "p = " << p << "\n"; }
    private:
    int p;
    groupmember() { p = 1; }
};

groupmember const groupmember::zero = groupmember();

int main() { groupmember::zero.f(); return 0; }  // will print 'p = 1'

Again, this compiles cleanly under cfront 2.0, so the initialization of
groupmember::zero is again in the scope of the class.


-- 
Mike Lijewski  (H)607/277-0394 (W)607/254-8686
Cornell National Supercomputer Facility
ARPA: mjlx@eagle.cnsf.cornell.edu  BITNET: mjlx@cornellf.bitnet
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