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From: yhe@caen.engin.umich.edu (youda he)
Newsgroups: comp.lang.c++
Subject: Zortech C++ overloading
Message-ID: <40dcec16.1285f@maize.engin.umich.edu>
Date: 14 Jan 89 17:47:00 GMT
Reply-To: yhe@caen.engin.umich.edu (youda he)
Organization: caen
Lines: 30

Overloading operator<< and operator>> use user supplied data type is pain
in Zortech C++, consider the following example:

file foo.cpp:
class foo {
     ...
public:
     friend istream& operator<<(istream&, foo&);
};

file bar.cpp:
class bar {
     ...
public:
     friend istream& operator<<(istream&, bar&);
};

compile both files will generate two _lshift in each file, and try
to link foo+bar there will be problems in find proper _lshift. If I put all
"operator<<" definition in one file, only the first one will be cast
as _lshift, the others will get a much longer name to indicate the proper
usage, to occupy the first _lshift, I had to define a dummy class, put
it's definition at the top of the "operator<<" file.

I believe the solution will be to expand all overload functions to its full
name, starting from the first one.

The second question: should all friend functions be implicitly considered
as overload? after look at the libg++ code, I think GNU C++ overload all
friend function automatically.