yhe@caen.engin.umich.edu (youda he) (01/15/89)
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.