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From: chris_tebbe AT yahoo DOT com (Chris)
Newsgroups: comp.os.msdos.djgpp
Subject: Help with Operator Overloading
Date: 31 Mar 2004 03:33:49 -0800
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To: djgpp AT delorie DOT com
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Reply-To: djgpp AT delorie DOT com

As a result of my last posting, I apparently have a little catching up
to do on the "new" C++ relative to updating my old programs.  So,
here's another one for the DJGPP warriors:

In my header file, I have overloaded "*" as follows:

    friend Matrix & operator*(FLOAT_TYPE, Matrix &); // multiply
scalar & matrix

Of course, this compiles nicely.  In implementation as follows:

    double rate;
    Matrix DeltaWeight(4,4);
    Matrix weight(4,4);
...
    weight=weight+(Matrix&)(rate*(Matrix&)DeltaWeight);
...

and I get the following error:

connect.cc:88: error: ISO C++ says that `Matrix& operator*(double,
Matrix&)' and `operator*' are ambiguous even though the worst
conversion for the former is better than the worst conversion for the
latter

In my header file, I have also overloaded the double() function to
allow the casting of a 1x1 matrix into a double, but here I have
explicitly cast DeltaWeight as a Matrix as well as the result of the
multiplication.

As always, any help is appreciated.

--Chris