I disagree and I couldn't disagree more. In mathematics, we're perfectly ?!? using + for integer, float, complex, vector and matrix addition (and the combinations of them) and * for integer, float, complex, vector, vector and scalar, and matrix multiplication. One who doesn't understand what the "code" - mathematical notation - means should blame oneself for not understanding the algorithm, not the "designer" for making the "language" - mathematical conventions - unappropriate.
Albeit Brian Hurt's comment about operator overloading making more harm than good in C++, I believe that overloading simply has to be used appropriately - it's like saying pointers are bad because they can introduce memory leaks and null references, and division is bad because it can raise Division_by_zero exceptions.
Like a saying for magic goes, "There is no black magic or white magic, there is only magic. It's classification depends on the intentions of the caster!" Any tool given to a programmer can be used either to his advantage or disadvantage. Even in the "best" language, a stupid programmer will programm poor algorithms, so there is no point protecting the programmer from himself (or herself).
Hence, one can hardly say overloading (in general, not only operator overloading) is bad in C++. If designed carefuly and mantained with a bit of common sense, it can result in enormous productivity gain. And, how often does it happen that you don't know what a particular operation means in a three-lines-long numerical calculation involving vectors, floats and matrices? Anyhow, if you DID get lost, then you would equally lose yourself in a mess of *|, +\, %, -| and /. operators. You don't want OCaml be named LISO - Lost In Superfluous Operators.
I believe that operator overloading an d overloading in general can result in great productivity and readability gain. Also, they can improve polymorphism. For example, does it matter if you can't figure out the type of a in length a? Actually, it doesn't - it could be a list, an array, a dynarray, a train or a snake - as long as it "fits" algorithmically, it can be anything.
- Tom