Why isn't operator overloading for pointers allowed to work?

Question

As per the comment under this answer, references were introduced primarily to support operator overloading which quotes Bjarne Stroustrup:

References

Answer 1

Why doesn't it work for pointers? Because it's ambiguous. Would

ostream* operator<<(ostream* s, const char* c);

match

cout << 'a';

or

cout << "a";

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Also, you can't use address-of (&) with a temporary. What should this do:

complex a, b, c;
cout << a + b * c;

since b * c is a temporary, and the sum is also.

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