Why can't everything be overloaded in C++?

Question

It is reasonable that sizeof and typeid cannot be overloaded, but I can't see the harm in overloading ?:, .* and .. Are there technical reasons for this?

Answer 1

To quote Bjarne Stroustrup:

There is no fundamental reason to disallow overloading of ?:. I just didn't see the need to introduce the special case of overloading a ternary operator. Note that a function overloading expr1?expr2:expr3 would not be able to guarantee that only one of expr2 and expr3 was executed.

...

Operator . (dot) could in principle be overloaded using the same technique as used for ->. However, doing so can lead to questions about whether an operation is meant for the object overloading . or an object referred to by . ... This problem can be solved in several ways. At the time of standardization, it was not obvious which way would be best.

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