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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