Operators which can not be overloaded in C++
Any operator which operates on value(s) can be overloaded.
For example,
c = a + b;
As the operator + operates on two values, it can be easily overloaded.
Now look at the unary operator *. It operates on the variable name, not on the value.
b = *a;
where a is not a value, but a name.
Similarly the following operators can not be overloaded.
sizeof - The operator to find the size of a variable in memory
? -The ternary operator
:: – The scope resolution operator
. – The operator to access class members
-> – The operator to access class members from a class pointer type variable
* – The indirection operator
Not sure I follow. How are the semantics of ‘*a’ any different than ‘b + a’ ? In both cases the data being processed is the *value* of a – in the dereferencing case, the value is just interpreted as an address. I don’t see how the *name* of a is an operand in either case.
I think it is just a c++ design decision, for which operators to allow overloading. In different languages (LISP, Haskell, whatever) very different decisions were taken – I can’t see how it’s any semantic constraint (these operators operate on ‘name’ whereas others on ‘value’).
Hi Ofek,
thanks for your comment and interest in http://techievibes.com.
From Stroustrup’s “The C++ Programming Language”, 3rd Edn, he says these operators take name rather than a value as their second argument and provide the primary means of referring to members.
Hence, overloading these operators can lead to subtleties.
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