Why does C++ need the scope resolution operator?

Question

(I know what the scope resolution operator does, and how and when to use it.)

Why does C++ have the :: operator, instead of using the . operator for this purpose? Java doesn't have a separate operator, and works fine. Is there some difference between C++ and Java that means C++ requires a separate operator in order to be parsable?

My only guess is that :: is needed for precedence reasons, but I can't think why it needs to have higher precedence than, say, .. The only situation I can think it would is so that something like

a.b::c;

would be parsed as

a.(b::c);

, but I can't think of any situation in which syntax like this would be legal anyway.

Maybe it's just a case of "they do different things, so they might as well look different". But that doesn't explain why :: has higher precedence than ..

Answer 1

I always assumed C++ dot/:: usage was a style choice, to make code easier to read. As the OP writes "they do different things, so should look different."

Coming from C++, long ago, to C#, I found using only dots confusing. I was used to seeing A::doStuff(); B.doStuff();, and knowing the first is a regular function, in a namespace, and the second is a member function on instance B.

C++ is maybe my fifth language, after Basic, assembly, Pascal and Fortran, so I don't think it's first language syndrome, and I'm more a C# programmer now. But, IMHO, if you've used both, C++-style double-colon for namespaces reads better. I feel like Java/C# chose dots for both to (successfully) ease the front of the learning curve.