Does C++11 allow vector?

Question

Container requirements have changed from C++03 to C++11. While C++03 had blanket requirements (e.g. copy constructibility and assignability for vector), C++11 defines fine-g

Answer 1

Even though we already have very good answers on this, I decided to contribute with a more practical answer to show what can and what cannot be done.

So this doesn't work:

vector vec; 

Just read the other answers to understand why. And, as you may have guessed, this won't work either:

vector> vec;

T is no longer const, but vector is holding shared_ptrs, not Ts.

On the other hand, this does work:

vector vec;
vector vec;  // the same as above

But in this case, const is the object being pointed to, not the pointer itself (which is what the vector stores). This would be equivalent to:

vector> vec;

Which is fine.

But if we put const at the end of the expression, it now turns the pointer into a const, so the following won't compile:

vector vec;

A bit confusing, I agree, but you get used to it.