Comparing default-constructed iterators with operator==

Question

Does the C++ Standard say I should be able to compare two default-constructed STL iterators for equality? Are default-constructed iterators equality-comparable?

I w

Answer 1

OK, I'll take a stab. The C++ Standard, Section 24.1/5:

Iterators can also have singular values that are not associated with any container. [Example: After the declaration of an uninitialized pointer x (as with int* x;), x must always be assumed to have a singular value of a pointer. ] Results of most expressions are undefined for singular values; the only excep- tion is an assignment of a non-singular value to an iterator that holds a singular value.

So, no, they can't be compared.