Can pop_back() ever reduce the capacity of a vector? (C++)

Question

According to the C++ standard, is std::vector<T>::pop_back() ever allowed to reduce the capacity of the vector?

I am asking because I would like to have a guarantee, that the following code will not throw an out of memory exception:

my_vec.pop_back();
if (...)
    my_vec.push_back(...);

Assume that my_vec is an std::vector<int>.

I guess there are three possibilities:

1. Yes, this can happen according to both C++03 and C++11.

2. No, C++11 prohibits this (but C++03 does not).

3. No, both C++03 and C++11 prohibits this.

Yes, my question is related to Does std::vector.pop_back() change vector's capacity?, but my question is specifically about what the standard guarantees.

Note also that the accepted answer in Does std::vector.pop_back() change vector's capacity? is mostly about how to reduce the capacity of a vector, not about when it is guaranteed not to happen, and offers no evidence for its claim about pop_back().

Answer 1

According to http://en.cppreference.com/w/cpp/container/vector/pop_back

No iterators or references except for back() and end() are invalidated.

Therefore it may not reallocate. There is no C++11 tag on that page, which implies this is also true in 03. I will dig up the section references and edit them in for completeness.

Edit: Even better: From C++03: [lib.container.requirements] (23.1), paragraph 10:

no erase(), pop_back() or pop_front() function throws an exception.

Same wording at 23.2.1/10 in N3337 (~C++11).