std::vector resize downward

Question

The C++ standard seems to make no statement regarding side-effects on capacity by either resize(n), with n < size(), or clear().

Answer 1

As i checked for gcc (mingw) the only way to free vector capacity is what mattnewport says. Swaping it with other teporary vector. This code makes it for gcc.

template void shrinkContainer(C &container) {
    if (container.size() != container.capacity()) {
        C tmp = container;
        swap(container, tmp);
    }
    //container.size() == container.capacity()
}