template<class ForwardIterator>
void uninitialized_default_construct(ForwardIterator first, ForwardIterator last);
for (; first != last; ++first) ::new (static_cast<void*>(addressof(*first))) typename iterator_traits<ForwardIterator>::value_type;
template<class ForwardIterator, class Size>
ForwardIterator uninitialized_default_construct_n(ForwardIterator first, Size n);