20 General utilities library [utilities]

20.6.12.4 uninitialized_fill_n [uninitialized.fill.n]

template <class ForwardIterator, class Size, class T> ForwardIterator uninitialized_fill_n(ForwardIterator first, Size n, const T& x);

for (; n--; ++first)
  ::new (static_cast<void*>(&*first))
    typename iterator_traits<ForwardIterator>::value_type(x);
return first;