Defined in header <memory>        template< class ForwardIt, class Size, class T >
void uninitialized_fill_n( ForwardIt first, Size count, const T& value );     (until C++11)   template< class ForwardIt, class Size, class T >
ForwardIt uninitialized_fill_n( ForwardIt first, Size count, const T& value );     (since C++11)  
Copies the given value value to the first count elements in an uninitialized memory area beginning at first as if by.
for (; n--; ++first)
  ::new