template<class InputIterator, class RandomAccessIterator>
RandomAccessIterator
partial_sort_copy(InputIterator first, InputIterator last,
RandomAccessIterator result_first,
RandomAccessIterator result_last);
template<class InputIterator, class RandomAccessIterator,
class Compare>
RandomAccessIterator
partial_sort_copy(InputIterator first, InputIterator last,
RandomAccessIterator result_first,
RandomAccessIterator result_last,
Compare comp);
Effects: Places the first min(last - first, result_last - result_first) sorted elements into the range [result_first,result_first + min(last - first, result_last - result_first)).
Returns: The smaller of: result_last or result_first + (last - first).
Requires: RandomAccessIterator shall satisfy the requirements of ValueSwappable ([swappable.requirements]). The type of *result_first shall satisfy the requirements of MoveConstructible (Table [moveconstructible]) and of MoveAssignable (Table [moveassignable]).
Complexity: Approximately (last - first) * log(min(last - first, result_last - result_first)) comparisons.