Proposed Text for minmax (N1840)

Explanation

The LWG would like to accept N1840 into the C++0X working draft with one chanage:

• Remove reference_wrapper as it is no longer needed due to CWG issue 106 (references to references).

Proposed Wording

In the header <algorithm> synopsis, add:

// 25.3.7, minimum and maximum:
// [ ... min, max, followed by]
    template <class T> 
      pair<const T&, const T&>
        minmax(const T& a, const T& b); 
    template <class T, class Compare>
      pair<const T&, const T&>
        minmax(const T& a, const T& b, Compare comp);
// [ ... min_element, and max_element]

In section 25.3.7, add:

template <class T> 
  pair<const T&, const T&>
    minmax(const T& a, const T& b); 
template <class T, class Compare>
  pair<const T&, const T&>
    minmax(const T& a, const T& b, Compare comp);

-7- Requires:Type T is LessThanComparable (20.1.2).

-8- Returns: pair<const T&, const T&>(b, a) if b is smaller than a, and pair<const T&, const T&>(a, b) otherwise.

-9- Remarks: Returns pair<const T&, const T&>(a, b) if a and b are equivalent.

-10- Complexity: Exactly one comparison.

In the header <algorithm> synopsis, add (and by the way, the comment heading 25.3.8 is missing in the synopsis even in the 2003 revision):

// 25.3.7, minimum and maximum:
// [... min_element, and max_element, followed by:]
template <class ForwardIterator>
  pair<ForwardIterator, ForwardIterator>
    minmax_element(ForwardIterator first, ForwardIterator last);
template <class ForwardIterator, class Compare>
  pair<ForwardIterator, ForwardIterator>
    minmax_element(ForwardIterator first, ForwardIterator last, Compare comp);

// 25.3.8, lexicographical comparisons:
// [... lexicographical_compare, etc.]

At the end of section 25.3.7, add:

template <class ForwardIterator>
  pair<ForwardIterator, ForwardIterator>
    minmax_element(ForwardIterator first, ForwardIterator last);
template <class ForwardIterator, class Compare>
  pair<ForwardIterator, ForwardIterator>
    minmax_element(ForwardIterator first, ForwardIterator last, Compare comp);

-15- Returns: std::make_pair(m, M) where m is the std::min_element and M the std::max_element of the input range [first, last) for the corresponding comparisons.

-16- Complexity: At most max(2*(last-first)-2, 0) applications of the corresponding comparisons.