std::pair<reference,reference>

[Theodore Papadopoulo]

I wonder whether it would be possible to add some specializations of
pair for it to work even one of its template arguments is a reference.
Below is the specialization example for the case  when the two
parameters are references. Obviously, DR 106 (if/when
adopted/implemented) is a better fix, but in the meantime, maybe a awful
trick like this one could be considered as a quality of
implementation....

If acceptable, I would be glad to implement and test it.

  template<class _T1, class _T2>
    struct pair<_T1&, _T2&>
    {
      typedef _T1 first_type;    ///<  @c first_type is the first bound
type
      typedef _T2 second_type;   ///<  @c second_type is the second
bound type

      _T1& first;                 ///< @c first is a copy of the first
object
      _T2& second;                ///< @c second is a copy of the second
object

      // _GLIBCXX_RESOLVE_LIB_DEFECTS
      // 265.  std::pair::pair() effects overly restrictive
      /** The default constructor creates @c first and @c second using
their
       *  respective default constructors.  */
      pair()
      : first(), second() { }

      /** Two objects may be passed to a @c pair constructor to be
copied.  */
      pair(const _T1& __a, const _T2& __b)
      : first(__a), second(__b) { }

      /** There is also a templated copy ctor for the @c pair class
itself.  */
      template<class _U1, class _U2>
        pair(const pair<_U1, _U2>& __p)
	: first(__p.first), second(__p.second) { }
    };