re PR libstdc++/51183 (pair piecewise_construct_t constructor copies)

re PR libstdc++/51183 (pair piecewise_construct_t constructor copies)

2011-12-06  Jonathan Wakely  <jwakely.gcc@gmail.com>
	    Chris Jefferson  <chris@bubblescope.net>

	PR libstdc++/51183
	* include/std/stl_pair.h (pair<>::__cons, pair<>::__do_cons): Remove.
	(pair<>::pair(piecewise_construct_t, tuple<>, tuple<>): Only declare.
	(pair<>::pair(tuple<>&, tuple<>&, _Index_tuple<>, _Index_tuple<>)):
	Declare.
	* include/std/tuple (pair<>::__cons, pair<>::__do_cons): Remove.
	(pair<>::pair(tuple<>&, tuple<>&, _Index_tuple<>, _Index_tuple<>)):
	Define.
	(pair<>::pair(piecewise_construct_t, tuple<>, tuple<>): Define,
	delegating to the latter.
	* testsuite/20_util/pair/piecewise2.cc: New.

Co-Authored-By: Chris Jefferson <chris@bubblescope.net>
From-SVN: r182054