https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86963
--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> --- Author: redi Date: Fri Aug 17 17:52:49 2018 New Revision: 263625 URL: https://gcc.gnu.org/viewcvs?rev=263625&root=gcc&view=rev Log: PR libstdc++/86963 Implement LWG 2729 constraints on tuple assignment PR libstdc++/86963 * include/std/tuple (__tuple_base): New class template with deleted copy assignment operator. (tuple, tuple<_T1, _T2>): Derive from __tuple_base<tuple> so that implicit copy/move assignment operator will be deleted/suppressed. (tuple::__assignable, tuple<_T1, _T2>::__assignable): New helper functions for SFINAE constraints on assignment operators. (tuple::__nothrow_assignable, tuple<_T1, _T2>::__nothrow_assignable): New helper functions for exception specifications. (tuple::operator=(const tuple&), tuple::operator=(tuple&&)) (tuple<_T1, _T2>::operator=(const tuple&)) (tuple<_T1, _T2>::operator=(tuple&&)): Change parameter types to __nonesuch_no_braces when the operator should be defined implicitly. Use __nothrow_assignable for exception specifications. (tuple::operator=(const tuple<_UElements...>&)) (tuple::operator=(tuple<_UElements...>&&)) (tuple<_T1, _T2>::operator=(const tuple<_U1, _U2>&)) (tuple<_T1, _T2>::operator=(tuple<_U1, _U2>&&)) (tuple<_T1, _T2>::operator=(const pair<_U1, _U2>&)) (tuple<_T1, _T2>::operator=(pair<_U1, _U2>&&)): Constrain using __assignable and use __nothrow_assignable for exception specifications. * python/libstdcxx/v6/printers.py (is_specialization_of): Accept gdb.Type as first argument, instead of a string. (StdTuplePrinter._iterator._is_nonempty_tuple): New method to check tuple for expected structure. (StdTuplePrinter._iterator.__init__): Use _is_nonempty_tuple. * testsuite/20_util/tuple/dr2729.cc: New test. * testsuite/20_util/tuple/element_access/get_neg.cc: Change dg-error to dg-prune-output. Added: trunk/libstdc++-v3/testsuite/20_util/tuple/dr2729.cc Modified: trunk/libstdc++-v3/ChangeLog trunk/libstdc++-v3/include/std/tuple trunk/libstdc++-v3/python/libstdcxx/v6/printers.py trunk/libstdc++-v3/testsuite/20_util/tuple/element_access/get_neg.cc