Hi

     libstdc++: [_GLIBCXX_DEBUG] Implement unordered container merge

     The _GLIBCXX_DEBUG unordered containers need a dedicated merge 
implementation
     so that any existing iterator on the transfered nodes is properly 
invalidated.

     Add typedef/using declaration for everything used as-is from normal 
implementation.

     libstdc++-v3/ChangeLog:

             * include/debug/safe_container.h (_Safe_container<>): Make 
all methods
             protected.
             * include/debug/safe_unordered_container.h
             (_Safe_unordered_container<>::_M_invalide_all): Make public.
             (_Safe_unordered_container<>::_M_invalide_if): Likewise.
(_Safe_unordered_container<>::_M_invalide_local_if): Likewise.
             * include/debug/unordered_map
             (unordered_map<>::mapped_type, pointer, const_pointer): New 
typedef.
             (unordered_map<>::reference, const_reference, 
difference_type): New typedef.
             (unordered_map<>::get_allocator, empty, size, max_size): 
Add usings.
             (unordered_map<>::bucket_count, max_bucket_count, bucket): 
Add usings.
             (unordered_map<>::hash_function, key_equal, count, 
contains): Add usings.
             (unordered_map<>::operator[], at, rehash, reserve): Add usings.
             (unordered_map<>::merge): New.
             (unordered_multimap<>::mapped_type, pointer, 
const_pointer): New typedef.
             (unordered_multimap<>::reference, const_reference, 
difference_type): New typedef.
             (unordered_multimap<>::get_allocator, empty, size, 
max_size): Add usings.
             (unordered_multimap<>::bucket_count, max_bucket_count, 
bucket): Add usings.
             (unordered_multimap<>::hash_function, key_equal, count, 
contains): Add usings.
             (unordered_multimap<>::rehash, reserve): Add usings.
             (unordered_multimap<>::merge): New.
             * include/debug/unordered_set
             (unordered_set<>::mapped_type, pointer, const_pointer): New 
typedef.
             (unordered_set<>::reference, const_reference, 
difference_type): New typedef.
             (unordered_set<>::get_allocator, empty, size, max_size): 
Add usings.
             (unordered_set<>::bucket_count, max_bucket_count, bucket): 
Add usings.
             (unordered_set<>::hash_function, key_equal, count, 
contains): Add usings.
             (unordered_set<>::rehash, reserve): Add usings.
             (unordered_set<>::merge): New.
             (unordered_multiset<>::mapped_type, pointer, 
const_pointer): New typedef.
             (unordered_multiset<>::reference, const_reference, 
difference_type): New typedef.
             (unordered_multiset<>::get_allocator, empty, size, 
max_size): Add usings.
             (unordered_multiset<>::bucket_count, max_bucket_count, 
bucket): Add usings.
             (unordered_multiset<>::hash_function, key_equal, count, 
contains): Add usings.
             (unordered_multiset<>::rehash, reserve): Add usings.
             (unordered_multiset<>::merge): New.
             * 
testsuite/23_containers/unordered_map/debug/merge1_neg.cc: New test.
             * 
testsuite/23_containers/unordered_map/debug/merge2_neg.cc: New test.
             * 
testsuite/23_containers/unordered_map/debug/merge3_neg.cc: New test.
             * 
testsuite/23_containers/unordered_map/debug/merge4_neg.cc: New test.
             * 
testsuite/23_containers/unordered_multimap/debug/merge1_neg.cc: New test.
             * 
testsuite/23_containers/unordered_multimap/debug/merge2_neg.cc: New test.
             * 
testsuite/23_containers/unordered_multimap/debug/merge3_neg.cc: New test.
             * 
testsuite/23_containers/unordered_multimap/debug/merge4_neg.cc: New test.
             * 
testsuite/23_containers/unordered_multiset/debug/merge1_neg.cc: New test.
             * 
testsuite/23_containers/unordered_multiset/debug/merge2_neg.cc: New test.
             * 
testsuite/23_containers/unordered_multiset/debug/merge3_neg.cc: New test.
             * 
testsuite/23_containers/unordered_multiset/debug/merge4_neg.cc: New test.
             * 
testsuite/23_containers/unordered_set/debug/merge1_neg.cc: New test.
             * 
testsuite/23_containers/unordered_set/debug/merge2_neg.cc: New test.
             * 
testsuite/23_containers/unordered_set/debug/merge3_neg.cc: New test.
             * 
testsuite/23_containers/unordered_set/debug/merge4_neg.cc: New test.
             * testsuite/util/testsuite_abi.h: [_GLIBCXX_DEBUG] Use 
normal unordered container implementation.

Tested under Linux x86_64.

Ok to commit ?

François