From 40207762a82f9d6fde9a9ac529ea3a170dac1a91 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Fran=C3=A7ois=20Dumont?= <fdumont@gcc.gnu.org>
Date: Tue, 29 Nov 2011 07:45:58 +0000
Subject: [PATCH] hashtable.h (_Hashtable<>::_M_rehash): Remove code useless
 now that the hashtable implementation put the hash code in...
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

2011-11-29  François Dumont <fdumont@gcc.gnu.org>

	* include/bits/hashtable.h (_Hashtable<>::_M_rehash): Remove code
	useless now that the hashtable implementation put the hash code in
	cache if the hash functor throws.
	* testsuite/23_containers/unordered_set/erase/1.cc: Enhance test by
	checking also distance between begin and end iterators to validate
	underlying data model.
	* testsuite/23_containers/unordered_multiset/erase/1.cc: Likewise.
	* testsuire/23_containers/unordered_map/erase/1.cc: Likewise.
	* testsuite/23_containers/unordered_multimap/erase/1.cc: Likewise.
	* testsuite/23_containers/unordered_multiset/erase/2.cc: New.
	* testsuite/23_containers/unordered_multimap/erase/2.cc: New.

From-SVN: r181799
---
 libstdc++-v3/ChangeLog                        | 14 +++
 libstdc++-v3/include/bits/hashtable.h         | 44 ++-------
 .../23_containers/unordered_map/erase/1.cc    | 38 +++++++-
 .../unordered_multimap/erase/1.cc             | 36 ++++++++
 .../unordered_multimap/erase/2.cc             | 90 +++++++++++++++++++
 .../unordered_multiset/erase/1.cc             | 12 +++
 .../unordered_multiset/erase/2.cc             | 89 ++++++++++++++++++
 .../23_containers/unordered_set/erase/1.cc    | 36 ++++++++
 8 files changed, 319 insertions(+), 40 deletions(-)
 create mode 100644 libstdc++-v3/testsuite/23_containers/unordered_multimap/erase/2.cc
 create mode 100644 libstdc++-v3/testsuite/23_containers/unordered_multiset/erase/2.cc

diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index 48c3db230390..4be8353ab44e 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,17 @@
+2011-11-29  François Dumont <fdumont@gcc.gnu.org>
+
+	* include/bits/hashtable.h (_Hashtable<>::_M_rehash): Remove code
+	useless now that the hashtable implementation put the hash code in
+	cache if the hash functor throws.
+	* testsuite/23_containers/unordered_set/erase/1.cc: Enhance test by
+	checking also distance between begin and end iterators to validate
+	underlying data model.
+	* testsuite/23_containers/unordered_multiset/erase/1.cc: Likewise.
+	* testsuire/23_containers/unordered_map/erase/1.cc: Likewise.
+	* testsuite/23_containers/unordered_multimap/erase/1.cc: Likewise.
+	* testsuite/23_containers/unordered_multiset/erase/2.cc: New.
+	* testsuite/23_containers/unordered_multimap/erase/2.cc: New.
+
 2011-11-28  Andrew MacLeod  <amacleod@redhat.com>
 
 	* include/bits/atomic_base.h (ATOMIC_*_LOCK_FREE): Use new cpp
diff --git a/libstdc++-v3/include/bits/hashtable.h b/libstdc++-v3/include/bits/hashtable.h
index dfa91f7cc8cf..712b1df91c28 100644
--- a/libstdc++-v3/include/bits/hashtable.h
+++ b/libstdc++-v3/include/bits/hashtable.h
@@ -233,11 +233,6 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       void
       _M_deallocate_node(_Node* __n);
 
-      // Deallocate all nodes contained in the bucket array, buckets' nodes
-      // are not linked to each other
-      void
-      _M_deallocate_nodes(_Bucket*, size_type);
-
       // Deallocate the linked list of nodes pointed to by __n
       void
       _M_deallocate_nodes(_Node* __n);
@@ -584,19 +579,6 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       _M_node_allocator.deallocate(__n, 1);
     }
 
-  template<typename _Key, typename _Value,
-	   typename _Allocator, typename _ExtractKey, typename _Equal,
-	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
-	   bool __chc, bool __cit, bool __uk>
-    void
-    _Hashtable<_Key, _Value, _Allocator, _ExtractKey, _Equal,
-	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
-    _M_deallocate_nodes(_Bucket* __buckets, size_type __n)
-    {
-      for (size_type __i = 0; __i != __n; ++__i)
-	_M_deallocate_nodes(__buckets[__i]);
-    }
-
   template<typename _Key, typename _Value,
 	   typename _Allocator, typename _ExtractKey, typename _Equal,
 	   typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
@@ -1542,11 +1524,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 	       _H1, _H2, _Hash, _RehashPolicy, __chc, __cit, __uk>::
     _M_rehash(size_type __n, const _RehashPolicyState& __state)
     {
-      _Bucket* __new_buckets = nullptr;
-      _Node* __p = _M_buckets[_M_begin_bucket_index];
       __try
 	{
-	  __new_buckets = _M_allocate_buckets(__n);
+	  _Bucket* __new_buckets = _M_allocate_buckets(__n);
+	  _Node* __p = _M_buckets[_M_begin_bucket_index];
 	  // First loop to store each node in its new bucket
 	  while (__p)
 	    {
@@ -1591,24 +1572,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 	}
       __catch(...)
 	{
-	  if (__new_buckets)
-	    {
-	      // A failure here means that a hash function threw an exception.
-	      // We can't restore the previous state without calling the hash
-	      // function again, so the only sensible recovery is to delete
-	      // everything.
-	      _M_deallocate_nodes(__new_buckets, __n);
-	      _M_deallocate_buckets(__new_buckets, __n);
-	      _M_deallocate_nodes(__p);
-	      __builtin_memset(_M_buckets, 0, sizeof(_Bucket) * _M_bucket_count);
-	      _M_element_count = 0;
-	      _M_begin_bucket_index = _M_bucket_count;
-	      _M_rehash_policy._M_reset(_RehashPolicyState());
-	    }
-	  else
-	    // A failure here means that buckets allocation failed.  We only
-	    // have to restore hash policy previous state.
-	    _M_rehash_policy._M_reset(__state);
+	  // A failure here means that buckets allocation failed.  We only
+	  // have to restore hash policy previous state.
+	  _M_rehash_policy._M_reset(__state);
 	  __throw_exception_again;
 	}
     }
diff --git a/libstdc++-v3/testsuite/23_containers/unordered_map/erase/1.cc b/libstdc++-v3/testsuite/23_containers/unordered_map/erase/1.cc
index f9b74e08c8d1..9863ef792bae 100644
--- a/libstdc++-v3/testsuite/23_containers/unordered_map/erase/1.cc
+++ b/libstdc++-v3/testsuite/23_containers/unordered_map/erase/1.cc
@@ -23,6 +23,18 @@
 #include <string>
 #include <testsuite_hooks.h>
 
+namespace
+{
+  std::size_t
+  get_nb_bucket_elems(const std::unordered_map<std::string, int>& us)
+  {
+    std::size_t nb = 0;
+    for (std::size_t b = 0; b != us.bucket_count(); ++b)
+      nb += us.bucket_size(b);
+    return nb;
+  }
+}
+
 void test01()
 {
   bool test __attribute__((unused)) = true;
@@ -33,7 +45,7 @@ void test01()
   typedef Map::value_type     value_type;
 
   Map m1;
-
+ 
   m1.insert(value_type("because to why", 1));
   m1.insert(value_type("the stockholm syndrome", 2));
   m1.insert(value_type("a cereous night", 3));
@@ -45,14 +57,20 @@ void test01()
   m1.insert(value_type("belonging (no longer mix)", 9));
   m1.insert(value_type("one line behind", 10));
   VERIFY( m1.size() == 10 );
+  VERIFY( get_nb_bucket_elems(m1) == m1.size() );
+  VERIFY( distance(m1.begin(), m1.end()) == m1.size() );
 
   VERIFY( m1.erase("eeilo") == 1 );
   VERIFY( m1.size() == 9 );
+  VERIFY( get_nb_bucket_elems(m1) == m1.size() );
+  VERIFY( distance(m1.begin(), m1.end()) == m1.size() );
   iterator it1 = m1.find("eeilo");
   VERIFY( it1 == m1.end() );
 
   VERIFY( m1.erase("tillsammans") == 1 );
   VERIFY( m1.size() == 8 );
+  VERIFY( get_nb_bucket_elems(m1) == m1.size() );
+  VERIFY( distance(m1.begin(), m1.end()) == m1.size() );
   iterator it2 = m1.find("tillsammans");
   VERIFY( it2 == m1.end() );
 
@@ -61,17 +79,23 @@ void test01()
   VERIFY( it3 != m1.end() );
   VERIFY( m1.erase(it3->first) == 1 );
   VERIFY( m1.size() == 7 );
+  VERIFY( get_nb_bucket_elems(m1) == m1.size() );
+  VERIFY( distance(m1.begin(), m1.end()) == m1.size() );
   it3 = m1.find("belonging (no longer mix)");
   VERIFY( it3 == m1.end() );
 
   VERIFY( !m1.erase("abra") );
   VERIFY( m1.size() == 7 );
+  VERIFY( get_nb_bucket_elems(m1) == m1.size() );
+  VERIFY( distance(m1.begin(), m1.end()) == m1.size() );
 
   VERIFY( !m1.erase("eeilo") );
   VERIFY( m1.size() == 7 );
 
   VERIFY( m1.erase("because to why") == 1 );
   VERIFY( m1.size() == 6 );
+  VERIFY( get_nb_bucket_elems(m1) == m1.size() );
+  VERIFY( distance(m1.begin(), m1.end()) == m1.size() );
   iterator it4 = m1.find("because to why");
   VERIFY( it4 == m1.end() );
 
@@ -87,11 +111,15 @@ void test01()
 
   VERIFY( m1.erase(it5->first) == 1 );
   VERIFY( m1.size() == 5 );
+  VERIFY( get_nb_bucket_elems(m1) == m1.size() );
+  VERIFY( distance(m1.begin(), m1.end()) == m1.size() );
   it5 = m1.find("umbra/penumbra");
   VERIFY( it5 == m1.end() );
 
   VERIFY( m1.erase(it6->first) == 1 );
   VERIFY( m1.size() == 4 );
+  VERIFY( get_nb_bucket_elems(m1) == m1.size() );
+  VERIFY( distance(m1.begin(), m1.end()) == m1.size() );
   it6 = m1.find("one line behind");
   VERIFY( it6 == m1.end() );
 
@@ -103,6 +131,8 @@ void test01()
 
   VERIFY( m1.erase(it8->first) == 1 );
   VERIFY( m1.size() == 3 );
+  VERIFY( get_nb_bucket_elems(m1) == m1.size() );
+  VERIFY( distance(m1.begin(), m1.end()) == m1.size() );
   VERIFY( ++it7 == it9 );
 
   iterator it10 = it9;
@@ -110,15 +140,21 @@ void test01()
   iterator it11 = it10;
 
   VERIFY( m1.erase(it9->first) == 1 );
+  VERIFY( get_nb_bucket_elems(m1) == m1.size() );
+  VERIFY( distance(m1.begin(), m1.end()) == m1.size() );
   VERIFY( m1.size() == 2 );
   VERIFY( ++it10 == m1.end() );
 
   VERIFY( m1.erase(m1.begin()) != m1.end() );  
   VERIFY( m1.size() == 1 );
+  VERIFY( get_nb_bucket_elems(m1) == m1.size() );
+  VERIFY( distance(m1.begin(), m1.end()) == m1.size() );
   VERIFY( m1.begin() == it11 );
 
   VERIFY( m1.erase(m1.begin()->first) == 1 );  
   VERIFY( m1.size() == 0 );
+  VERIFY( get_nb_bucket_elems(m1) == m1.size() );
+  VERIFY( distance(m1.begin(), m1.end()) == m1.size() );
   VERIFY( m1.begin() == m1.end() );
 }
 
diff --git a/libstdc++-v3/testsuite/23_containers/unordered_multimap/erase/1.cc b/libstdc++-v3/testsuite/23_containers/unordered_multimap/erase/1.cc
index 09515726598e..c599cc01a73f 100644
--- a/libstdc++-v3/testsuite/23_containers/unordered_multimap/erase/1.cc
+++ b/libstdc++-v3/testsuite/23_containers/unordered_multimap/erase/1.cc
@@ -23,6 +23,18 @@
 #include <string>
 #include <testsuite_hooks.h>
 
+namespace
+{
+  std::size_t
+  get_nb_bucket_elems(const std::unordered_multimap<std::string, int>& us)
+  {
+    std::size_t nb = 0;
+    for (std::size_t b = 0; b != us.bucket_count(); ++b)
+      nb += us.bucket_size(b);
+    return nb;
+  }
+}
+
 void test01()
 {
   bool test __attribute__((unused)) = true;
@@ -46,14 +58,20 @@ void test01()
   mm1.insert(value_type("one line behind", 10));
   mm1.insert(value_type("because to why", 11));
   VERIFY( mm1.size() == 11 );
+  VERIFY( get_nb_bucket_elems(mm1) == mm1.size() );
+  VERIFY( distance(mm1.begin(), mm1.end()) == mm1.size() );
 
   VERIFY( mm1.erase("eeilo") == 1 );
   VERIFY( mm1.size() == 10 );
+  VERIFY( get_nb_bucket_elems(mm1) == mm1.size() );
+  VERIFY( distance(mm1.begin(), mm1.end()) == mm1.size() );
   iterator it1 = mm1.find("eeilo");
   VERIFY( it1 == mm1.end() );
 
   VERIFY( mm1.erase("tillsammans") == 1 );
   VERIFY( mm1.size() == 9 );
+  VERIFY( get_nb_bucket_elems(mm1) == mm1.size() );
+  VERIFY( distance(mm1.begin(), mm1.end()) == mm1.size() );
   iterator it2 = mm1.find("tillsammans");
   VERIFY( it2 == mm1.end() );
 
@@ -62,17 +80,23 @@ void test01()
   VERIFY( it3 != mm1.end() );
   VERIFY( mm1.erase(it3->first) == 1 );
   VERIFY( mm1.size() == 8 );
+  VERIFY( get_nb_bucket_elems(mm1) == mm1.size() );
+  VERIFY( distance(mm1.begin(), mm1.end()) == mm1.size() );
   it3 = mm1.find("belonging (no longer mix)");
   VERIFY( it3 == mm1.end() );
 
   VERIFY( !mm1.erase("abra") );
   VERIFY( mm1.size() == 8 );
+  VERIFY( get_nb_bucket_elems(mm1) == mm1.size() );
+  VERIFY( distance(mm1.begin(), mm1.end()) == mm1.size() );
 
   VERIFY( !mm1.erase("eeilo") );
   VERIFY( mm1.size() == 8 );
 
   VERIFY( mm1.erase("because to why") == 2 );
   VERIFY( mm1.size() == 6 );
+  VERIFY( get_nb_bucket_elems(mm1) == mm1.size() );
+  VERIFY( distance(mm1.begin(), mm1.end()) == mm1.size() );
   iterator it4 = mm1.find("because to why");
   VERIFY( it4 == mm1.end() );
 
@@ -88,11 +112,15 @@ void test01()
 
   VERIFY( mm1.erase(it5->first) == 1 );
   VERIFY( mm1.size() == 5 );
+  VERIFY( get_nb_bucket_elems(mm1) == mm1.size() );
+  VERIFY( distance(mm1.begin(), mm1.end()) == mm1.size() );
   it5 = mm1.find("umbra/penumbra");
   VERIFY( it5 == mm1.end() );
 
   VERIFY( mm1.erase(it6->first) == 1 );
   VERIFY( mm1.size() == 4 );
+  VERIFY( get_nb_bucket_elems(mm1) == mm1.size() );
+  VERIFY( distance(mm1.begin(), mm1.end()) == mm1.size() );
   it6 = mm1.find("one line behind");
   VERIFY( it6 == mm1.end() );
 
@@ -104,6 +132,8 @@ void test01()
 
   VERIFY( mm1.erase(it8->first) == 1 );
   VERIFY( mm1.size() == 3 );
+  VERIFY( get_nb_bucket_elems(mm1) == mm1.size() );
+  VERIFY( distance(mm1.begin(), mm1.end()) == mm1.size() );
   VERIFY( ++it7 == it9 );
 
   iterator it10 = it9;
@@ -111,15 +141,21 @@ void test01()
   iterator it11 = it10;
 
   VERIFY( mm1.erase(it9->first) == 1 );
+  VERIFY( get_nb_bucket_elems(mm1) == mm1.size() );
+  VERIFY( distance(mm1.begin(), mm1.end()) == mm1.size() );
   VERIFY( mm1.size() == 2 );
   VERIFY( ++it10 == mm1.end() );
 
   VERIFY( mm1.erase(mm1.begin()) != mm1.end() );  
   VERIFY( mm1.size() == 1 );
+  VERIFY( get_nb_bucket_elems(mm1) == mm1.size() );
+  VERIFY( distance(mm1.begin(), mm1.end()) == mm1.size() );
   VERIFY( mm1.begin() == it11 );
 
   VERIFY( mm1.erase(mm1.begin()->first) == 1 );  
   VERIFY( mm1.size() == 0 );
+  VERIFY( get_nb_bucket_elems(mm1) == mm1.size() );
+  VERIFY( distance(mm1.begin(), mm1.end()) == mm1.size() );
   VERIFY( mm1.begin() == mm1.end() );
 }
 
diff --git a/libstdc++-v3/testsuite/23_containers/unordered_multimap/erase/2.cc b/libstdc++-v3/testsuite/23_containers/unordered_multimap/erase/2.cc
new file mode 100644
index 000000000000..df73a85dcc15
--- /dev/null
+++ b/libstdc++-v3/testsuite/23_containers/unordered_multimap/erase/2.cc
@@ -0,0 +1,90 @@
+// { dg-options "-std=gnu++0x" }
+
+// Copyright (C) 2011 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+#include <unordered_map>
+#include <string>
+#include <testsuite_hooks.h>
+
+namespace
+{
+  std::size_t
+  get_nb_bucket_elems(const std::unordered_multimap<std::string, int>& um)
+  {
+    std::size_t nb = 0;
+    for (std::size_t b = 0; b != um.bucket_count(); ++b)
+      nb += um.bucket_size(b);
+    return nb;
+  }
+}
+
+void test01()
+{
+  bool test __attribute__((unused)) = true;
+  
+  typedef std::unordered_multimap<std::string, int> Mmap;
+  typedef Mmap::iterator       iterator;
+  typedef Mmap::const_iterator const_iterator;
+  typedef Mmap::value_type     value_type;
+
+  Mmap mm1;
+  
+  mm1.insert(value_type("foo", 10));
+  mm1.insert(value_type("foo", 11));
+  mm1.insert(value_type("foo", 12));
+  mm1.insert(value_type("foo", 13));
+  mm1.insert(value_type("foo", 14));
+  mm1.insert(value_type("foo", 15));
+  mm1.insert(value_type("bar", 20));
+  mm1.insert(value_type("bar", 21));
+  mm1.insert(value_type("bar", 22));
+  mm1.insert(value_type("bar", 23));
+  mm1.insert(value_type("bar", 24));
+  mm1.insert(value_type("bar", 25));
+  VERIFY( mm1.size() == 12 );
+  VERIFY( get_nb_bucket_elems(mm1) == mm1.size() );
+  VERIFY( distance(mm1.begin(), mm1.end()) == mm1.size() );
+
+  VERIFY( mm1.erase(mm1.begin()) != mm1.end() );
+  VERIFY( mm1.size() == 11 );
+  VERIFY( get_nb_bucket_elems(mm1) == mm1.size() );
+  VERIFY( distance(mm1.begin(), mm1.end()) == mm1.size() );
+
+  auto it = mm1.begin();
+  advance(it, 2);
+  VERIFY( mm1.erase(mm1.begin(), it) != mm1.end() );
+  VERIFY( mm1.size() == 9 );
+  VERIFY( get_nb_bucket_elems(mm1) == mm1.size() );
+  VERIFY( distance(mm1.begin(), mm1.end()) == mm1.size() );
+
+  VERIFY( mm1.erase(mm1.begin()->first) == 3 );
+  VERIFY( mm1.size() == 6 );
+  VERIFY( get_nb_bucket_elems(mm1) == mm1.size() );
+  VERIFY( distance(mm1.begin(), mm1.end()) == mm1.size() );
+
+  VERIFY( mm1.erase(mm1.begin(), mm1.end()) == mm1.end() );
+  VERIFY( mm1.empty() );
+  VERIFY( get_nb_bucket_elems(mm1) == mm1.size() );
+  VERIFY( distance(mm1.begin(), mm1.end()) == mm1.size() );
+}
+
+int main()
+{
+  test01();
+  return 0;
+}
diff --git a/libstdc++-v3/testsuite/23_containers/unordered_multiset/erase/1.cc b/libstdc++-v3/testsuite/23_containers/unordered_multiset/erase/1.cc
index e48e31149e3e..b95c8a38706a 100644
--- a/libstdc++-v3/testsuite/23_containers/unordered_multiset/erase/1.cc
+++ b/libstdc++-v3/testsuite/23_containers/unordered_multiset/erase/1.cc
@@ -58,16 +58,19 @@ void test01()
   ms1.insert("because to why");
   VERIFY( ms1.size() == 11 );
   VERIFY( get_nb_bucket_elems(ms1) == ms1.size() );
+  VERIFY( distance(ms1.begin(), ms1.end()) == ms1.size() );
 
   VERIFY( ms1.erase("eeilo") == 1 );
   VERIFY( ms1.size() == 10 );
   VERIFY( get_nb_bucket_elems(ms1) == ms1.size() );
+  VERIFY( distance(ms1.begin(), ms1.end()) == ms1.size() );
   iterator it1 = ms1.find("eeilo");
   VERIFY( it1 == ms1.end() );
 
   VERIFY( ms1.erase("tillsammans") == 1 );
   VERIFY( ms1.size() == 9 );
   VERIFY( get_nb_bucket_elems(ms1) == ms1.size() );
+  VERIFY( distance(ms1.begin(), ms1.end()) == ms1.size() );
   iterator it2 = ms1.find("tillsammans");
   VERIFY( it2 == ms1.end() );
 
@@ -77,12 +80,14 @@ void test01()
   VERIFY( ms1.erase(*it3) == 1 );
   VERIFY( ms1.size() == 8 );
   VERIFY( get_nb_bucket_elems(ms1) == ms1.size() );
+  VERIFY( distance(ms1.begin(), ms1.end()) == ms1.size() );
   it3 = ms1.find("belonging (no longer mix)");
   VERIFY( it3 == ms1.end() );
 
   VERIFY( !ms1.erase("abra") );
   VERIFY( ms1.size() == 8 );
   VERIFY( get_nb_bucket_elems(ms1) == ms1.size() );
+  VERIFY( distance(ms1.begin(), ms1.end()) == ms1.size() );
 
   VERIFY( !ms1.erase("eeilo") );
   VERIFY( ms1.size() == 8 );
@@ -90,6 +95,7 @@ void test01()
   VERIFY( ms1.erase("because to why") == 2 );
   VERIFY( ms1.size() == 6 );
   VERIFY( get_nb_bucket_elems(ms1) == ms1.size() );
+  VERIFY( distance(ms1.begin(), ms1.end()) == ms1.size() );
   iterator it4 = ms1.find("because to why");
   VERIFY( it4 == ms1.end() );
 
@@ -106,12 +112,14 @@ void test01()
   VERIFY( ms1.erase(*it5) == 1 );
   VERIFY( ms1.size() == 5 );
   VERIFY( get_nb_bucket_elems(ms1) == ms1.size() );
+  VERIFY( distance(ms1.begin(), ms1.end()) == ms1.size() );
   it5 = ms1.find("umbra/penumbra");
   VERIFY( it5 == ms1.end() );
 
   VERIFY( ms1.erase(*it6) == 1 );
   VERIFY( ms1.size() == 4 );
   VERIFY( get_nb_bucket_elems(ms1) == ms1.size() );
+  VERIFY( distance(ms1.begin(), ms1.end()) == ms1.size() );
   it6 = ms1.find("one line behind");
   VERIFY( it6 == ms1.end() );
 
@@ -124,6 +132,7 @@ void test01()
   VERIFY( ms1.erase(*it8) == 1 );
   VERIFY( ms1.size() == 3 );
   VERIFY( get_nb_bucket_elems(ms1) == ms1.size() );
+  VERIFY( distance(ms1.begin(), ms1.end()) == ms1.size() );
   VERIFY( ++it7 == it9 );
 
   iterator it10 = it9;
@@ -132,17 +141,20 @@ void test01()
 
   VERIFY( ms1.erase(*it9) == 1 );
   VERIFY( get_nb_bucket_elems(ms1) == ms1.size() );
+  VERIFY( distance(ms1.begin(), ms1.end()) == ms1.size() );
   VERIFY( ms1.size() == 2 );
   VERIFY( ++it10 == ms1.end() );
 
   VERIFY( ms1.erase(ms1.begin()) != ms1.end() );  
   VERIFY( ms1.size() == 1 );
   VERIFY( get_nb_bucket_elems(ms1) == ms1.size() );
+  VERIFY( distance(ms1.begin(), ms1.end()) == ms1.size() );
   VERIFY( ms1.begin() == it11 );
 
   VERIFY( ms1.erase(*ms1.begin()) == 1 );  
   VERIFY( ms1.size() == 0 );
   VERIFY( get_nb_bucket_elems(ms1) == ms1.size() );
+  VERIFY( distance(ms1.begin(), ms1.end()) == ms1.size() );
   VERIFY( ms1.begin() == ms1.end() );
 }
 
diff --git a/libstdc++-v3/testsuite/23_containers/unordered_multiset/erase/2.cc b/libstdc++-v3/testsuite/23_containers/unordered_multiset/erase/2.cc
new file mode 100644
index 000000000000..ad6cad4a00df
--- /dev/null
+++ b/libstdc++-v3/testsuite/23_containers/unordered_multiset/erase/2.cc
@@ -0,0 +1,89 @@
+// { dg-options "-std=gnu++0x" }
+
+// Copyright (C) 2011 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+#include <unordered_set>
+#include <string>
+#include <testsuite_hooks.h>
+
+namespace
+{
+  std::size_t
+  get_nb_bucket_elems(const std::unordered_multiset<std::string>& us)
+  {
+    std::size_t nb = 0;
+    for (std::size_t b = 0; b != us.bucket_count(); ++b)
+      nb += us.bucket_size(b);
+    return nb;
+  }
+}
+
+void test01()
+{
+  bool test __attribute__((unused)) = true;
+  
+  typedef std::unordered_multiset<std::string> Mset;
+  typedef Mset::iterator       iterator;
+  typedef Mset::const_iterator const_iterator;
+
+  Mset ms1;
+  
+  ms1.insert("foo");
+  ms1.insert("foo");
+  ms1.insert("foo");
+  ms1.insert("foo");
+  ms1.insert("foo");
+  ms1.insert("foo");
+  ms1.insert("bar");
+  ms1.insert("bar");
+  ms1.insert("bar");
+  ms1.insert("bar");
+  ms1.insert("bar");
+  ms1.insert("bar");
+  VERIFY( ms1.size() == 12 );
+  VERIFY( get_nb_bucket_elems(ms1) == ms1.size() );
+  VERIFY( distance(ms1.begin(), ms1.end()) == ms1.size() );
+
+  VERIFY( ms1.erase(ms1.begin()) != ms1.end() );
+  VERIFY( ms1.size() == 11 );
+  VERIFY( get_nb_bucket_elems(ms1) == ms1.size() );
+  VERIFY( distance(ms1.begin(), ms1.end()) == ms1.size() );
+
+  auto it = ms1.begin();
+  advance(it, 2);
+  VERIFY( ms1.erase(ms1.begin(), it) != ms1.end() );
+  VERIFY( ms1.size() == 9 );
+  VERIFY( get_nb_bucket_elems(ms1) == ms1.size() );
+  VERIFY( distance(ms1.begin(), ms1.end()) == ms1.size() );
+
+  VERIFY( ms1.erase(*(ms1.begin())) == 3 );
+  VERIFY( ms1.size() == 6 );
+  VERIFY( get_nb_bucket_elems(ms1) == ms1.size() );
+  VERIFY( distance(ms1.begin(), ms1.end()) == ms1.size() );
+
+  VERIFY( ms1.erase(ms1.begin(), ms1.end()) == ms1.end() );
+  VERIFY( ms1.empty() );
+  VERIFY( get_nb_bucket_elems(ms1) == ms1.size() );
+  VERIFY( distance(ms1.begin(), ms1.end()) == ms1.size() );
+}
+
+int main()
+{
+  test01();
+  return 0;
+}
diff --git a/libstdc++-v3/testsuite/23_containers/unordered_set/erase/1.cc b/libstdc++-v3/testsuite/23_containers/unordered_set/erase/1.cc
index 8f59773d8023..cdefef2afc1d 100644
--- a/libstdc++-v3/testsuite/23_containers/unordered_set/erase/1.cc
+++ b/libstdc++-v3/testsuite/23_containers/unordered_set/erase/1.cc
@@ -23,6 +23,18 @@
 #include <string>
 #include <testsuite_hooks.h>
 
+namespace
+{
+  std::size_t
+  get_nb_bucket_elems(const std::unordered_set<std::string>& us)
+  {
+    std::size_t nb = 0;
+    for (std::size_t b = 0; b != us.bucket_count(); ++b)
+      nb += us.bucket_size(b);
+    return nb;
+  }
+}
+
 void test01()
 {
   bool test __attribute__((unused)) = true;
@@ -44,14 +56,20 @@ void test01()
   s1.insert("belonging (no longer mix)");
   s1.insert("one line behind");
   VERIFY( s1.size() == 10 );
+  VERIFY( get_nb_bucket_elems(s1) == s1.size() );
+  VERIFY( distance(s1.begin(), s1.end()) == s1.size() );
 
   VERIFY( s1.erase("eeilo") == 1 );
   VERIFY( s1.size() == 9 );
+  VERIFY( get_nb_bucket_elems(s1) == s1.size() );
+  VERIFY( distance(s1.begin(), s1.end()) == s1.size() );
   iterator it1 = s1.find("eeilo");
   VERIFY( it1 == s1.end() );
 
   VERIFY( s1.erase("tillsammans") == 1 );
   VERIFY( s1.size() == 8 );
+  VERIFY( get_nb_bucket_elems(s1) == s1.size() );
+  VERIFY( distance(s1.begin(), s1.end()) == s1.size() );
   iterator it2 = s1.find("tillsammans");
   VERIFY( it2 == s1.end() );
 
@@ -60,17 +78,23 @@ void test01()
   VERIFY( it3 != s1.end() );
   VERIFY( s1.erase(*it3) == 1 );
   VERIFY( s1.size() == 7 );
+  VERIFY( get_nb_bucket_elems(s1) == s1.size() );
+  VERIFY( distance(s1.begin(), s1.end()) == s1.size() );
   it3 = s1.find("belonging (no longer mix)");
   VERIFY( it3 == s1.end() );
 
   VERIFY( !s1.erase("abra") );
   VERIFY( s1.size() == 7 );
+  VERIFY( get_nb_bucket_elems(s1) == s1.size() );
+  VERIFY( distance(s1.begin(), s1.end()) == s1.size() );
 
   VERIFY( !s1.erase("eeilo") );
   VERIFY( s1.size() == 7 );
 
   VERIFY( s1.erase("because to why") == 1 );
   VERIFY( s1.size() == 6 );
+  VERIFY( get_nb_bucket_elems(s1) == s1.size() );
+  VERIFY( distance(s1.begin(), s1.end()) == s1.size() );
   iterator it4 = s1.find("because to why");
   VERIFY( it4 == s1.end() );
 
@@ -86,11 +110,15 @@ void test01()
 
   VERIFY( s1.erase(*it5) == 1 );
   VERIFY( s1.size() == 5 );
+  VERIFY( get_nb_bucket_elems(s1) == s1.size() );
+  VERIFY( distance(s1.begin(), s1.end()) == s1.size() );
   it5 = s1.find("umbra/penumbra");
   VERIFY( it5 == s1.end() );
 
   VERIFY( s1.erase(*it6) == 1 );
   VERIFY( s1.size() == 4 );
+  VERIFY( get_nb_bucket_elems(s1) == s1.size() );
+  VERIFY( distance(s1.begin(), s1.end()) == s1.size() );
   it6 = s1.find("one line behind");
   VERIFY( it6 == s1.end() );
 
@@ -102,6 +130,8 @@ void test01()
 
   VERIFY( s1.erase(*it8) == 1 );
   VERIFY( s1.size() == 3 );
+  VERIFY( get_nb_bucket_elems(s1) == s1.size() );
+  VERIFY( distance(s1.begin(), s1.end()) == s1.size() );
   VERIFY( ++it7 == it9 );
 
   iterator it10 = it9;
@@ -109,15 +139,21 @@ void test01()
   iterator it11 = it10;
 
   VERIFY( s1.erase(*it9) == 1 );
+  VERIFY( get_nb_bucket_elems(s1) == s1.size() );
+  VERIFY( distance(s1.begin(), s1.end()) == s1.size() );
   VERIFY( s1.size() == 2 );
   VERIFY( ++it10 == s1.end() );
 
   VERIFY( s1.erase(s1.begin()) != s1.end() );  
   VERIFY( s1.size() == 1 );
+  VERIFY( get_nb_bucket_elems(s1) == s1.size() );
+  VERIFY( distance(s1.begin(), s1.end()) == s1.size() );
   VERIFY( s1.begin() == it11 );
 
   VERIFY( s1.erase(*s1.begin()) == 1 );  
   VERIFY( s1.size() == 0 );
+  VERIFY( get_nb_bucket_elems(s1) == s1.size() );
+  VERIFY( distance(s1.begin(), s1.end()) == s1.size() );
   VERIFY( s1.begin() == s1.end() );
 }
 
-- 
GitLab