[patch] fix libstdc++/56278

[Jonathan Wakely]

        PR libstdc++/56278
        * include/bits/hashtable_policy.h (_Hash_code_base): Make default
        constructor public.
        * testsuite/23_containers/unordered_set/56278.cc: New.

Tested x86_64-linux, committed to trunk.

commit b893384109ddb4dfc1afac24dc6b2c56557f2fa8
Author: Jonathan Wakely <jwakely....@gmail.com>
Date:   Sun Feb 10 22:08:34 2013 +0000

        PR libstdc++/56278
        * include/bits/hashtable_policy.h (_Hash_code_base): Make default
        constructor public.
        * testsuite/23_containers/unordered_set/56278.cc: New.

diff --git a/libstdc++-v3/include/bits/hashtable_policy.h 
b/libstdc++-v3/include/bits/hashtable_policy.h
index f4d8dc0..a88b32e 100644
--- a/libstdc++-v3/include/bits/hashtable_policy.h
+++ b/libstdc++-v3/include/bits/hashtable_policy.h
@@ -918,13 +918,15 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       using __ebo_extract_key = _Hashtable_ebo_helper<0, _ExtractKey>;
       using __ebo_hash = _Hashtable_ebo_helper<1, _Hash>;
 
+    public:
+      // We need the default constructor for the local iterators.
+      _Hash_code_base() = default;
+
     protected:
       typedef void*                                    __hash_code;
       typedef _Hash_node<_Value, false>                        __node_type;
 
-      // We need the default constructor for the local iterators.
-      _Hash_code_base() = default;
-
+    protected:
       _Hash_code_base(const _ExtractKey& __ex, const _H1&, const _H2&,
                      const _Hash& __h)
       : __ebo_extract_key(__ex), __ebo_hash(__h) { }
@@ -956,7 +958,6 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
        std::swap(_M_ranged_hash(), __x._M_ranged_hash());
       }
 
-    protected:
       const _ExtractKey&
       _M_extract() const { return __ebo_extract_key::_S_cget(*this); }
 
@@ -1003,13 +1004,13 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       hash_function() const
       { return _M_h1(); }
 
+      // We need the default constructor for the local iterators.
+      _Hash_code_base() = default;
+
     protected:
       typedef std::size_t                              __hash_code;
       typedef _Hash_node<_Value, false>                        __node_type;
 
-      // We need the default constructor for the local iterators.
-      _Hash_code_base() = default;
-
       _Hash_code_base(const _ExtractKey& __ex,
                      const _H1& __h1, const _H2& __h2,
                      const _Default_ranged_hash&)
diff --git a/libstdc++-v3/testsuite/23_containers/unordered_set/56278.cc 
b/libstdc++-v3/testsuite/23_containers/unordered_set/56278.cc
new file mode 100644
index 0000000..c73a524
--- /dev/null
+++ b/libstdc++-v3/testsuite/23_containers/unordered_set/56278.cc
@@ -0,0 +1,30 @@
+// { dg-options "-std=gnu++0x" }
+// { dg-do compile }
+
+// Copyright (C) 2013 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/>.
+
+// libstdc++/56278
+
+#include <unordered_set>
+
+struct hash : std::hash<int>
+{
+  hash() { }
+};
+
+std::unordered_set<int, hash>::local_iterator i;