re PR libstdc++/41622 ([DR 1245] [c++0x] std::hash<std::string>::operator() copies its argument)

2009-11-19  Paolo Carlini  <paolo.carlini@oracle.com>

	PR libstdc++/41622
	* include/bits/functional_hash.h: Implement inline the various
	std::hash specializations, using, when appropriate, pass by
	const ref too, per DR 1245.
	* include/tr1_impl/functional_hash.h: Remove, move its contents...
	* include/tr1/functional_hash.h: ... here.
	* include/std/functional: Tweak includes.
	* src/hash_c++0x: Rename to...
	* src/compatibility-c++0x.cc: ... this, implementing compatibility
	std::hash<>::operator() specializations.
	* src/hash.cc: Do not mark specializations as throw().
	* src/Makefile.am: Adjust.
	* include/Makefile.am: Likewise.
	* src/Makefile.in: Regenerate.
	* include/Makefile.in: Likewise.
	* testsuite/util/testsuite_api.h: Define a dummy hash for
	NonDefaultConstructible.
	* testsuite/23_containers/unordered_map/requirements/
	explicit_instantiation/2.cc: Use it.
	* testsuite/23_containers/unordered_multimap/requirements/
	explicit_instantiation/2.cc: Likewise.
	* testsuite/23_containers/unordered_set/requirements/
	explicit_instantiation/2.cc: Likewise.
	* testsuite/23_containers/unordered_multiset/requirements/
	explicit_instantiation/2.cc: Likewise.

From-SVN: r154335

16 files changed, 468 insertions, 257 deletions

diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index db8246e..380b6d5 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,31 @@
+2009-11-19  Paolo Carlini  <paolo.carlini@oracle.com>
+
+	PR libstdc++/41622
+	* include/bits/functional_hash.h: Implement inline the various
+	std::hash specializations, using, when appropriate, pass by
+	const ref too, per DR 1245.
+	* include/tr1_impl/functional_hash.h: Remove, move its contents...
+	* include/tr1/functional_hash.h: ... here.
+	* include/std/functional: Tweak includes.
+	* src/hash_c++0x: Rename to...
+	* src/compatibility-c++0x.cc: ... this, implementing compatibility
+	std::hash<>::operator() specializations.
+	* src/hash.cc: Do not mark specializations as throw().
+	* src/Makefile.am: Adjust.
+	* include/Makefile.am: Likewise.
+	* src/Makefile.in: Regenerate.
+	* include/Makefile.in: Likewise.
+	* testsuite/util/testsuite_api.h: Define a dummy hash for
+	NonDefaultConstructible.
+	* testsuite/23_containers/unordered_map/requirements/
+	explicit_instantiation/2.cc: Use it.
+	* testsuite/23_containers/unordered_multimap/requirements/
+	explicit_instantiation/2.cc: Likewise.
+	* testsuite/23_containers/unordered_set/requirements/
+	explicit_instantiation/2.cc: Likewise.
+	* testsuite/23_containers/unordered_multiset/requirements/
+	explicit_instantiation/2.cc: Likewise.
+
 2009-11-19  Johannes Singler  <singler@kit.edu>
 
         * include/parallel/partition.h (__parallel_partition): Correctly
@@ -8,7 +36,7 @@
 2009-11-17  Benjamin Kosnik  <bkoz@redhat.com>
 
 	* include/profile/impl/profiler.h: Remove namespace markup.
-	
+
 2009-11-17  Benjamin Kosnik  <bkoz@redhat.com>
 
 	* include/profile/bitset: Tweak doxygen markup.
diff --git a/libstdc++-v3/include/Makefile.am b/libstdc++-v3/include/Makefile.am
index 1cea8a2..47253e6 100644
--- a/libstdc++-v3/include/Makefile.am
+++ b/libstdc++-v3/include/Makefile.am
@@ -610,7 +610,6 @@ tr1_impl_headers = \
 	${tr1_impl_srcdir}/cwchar \
 	${tr1_impl_srcdir}/cwctype \
 	${tr1_impl_srcdir}/functional \
-	${tr1_impl_srcdir}/functional_hash.h \
 	${tr1_impl_srcdir}/hashtable \
 	${tr1_impl_srcdir}/hashtable_policy.h \
 	${tr1_impl_srcdir}/regex \
diff --git a/libstdc++-v3/include/Makefile.in b/libstdc++-v3/include/Makefile.in
index a1fab9a..71e7489 100644
--- a/libstdc++-v3/include/Makefile.in
+++ b/libstdc++-v3/include/Makefile.in
@@ -850,7 +850,6 @@ tr1_impl_headers = \
 	${tr1_impl_srcdir}/cwchar \
 	${tr1_impl_srcdir}/cwctype \
 	${tr1_impl_srcdir}/functional \
-	${tr1_impl_srcdir}/functional_hash.h \
 	${tr1_impl_srcdir}/hashtable \
 	${tr1_impl_srcdir}/hashtable_policy.h \
 	${tr1_impl_srcdir}/regex \
diff --git a/libstdc++-v3/include/bits/functional_hash.h b/libstdc++-v3/include/bits/functional_hash.h
index 78b0aa3..c045ba0 100644
--- a/libstdc++-v3/include/bits/functional_hash.h
+++ b/libstdc++-v3/include/bits/functional_hash.h
@@ -36,33 +36,232 @@
 # include <c++0x_warning.h>
 #endif
 
-#if defined(_GLIBCXX_INCLUDE_AS_TR1)
-#  error C++0x header cannot be included from TR1 header
+#include <string>
+#include <system_error>
+
+namespace std
+{
+  /// Class template hash.
+  template<typename _Tp>
+    struct hash;
+
+  /// Partial specializations for pointer types.
+  template<typename _Tp>
+    struct hash<_Tp*> : public std::unary_function<_Tp*, size_t>
+    {
+      size_t
+      operator()(_Tp* __p) const
+      { return reinterpret_cast<size_t>(__p); }
+    };
+
+  /// Explicit specializations for integer types.
+#define _Cxx_hashtable_define_trivial_hash(_Tp) 	       \
+  template<>						       \
+    struct hash<_Tp> : public std::unary_function<_Tp, size_t> \
+    {                                                          \
+      size_t                                                   \
+      operator()(_Tp __val) const		               \
+      { return static_cast<size_t>(__val); }		       \
+    };
+
+  _Cxx_hashtable_define_trivial_hash(bool);
+  _Cxx_hashtable_define_trivial_hash(char);
+  _Cxx_hashtable_define_trivial_hash(signed char);
+  _Cxx_hashtable_define_trivial_hash(unsigned char);
+  _Cxx_hashtable_define_trivial_hash(wchar_t);
+#ifdef _GLIBCXX_USE_C99_STDINT_TR1
+  _Cxx_hashtable_define_trivial_hash(char16_t);
+  _Cxx_hashtable_define_trivial_hash(char32_t);
 #endif
+  _Cxx_hashtable_define_trivial_hash(short);
+  _Cxx_hashtable_define_trivial_hash(int);
+  _Cxx_hashtable_define_trivial_hash(long);
+  _Cxx_hashtable_define_trivial_hash(long long);
+  _Cxx_hashtable_define_trivial_hash(unsigned short);
+  _Cxx_hashtable_define_trivial_hash(unsigned int);
+  _Cxx_hashtable_define_trivial_hash(unsigned long);
+  _Cxx_hashtable_define_trivial_hash(unsigned long long);
+
+#undef _Cxx_hashtable_define_trivial_hash
+
+  // Fowler / Noll / Vo (FNV) Hash (type FNV-1a)
+  // (Used by the next specializations of std::tr1::hash.)
+
+  /// Dummy generic implementation (for sizeof(size_t) != 4, 8).
+  template<size_t = sizeof(size_t)>
+    struct _Fnv_hash
+    {
+      static size_t
+      hash(const char* __first, size_t __length)
+      {
+	size_t __result = 0;
+	for (; __length > 0; --__length)
+	  __result = (__result * 131) + *__first++;
+	return __result;
+      }
+    };
+
+  template<>
+    struct _Fnv_hash<4>
+    {
+      static size_t
+      hash(const char* __first, size_t __length)
+      {
+	size_t __result = static_cast<size_t>(2166136261UL);
+	for (; __length > 0; --__length)
+	  {
+	    __result ^= static_cast<size_t>(*__first++);
+	    __result *= static_cast<size_t>(16777619UL);
+	  }
+	return __result;
+      }
+    };
+  
+  template<>
+    struct _Fnv_hash<8>
+    {
+      static size_t
+      hash(const char* __first, size_t __length)
+      {
+	size_t __result =
+	  static_cast<size_t>(14695981039346656037ULL);
+	for (; __length > 0; --__length)
+	  {
+	    __result ^= static_cast<size_t>(*__first++);
+	    __result *= static_cast<size_t>(1099511628211ULL);
+	  }
+	return __result;
+      }
+    };
+
+  /// Explicit specializations for float.
+  template<>
+    struct hash<float>
+    : public std::unary_function<float, size_t>
+    {
+      size_t
+      operator()(float __val) const
+      {
+	size_t __result = 0;
+      
+	// 0 and -0 both hash to zero.
+	if (__val != 0.0f)
+	  __result = _Fnv_hash<>::hash(reinterpret_cast<const char*>(&__val),
+				       sizeof(__val));
+	return __result;
+      }
+    };
+
+  /// Explicit specializations for double.
+  template<>
+    struct hash<double>
+    : public std::unary_function<double, size_t>
+    {
+      size_t
+      operator()(double __val) const
+      {
+	size_t __result = 0;
+
+	// 0 and -0 both hash to zero.
+	if (__val != 0.0)
+	  __result = _Fnv_hash<>::hash(reinterpret_cast<const char*>(&__val),
+				       sizeof(__val));
+	return __result;
+      }
+    };
 
-#if defined(_GLIBCXX_INCLUDE_AS_CXX0X)
-#  include <tr1_impl/functional_hash.h>
-#else
-#  define _GLIBCXX_INCLUDE_AS_CXX0X
-#  define _GLIBCXX_BEGIN_NAMESPACE_TR1
-#  define _GLIBCXX_END_NAMESPACE_TR1
-#  define _GLIBCXX_TR1
-#  include <tr1_impl/functional_hash.h>
-#  undef _GLIBCXX_TR1
-#  undef _GLIBCXX_END_NAMESPACE_TR1
-#  undef _GLIBCXX_BEGIN_NAMESPACE_TR1
-#  undef _GLIBCXX_INCLUDE_AS_CXX0X
+  /// Explicit specializations for long double.
+  template<>
+    struct hash<long double>
+    : public std::unary_function<long double, size_t>
+    {
+      size_t
+      operator()(long double __val) const
+      {
+	size_t __result = 0;
+
+	int __exponent;
+	__val = __builtin_frexpl(__val, &__exponent);
+	__val = __val < 0.0l ? -(__val + 0.5l) : __val;
+
+	const long double __mult =
+	  __gnu_cxx::__numeric_traits<size_t>::__max + 1.0l;
+	__val *= __mult;
+
+	// Try to use all the bits of the mantissa (really necessary only
+	// on 32-bit targets, at least for 80-bit floating point formats).
+	const size_t __hibits = (size_t)__val;
+	__val = (__val - (long double)__hibits) * __mult;
+
+	const size_t __coeff =
+	  __gnu_cxx::__numeric_traits<size_t>::__max / __LDBL_MAX_EXP__;
+
+	__result = __hibits + (size_t)__val + __coeff * __exponent;
+
+	return __result;
+      }
+    };
+
+  template<>
+    struct hash<string>
+    : public std::unary_function<string, size_t>
+    {
+      size_t
+      operator()(const string& __s) const
+      { return _Fnv_hash<>::hash(__s.data(), __s.length()); }
+    };
+
+#ifdef _GLIBCXX_USE_WCHAR_T
+  template<>
+    struct hash<wstring>
+    : public std::unary_function<wstring, size_t>
+    {
+      size_t
+      operator()(const wstring& __s) const
+      {
+	const char* __p = reinterpret_cast<const char*>(__s.data());
+	return _Fnv_hash<>::hash(__p, __s.length() * sizeof(wchar_t));
+      }
+    };
 #endif
 
+#ifdef _GLIBCXX_USE_C99_STDINT_TR1
+  template<>
+    struct hash<u16string>
+    : public std::unary_function<u16string, size_t>
+    {
+      size_t
+      operator()(const u16string& __s) const
+      {
+	const char* __p = reinterpret_cast<const char*>(__s.data());
+	return _Fnv_hash<>::hash(__p, __s.length() * sizeof(char16_t));
+      }
+    };
 
-namespace std
-{
-  struct error_code;
+  template<>
+    struct hash<u32string>
+    : public std::unary_function<u32string, size_t>
+    {
+      size_t
+      operator()(const u32string& __s) const
+      {
+	const char* __p = reinterpret_cast<const char*>(__s.data());
+	return _Fnv_hash<>::hash(__p, __s.length() * sizeof(char32_t));
+      }
+    };
+#endif
 
   template<>
-    _GLIBCXX_PURE size_t
-    hash<error_code>::operator()(error_code) const;
+    struct hash<error_code>
+    : public std::unary_function<error_code, size_t>
+    {
+      size_t
+      operator()(const error_code& __e) const
+      {
+	const char* __p = reinterpret_cast<const char*>(&__e);
+	return _Fnv_hash<>::hash(__p, sizeof(__e));
+      }
+    };
 }
 
 #endif // _FUNCTIONAL_HASH_H
-
diff --git a/libstdc++-v3/include/std/functional b/libstdc++-v3/include/std/functional
index 8f4f42c..e46a27d 100644
--- a/libstdc++-v3/include/std/functional
+++ b/libstdc++-v3/include/std/functional
@@ -57,7 +57,6 @@
 #  include <new>
 #  include <tuple>
 #  include <type_traits>
-#  include <bits/stringfwd.h>
 #  include <bits/functional_hash.h>
 #  include <ext/type_traits.h>
 #  if defined(_GLIBCXX_INCLUDE_AS_CXX0X)
diff --git a/libstdc++-v3/include/tr1/functional_hash.h b/libstdc++-v3/include/tr1/functional_hash.h
index 933ded9..d684930 100644
--- a/libstdc++-v3/include/tr1/functional_hash.h
+++ b/libstdc++-v3/include/tr1/functional_hash.h
@@ -1,6 +1,6 @@
 // TR1 functional_hash.h header -*- C++ -*-
 
-// Copyright (C) 2007, 2009 Free Software Foundation, Inc.
+// Copyright (C) 2007, 2008, 2009 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
@@ -32,22 +32,154 @@
 
 #pragma GCC system_header
 
-#if defined(_GLIBCXX_INCLUDE_AS_CXX0X)
-#  error TR1 header cannot be included from C++0x header
-#endif
+namespace std
+{
+namespace tr1
+{
+  /// Class template hash.
+  // Declaration of default hash functor std::tr1::hash.  The types for
+  // which std::tr1::hash<T> is well-defined is in clause 6.3.3. of the PDTR.
+  template<typename _Tp>
+    struct hash : public std::unary_function<_Tp, size_t>
+    {
+      size_t
+      operator()(_Tp __val) const;
+    };
+
+  /// Partial specializations for pointer types.
+  template<typename _Tp>
+    struct hash<_Tp*> : public std::unary_function<_Tp*, size_t>
+    {
+      size_t
+      operator()(_Tp* __p) const
+      { return reinterpret_cast<size_t>(__p); }
+    };
+
+  /// Explicit specializations for integer types.
+#define _TR1_hashtable_define_trivial_hash(_Tp) 	\
+  template<>						\
+    inline size_t					\
+    hash<_Tp>::operator()(_Tp __val) const		\
+    { return static_cast<size_t>(__val); }
+
+  _TR1_hashtable_define_trivial_hash(bool);
+  _TR1_hashtable_define_trivial_hash(char);
+  _TR1_hashtable_define_trivial_hash(signed char);
+  _TR1_hashtable_define_trivial_hash(unsigned char);
+  _TR1_hashtable_define_trivial_hash(wchar_t);
+  _TR1_hashtable_define_trivial_hash(short);
+  _TR1_hashtable_define_trivial_hash(int);
+  _TR1_hashtable_define_trivial_hash(long);
+  _TR1_hashtable_define_trivial_hash(long long);
+  _TR1_hashtable_define_trivial_hash(unsigned short);
+  _TR1_hashtable_define_trivial_hash(unsigned int);
+  _TR1_hashtable_define_trivial_hash(unsigned long);
+  _TR1_hashtable_define_trivial_hash(unsigned long long);
+
+#undef _TR1_hashtable_define_trivial_hash
+
+  // Fowler / Noll / Vo (FNV) Hash (type FNV-1a)
+  // (Used by the next specializations of std::tr1::hash.)
+
+  /// Dummy generic implementation (for sizeof(size_t) != 4, 8).
+  template<size_t = sizeof(size_t)>
+    struct _Fnv_hash
+    {
+      static size_t
+      hash(const char* __first, size_t __length)
+      {
+	size_t __result = 0;
+	for (; __length > 0; --__length)
+	  __result = (__result * 131) + *__first++;
+	return __result;
+      }
+    };
+
+  template<>
+    struct _Fnv_hash<4>
+    {
+      static size_t
+      hash(const char* __first, size_t __length)
+      {
+	size_t __result = static_cast<size_t>(2166136261UL);
+	for (; __length > 0; --__length)
+	  {
+	    __result ^= static_cast<size_t>(*__first++);
+	    __result *= static_cast<size_t>(16777619UL);
+	  }
+	return __result;
+      }
+    };
+  
+  template<>
+    struct _Fnv_hash<8>
+    {
+      static size_t
+      hash(const char* __first, size_t __length)
+      {
+	size_t __result =
+	  static_cast<size_t>(14695981039346656037ULL);
+	for (; __length > 0; --__length)
+	  {
+	    __result ^= static_cast<size_t>(*__first++);
+	    __result *= static_cast<size_t>(1099511628211ULL);
+	  }
+	return __result;
+      }
+    };
+
+  /// Explicit specializations for float.
+  template<>
+    inline size_t
+    hash<float>::operator()(float __val) const
+    {
+      size_t __result = 0;
+      
+      // 0 and -0 both hash to zero.
+      if (__val != 0.0f)
+	__result = _Fnv_hash<>::hash(reinterpret_cast<const char*>(&__val),
+				     sizeof(__val));
+      return __result;
+    };
+
+  /// Explicit specializations for double.
+  template<>
+    inline size_t
+    hash<double>::operator()(double __val) const
+    {
+	size_t __result = 0;
+
+	// 0 and -0 both hash to zero.
+	if (__val != 0.0)
+	  __result = _Fnv_hash<>::hash(reinterpret_cast<const char*>(&__val),
+				       sizeof(__val));
+	return __result;
+    };
+
+  /// Explicit specializations for long double.
+  template<>
+    _GLIBCXX_PURE size_t
+    hash<long double>::operator()(long double __val) const;
+
+  /// Explicit specialization of member operator for non-builtin types.
+  template<>
+    _GLIBCXX_PURE size_t
+    hash<string>::operator()(string) const;
+
+  template<>
+    _GLIBCXX_PURE size_t
+    hash<const string&>::operator()(const string&) const;
+
+#ifdef _GLIBCXX_USE_WCHAR_T
+  template<>
+    _GLIBCXX_PURE size_t
+    hash<wstring>::operator()(wstring) const;
 
-#if defined(_GLIBCXX_INCLUDE_AS_TR1)
-#  include <tr1_impl/functional_hash.h>
-#else
-#  define _GLIBCXX_INCLUDE_AS_TR1
-#  define _GLIBCXX_BEGIN_NAMESPACE_TR1 namespace tr1 {
-#  define _GLIBCXX_END_NAMESPACE_TR1 }
-#  define _GLIBCXX_TR1 tr1::
-#  include <tr1_impl/functional_hash.h>
-#  undef _GLIBCXX_TR1
-#  undef _GLIBCXX_END_NAMESPACE_TR1
-#  undef _GLIBCXX_BEGIN_NAMESPACE_TR1
-#  undef _GLIBCXX_INCLUDE_AS_TR1
+  template<>
+    _GLIBCXX_PURE size_t
+    hash<const wstring&>::operator()(const wstring&) const;
 #endif
+}
+}
 
 #endif // _GLIBCXX_TR1_FUNCTIONAL_HASH_H
diff --git a/libstdc++-v3/include/tr1_impl/functional_hash.h b/libstdc++-v3/include/tr1_impl/functional_hash.h
deleted file mode 100644
index 0b963e0..0000000
--- a/libstdc++-v3/include/tr1_impl/functional_hash.h
+++ /dev/null
@@ -1,183 +0,0 @@
-// TR1 functional -*- C++ -*-
-
-// Copyright (C) 2007, 2008, 2009 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.
-
-// Under Section 7 of GPL version 3, you are granted additional
-// permissions described in the GCC Runtime Library Exception, version
-// 3.1, as published by the Free Software Foundation.
-
-// You should have received a copy of the GNU General Public License and
-// a copy of the GCC Runtime Library Exception along with this program;
-// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
-// <http://www.gnu.org/licenses/>.
-
-/** @file tr1_impl/functional_hash.h
- *  This is an internal header file, included by other library headers.
- *  You should not attempt to use it directly.
- */
-
-namespace std
-{
-_GLIBCXX_BEGIN_NAMESPACE_TR1
-
-  /// Class template hash.
-  // Declaration of default hash functor std::tr1::hash.  The types for
-  // which std::tr1::hash<T> is well-defined is in clause 6.3.3. of the PDTR.
-  template<typename _Tp>
-    struct hash : public std::unary_function<_Tp, size_t>
-    {
-      size_t
-      operator()(_Tp __val) const;
-    };
-
-  /// Partial specializations for pointer types.
-  template<typename _Tp>
-    struct hash<_Tp*> : public std::unary_function<_Tp*, size_t>
-    {
-      size_t
-      operator()(_Tp* __p) const
-      { return reinterpret_cast<size_t>(__p); }
-    };
-
-  /// Explicit specializations for integer types.
-#define _TR1_hashtable_define_trivial_hash(_Tp) 	\
-  template<>						\
-    inline size_t					\
-    hash<_Tp>::operator()(_Tp __val) const		\
-    { return static_cast<size_t>(__val); }
-
-  _TR1_hashtable_define_trivial_hash(bool);
-  _TR1_hashtable_define_trivial_hash(char);
-  _TR1_hashtable_define_trivial_hash(signed char);
-  _TR1_hashtable_define_trivial_hash(unsigned char);
-  _TR1_hashtable_define_trivial_hash(wchar_t);
-#ifdef _GLIBCXX_INCLUDE_AS_CXX0X
-  _TR1_hashtable_define_trivial_hash(char16_t);
-  _TR1_hashtable_define_trivial_hash(char32_t);
-#endif
-  _TR1_hashtable_define_trivial_hash(short);
-  _TR1_hashtable_define_trivial_hash(int);
-  _TR1_hashtable_define_trivial_hash(long);
-  _TR1_hashtable_define_trivial_hash(long long);
-  _TR1_hashtable_define_trivial_hash(unsigned short);
-  _TR1_hashtable_define_trivial_hash(unsigned int);
-  _TR1_hashtable_define_trivial_hash(unsigned long);
-  _TR1_hashtable_define_trivial_hash(unsigned long long);
-
-#undef _TR1_hashtable_define_trivial_hash
-
-  // Fowler / Noll / Vo (FNV) Hash (type FNV-1a)
-  // (Used by the next specializations of std::tr1::hash.)
-
-  /// Dummy generic implementation (for sizeof(size_t) != 4, 8).
-  template<size_t = sizeof(size_t)>
-    struct _Fnv_hash
-    {
-      static size_t
-      hash(const char* __first, size_t __length)
-      {
-	size_t __result = 0;
-	for (; __length > 0; --__length)
-	  __result = (__result * 131) + *__first++;
-	return __result;
-      }
-    };
-
-  template<>
-    struct _Fnv_hash<4>
-    {
-      static size_t
-      hash(const char* __first, size_t __length)
-      {
-	size_t __result = static_cast<size_t>(2166136261UL);
-	for (; __length > 0; --__length)
-	  {
-	    __result ^= static_cast<size_t>(*__first++);
-	    __result *= static_cast<size_t>(16777619UL);
-	  }
-	return __result;
-      }
-    };
-  
-  template<>
-    struct _Fnv_hash<8>
-    {
-      static size_t
-      hash(const char* __first, size_t __length)
-      {
-	size_t __result =
-	  static_cast<size_t>(14695981039346656037ULL);
-	for (; __length > 0; --__length)
-	  {
-	    __result ^= static_cast<size_t>(*__first++);
-	    __result *= static_cast<size_t>(1099511628211ULL);
-	  }
-	return __result;
-      }
-    };
-
-  /// Explicit specializations for float.
-  template<>
-    inline size_t
-    hash<float>::operator()(float __val) const
-    {
-      size_t __result = 0;
-      
-      // 0 and -0 both hash to zero.
-      if (__val != 0.0f)
-	__result = _Fnv_hash<>::hash(reinterpret_cast<const char*>(&__val),
-				     sizeof(__val));
-      return __result;
-    };
-
-  /// Explicit specializations for double.
-  template<>
-    inline size_t
-    hash<double>::operator()(double __val) const
-    {
-	size_t __result = 0;
-
-	// 0 and -0 both hash to zero.
-	if (__val != 0.0)
-	  __result = _Fnv_hash<>::hash(reinterpret_cast<const char*>(&__val),
-				       sizeof(__val));
-	return __result;
-    };
-
-  /// Explicit specializations for long double.
-  template<>
-    _GLIBCXX_PURE size_t
-    hash<long double>::operator()(long double __val) const;
-
-  /// Explicit specialization of member operator for non-builtin types.
-  template<>
-    _GLIBCXX_PURE size_t
-    hash<string>::operator()(string) const;
-
-  template<>
-    _GLIBCXX_PURE size_t
-    hash<const string&>::operator()(const string&) const;
-
-#ifdef _GLIBCXX_USE_WCHAR_T
-  template<>
-    _GLIBCXX_PURE size_t
-    hash<wstring>::operator()(wstring) const;
-
-  template<>
-    _GLIBCXX_PURE size_t
-    hash<const wstring&>::operator()(const wstring&) const;
-#endif
-
-_GLIBCXX_END_NAMESPACE_TR1
-}
diff --git a/libstdc++-v3/src/Makefile.am b/libstdc++-v3/src/Makefile.am
index 9513bd5..4306dd5 100644
--- a/libstdc++-v3/src/Makefile.am
+++ b/libstdc++-v3/src/Makefile.am
@@ -140,12 +140,12 @@ sources = \
 	mt_allocator.cc \
 	codecvt.cc \
 	compatibility.cc \
+	compatibility-c++0x.cc \
 	complex_io.cc \
 	ctype.cc \
 	debug.cc \
 	functexcept.cc \
 	hash_tr1.cc \
-	hash_c++0x.cc \
 	globals_io.cc \
 	hashtable_tr1.cc \
 	hashtable_c++0x.cc \
@@ -260,9 +260,9 @@ condition_variable.lo: condition_variable.cc
 condition_variable.o: condition_variable.cc
 	$(CXXCOMPILE) -std=gnu++0x -c $<
 
-hash_c++0x.lo: hash_c++0x.cc
+compatibility-c++0x.lo: compatibility-c++0x.cc
 	$(LTCXXCOMPILE) -std=gnu++0x -c $<
-hash_c++0x.o: hash_c++0x.cc
+compatibility-c++0x.o: compatibility-c++0x.cc
 	$(CXXCOMPILE) -std=gnu++0x -c $<
 
 hashtable_c++0x.lo: hashtable_c++0x.cc
diff --git a/libstdc++-v3/src/Makefile.in b/libstdc++-v3/src/Makefile.in
index 9c03ac4..8cc950f 100644
--- a/libstdc++-v3/src/Makefile.in
+++ b/libstdc++-v3/src/Makefile.in
@@ -87,8 +87,8 @@ LTLIBRARIES = $(toolexeclib_LTLIBRARIES)
 am__DEPENDENCIES_1 =
 am__libstdc___la_SOURCES_DIST = atomic.cc bitmap_allocator.cc \
 	pool_allocator.cc mt_allocator.cc codecvt.cc compatibility.cc \
-	complex_io.cc ctype.cc debug.cc functexcept.cc hash_tr1.cc \
-	hash_c++0x.cc globals_io.cc hashtable_tr1.cc \
+	compatibility-c++0x.cc complex_io.cc ctype.cc debug.cc \
+	functexcept.cc hash_tr1.cc globals_io.cc hashtable_tr1.cc \
 	hashtable_c++0x.cc ios.cc ios_failure.cc ios_init.cc \
 	ios_locale.cc limits.cc limits_c++0x.cc list.cc debug_list.cc \
 	locale.cc locale_init.cc locale_facets.cc localename.cc \
@@ -113,18 +113,18 @@ am__objects_1 = atomicity.lo codecvt_members.lo collate_members.lo \
 am__objects_4 = basic_file.lo c++locale.lo $(am__objects_2) \
 	$(am__objects_3)
 am__objects_5 = atomic.lo bitmap_allocator.lo pool_allocator.lo \
-	mt_allocator.lo codecvt.lo compatibility.lo complex_io.lo \
-	ctype.lo debug.lo functexcept.lo hash_tr1.lo hash_c++0x.lo \
-	globals_io.lo hashtable_tr1.lo hashtable_c++0x.lo ios.lo \
-	ios_failure.lo ios_init.lo ios_locale.lo limits.lo \
-	limits_c++0x.lo list.lo debug_list.lo locale.lo locale_init.lo \
-	locale_facets.lo localename.lo math_stubs_float.lo \
-	math_stubs_long_double.lo stdexcept.lo strstream.lo \
-	system_error.lo tree.lo allocator-inst.lo concept-inst.lo \
-	fstream-inst.lo ext-inst.lo ios-inst.lo iostream-inst.lo \
-	istream-inst.lo istream.lo locale-inst.lo misc-inst.lo \
-	ostream-inst.lo sstream-inst.lo streambuf-inst.lo streambuf.lo \
-	string-inst.lo valarray-inst.lo wlocale-inst.lo \
+	mt_allocator.lo codecvt.lo compatibility.lo \
+	compatibility-c++0x.lo complex_io.lo ctype.lo debug.lo \
+	functexcept.lo hash_tr1.lo globals_io.lo hashtable_tr1.lo \
+	hashtable_c++0x.lo ios.lo ios_failure.lo ios_init.lo \
+	ios_locale.lo limits.lo limits_c++0x.lo list.lo debug_list.lo \
+	locale.lo locale_init.lo locale_facets.lo localename.lo \
+	math_stubs_float.lo math_stubs_long_double.lo stdexcept.lo \
+	strstream.lo system_error.lo tree.lo allocator-inst.lo \
+	concept-inst.lo fstream-inst.lo ext-inst.lo ios-inst.lo \
+	iostream-inst.lo istream-inst.lo istream.lo locale-inst.lo \
+	misc-inst.lo ostream-inst.lo sstream-inst.lo streambuf-inst.lo \
+	streambuf.lo string-inst.lo valarray-inst.lo wlocale-inst.lo \
 	wstring-inst.lo mutex.lo condition_variable.lo chrono.lo \
 	thread.lo future.lo $(am__objects_1) $(am__objects_4)
 am_libstdc___la_OBJECTS = $(am__objects_5)
@@ -382,12 +382,12 @@ sources = \
 	mt_allocator.cc \
 	codecvt.cc \
 	compatibility.cc \
+	compatibility-c++0x.cc \
 	complex_io.cc \
 	ctype.cc \
 	debug.cc \
 	functexcept.cc \
 	hash_tr1.cc \
-	hash_c++0x.cc \
 	globals_io.cc \
 	hashtable_tr1.cc \
 	hashtable_c++0x.cc \
@@ -891,9 +891,9 @@ condition_variable.lo: condition_variable.cc
 condition_variable.o: condition_variable.cc
 	$(CXXCOMPILE) -std=gnu++0x -c $<
 
-hash_c++0x.lo: hash_c++0x.cc
+compatibility-c++0x.lo: compatibility-c++0x.cc
 	$(LTCXXCOMPILE) -std=gnu++0x -c $<
-hash_c++0x.o: hash_c++0x.cc
+compatibility-c++0x.o: compatibility-c++0x.cc
 	$(CXXCOMPILE) -std=gnu++0x -c $<
 
 hashtable_c++0x.lo: hashtable_c++0x.cc
diff --git a/libstdc++-v3/src/hash_c++0x.cc b/libstdc++-v3/src/compatibility-c++0x.cc
index 5bdbf0c..0e92135 100644
--- a/libstdc++-v3/src/hash_c++0x.cc
+++ b/libstdc++-v3/src/compatibility-c++0x.cc
@@ -1,6 +1,6 @@
-// std::hash definitions -*- C++ -*-
+// Compatibility symbols for previous versions, C++0x bits -*- C++ -*-
 
-// Copyright (C) 2007, 2009 Free Software Foundation, Inc.
+// Copyright (C) 2009 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
@@ -25,15 +25,38 @@
 #include <cstddef>
 #include <string>
 #include <cmath>
-#include <functional>
 #include <system_error>
 
 #ifndef __GXX_EXPERIMENTAL_CXX0X__
-# error "hash_c++0x.cc must be compiled with -std=gnu++0x"
+# error "compatibility-c++0x.cc must be compiled with -std=gnu++0x"
 #endif
 
 namespace std
 {
+  // We need these due to the symbols exported since GLIBCXX_3.4.10.
+  // See libstdc++/41662 for details.
+
+  template<typename _Tp>
+    struct hash : public std::unary_function<_Tp, size_t>
+    {
+      size_t
+      operator()(_Tp __val) const;
+    };
+
+  /// Dummy generic implementation (for sizeof(size_t) != 4, 8).
+  template<size_t = sizeof(size_t)>
+    struct _Fnv_hash
+    {
+      static size_t
+      hash(const char* __first, size_t __length)
+      {
+	size_t __result = 0;
+	for (; __length > 0; --__length)
+	  __result = (__result * 131) + *__first++;
+	return __result;
+      }
+    };
+
 #include "hash.cc"
 
   template<>
diff --git a/libstdc++-v3/src/hash.cc b/libstdc++-v3/src/hash.cc
index c776ed5..cc23858 100644
--- a/libstdc++-v3/src/hash.cc
+++ b/libstdc++-v3/src/hash.cc
@@ -26,7 +26,7 @@
   // 10 bytes -> 12 bytes) and resort to frexp.
   template<>
     size_t
-    hash<long double>::operator()(long double __val) const throw ()
+    hash<long double>::operator()(long double __val) const
     {
       size_t __result = 0;
 
@@ -59,7 +59,7 @@
 
   template<>
     size_t
-    hash<const string&>::operator()(const string& __s) const throw ()
+    hash<const string&>::operator()(const string& __s) const
     { return _Fnv_hash<>::hash(__s.data(), __s.length()); }
 
 #ifdef _GLIBCXX_USE_WCHAR_T
@@ -73,7 +73,7 @@
 
   template<>
     size_t
-    hash<const wstring&>::operator()(const wstring& __s) const throw ()
+    hash<const wstring&>::operator()(const wstring& __s) const
     {
       const char* __p = reinterpret_cast<const char*>(__s.data());
       return _Fnv_hash<>::hash(__p, __s.length() * sizeof(wchar_t));
diff --git a/libstdc++-v3/testsuite/23_containers/unordered_map/requirements/explicit_instantiation/2.cc b/libstdc++-v3/testsuite/23_containers/unordered_map/requirements/explicit_instantiation/2.cc
index f6b5fe3..8517908 100644
--- a/libstdc++-v3/testsuite/23_containers/unordered_map/requirements/explicit_instantiation/2.cc
+++ b/libstdc++-v3/testsuite/23_containers/unordered_map/requirements/explicit_instantiation/2.cc
@@ -24,5 +24,6 @@
 #include <testsuite_hooks.h>
 #include <testsuite_api.h>
 
-typedef __gnu_test::NonDefaultConstructible inst_type;
-template class std::unordered_map<inst_type, inst_type>;
+typedef __gnu_test::NonDefaultConstructible      inst_type;
+typedef __gnu_test::NonDefaultConstructible_hash hash_type;
+template class std::unordered_map<inst_type, inst_type, hash_type>;
diff --git a/libstdc++-v3/testsuite/23_containers/unordered_multimap/requirements/explicit_instantiation/2.cc b/libstdc++-v3/testsuite/23_containers/unordered_multimap/requirements/explicit_instantiation/2.cc
index e26428d..2eef371 100644
--- a/libstdc++-v3/testsuite/23_containers/unordered_multimap/requirements/explicit_instantiation/2.cc
+++ b/libstdc++-v3/testsuite/23_containers/unordered_multimap/requirements/explicit_instantiation/2.cc
@@ -24,5 +24,6 @@
 #include <testsuite_hooks.h>
 #include <testsuite_api.h>
 
-typedef __gnu_test::NonDefaultConstructible inst_type;
-template class std::unordered_multimap<inst_type, inst_type>;
+typedef __gnu_test::NonDefaultConstructible      inst_type;
+typedef __gnu_test::NonDefaultConstructible_hash hash_type;
+template class std::unordered_multimap<inst_type, inst_type, hash_type>;
diff --git a/libstdc++-v3/testsuite/23_containers/unordered_multiset/requirements/explicit_instantiation/2.cc b/libstdc++-v3/testsuite/23_containers/unordered_multiset/requirements/explicit_instantiation/2.cc
index d2a120a..5764e92 100644
--- a/libstdc++-v3/testsuite/23_containers/unordered_multiset/requirements/explicit_instantiation/2.cc
+++ b/libstdc++-v3/testsuite/23_containers/unordered_multiset/requirements/explicit_instantiation/2.cc
@@ -24,4 +24,6 @@
 #include <testsuite_hooks.h>
 #include <testsuite_api.h>
 
-template class std::unordered_multiset<__gnu_test::NonDefaultConstructible>;
+typedef __gnu_test::NonDefaultConstructible      inst_type;
+typedef __gnu_test::NonDefaultConstructible_hash hash_type;
+template class std::unordered_multiset<inst_type, hash_type>;
diff --git a/libstdc++-v3/testsuite/23_containers/unordered_set/requirements/explicit_instantiation/2.cc b/libstdc++-v3/testsuite/23_containers/unordered_set/requirements/explicit_instantiation/2.cc
index 13e9e37..e227604 100644
--- a/libstdc++-v3/testsuite/23_containers/unordered_set/requirements/explicit_instantiation/2.cc
+++ b/libstdc++-v3/testsuite/23_containers/unordered_set/requirements/explicit_instantiation/2.cc
@@ -24,4 +24,6 @@
 #include <testsuite_hooks.h>
 #include <testsuite_api.h>
 
-template class std::unordered_set<__gnu_test::NonDefaultConstructible>;
+typedef __gnu_test::NonDefaultConstructible      inst_type;
+typedef __gnu_test::NonDefaultConstructible_hash hash_type;
+template class std::unordered_set<inst_type, hash_type>;
diff --git a/libstdc++-v3/testsuite/util/testsuite_api.h b/libstdc++-v3/testsuite/util/testsuite_api.h
index 772349b..4dc4a6f 100644
--- a/libstdc++-v3/testsuite/util/testsuite_api.h
+++ b/libstdc++-v3/testsuite/util/testsuite_api.h
@@ -19,6 +19,7 @@
 // <http://www.gnu.org/licenses/>.
 //
 
+#include <cstddef>
 #include <exception>
 #include <testsuite_hooks.h>
 
@@ -103,6 +104,14 @@ namespace __gnu_test
   operator<(const NonDefaultConstructible&, const NonDefaultConstructible&)
   { return false; }
 
+  // For 23 unordered_* requirements.
+  struct NonDefaultConstructible_hash
+  {
+    size_t
+    operator()(NonDefaultConstructible) const
+    { return 1; }
+  };
+
   // For 26 numeric algorithms requirements, need addable,
   // subtractable, multiplicable.
   inline NonDefaultConstructible
@@ -141,6 +150,6 @@ namespace __gnu_test
       operator()() const
       { return result_type(2); }
     };
-
 }
+
 #endif