Implement DR 396 [Ready].

2008-09-23  Paolo Carlini  <paolo.carlini@oracle.com>

	Implement DR 396 [Ready].
	* include/std/bitset (bitset<>::bitset(const std::basic_string<>&,
	size_t, size_t, _CharT, _CharT), bitset<>::bitset(const char*,
	char, char), bitset<>::to_string(_CharT, _CharT),
	bitset<>::_M_copy_from_string(const std::basic_string<>&, size_t,
	size_t, _CharT, _CharT), bitset<>::_M_copy_to_string
	(std::basic_string<>&, _CharT, _CharT), bitset<>::_M_copy_from_ptr(
	const _CharT*, size_t, size_t, size_t, _CharT, _CharT)): Add.
	(operator>>(std::basic_istream<>&, bitset<_Nb>&), operator<<(
	std::basic_ostream<>&, const bitset<_Nb>&)): Adjust.
	* include/debug/bitset (bitset<>::bitset(const std::basic_string<>&,
	size_t, size_t, _CharT, _CharT), bitset<>::bitset(const char*,
	char, char), bitset<>::to_string(_CharT, _CharT)): Add.
	* doc/xml/manual/intro.xml: Add an entry for DR 396.
	* testsuite/23_containers/bitset/cons/dr396.cc: Add.
	* testsuite/23_containers/bitset/to_string/dr396.cc: Likewise.

From-SVN: r140607

6 files changed, 323 insertions, 49 deletions

diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index 92e5267..1646262 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,22 @@
+2008-09-23  Paolo Carlini  <paolo.carlini@oracle.com>
+
+	Implement DR 396 [Ready].
+	* include/std/bitset (bitset<>::bitset(const std::basic_string<>&,
+	size_t, size_t, _CharT, _CharT), bitset<>::bitset(const char*,
+	char, char), bitset<>::to_string(_CharT, _CharT),
+	bitset<>::_M_copy_from_string(const std::basic_string<>&, size_t,
+	size_t, _CharT, _CharT), bitset<>::_M_copy_to_string
+	(std::basic_string<>&, _CharT, _CharT), bitset<>::_M_copy_from_ptr(
+	const _CharT*, size_t, size_t, size_t, _CharT, _CharT)): Add.
+	(operator>>(std::basic_istream<>&, bitset<_Nb>&), operator<<(
+	std::basic_ostream<>&, const bitset<_Nb>&)): Adjust.
+	* include/debug/bitset (bitset<>::bitset(const std::basic_string<>&,
+	size_t, size_t, _CharT, _CharT), bitset<>::bitset(const char*,
+	char, char), bitset<>::to_string(_CharT, _CharT)): Add.
+	* doc/xml/manual/intro.xml: Add an entry for DR 396.
+	* testsuite/23_containers/bitset/cons/dr396.cc: Add.
+	* testsuite/23_containers/bitset/to_string/dr396.cc: Likewise.
+
 2008-09-23  Chris Fairles <cfairles@gcc.gnu.org>
 
 	* include/std/chrono: If _GLIBCXX_USE_MONOTONIC_CLOCK is defined, don't
diff --git a/libstdc++-v3/doc/xml/manual/intro.xml b/libstdc++-v3/doc/xml/manual/intro.xml
index 08e107a..eb9652f 100644
--- a/libstdc++-v3/doc/xml/manual/intro.xml
+++ b/libstdc++-v3/doc/xml/manual/intro.xml
@@ -522,6 +522,12 @@
     <listitem><para>Change it to return a <code>const T&amp;</code>.
     </para></listitem></varlistentry>
 
+    <varlistentry><term><ulink url="../ext/lwg-active.html#396">396</ulink>:
+        <emphasis>what are characters zero and one</emphasis>
+    </term>
+    <listitem><para>Implement the proposed resolution.
+    </para></listitem></varlistentry>
+
     <varlistentry><term><ulink url="../ext/lwg-defects.html#402">402</ulink>:
         <emphasis>Wrong new expression in [some_]allocator::construct</emphasis>
     </term>
diff --git a/libstdc++-v3/include/debug/bitset b/libstdc++-v3/include/debug/bitset
index 75474c8..28e0282 100644
--- a/libstdc++-v3/include/debug/bitset
+++ b/libstdc++-v3/include/debug/bitset
@@ -1,6 +1,7 @@
 // Debugging bitset implementation -*- C++ -*-
 
-// Copyright (C) 2003, 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
+// Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008
+// 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
@@ -125,20 +126,31 @@ namespace __debug
 
       bitset(unsigned long __val) : _Base(__val) { }
 
-      template<typename _CharT, typename _Traits, typename _Allocator>
+      template<typename _CharT, typename _Traits, typename _Alloc>
         explicit
-        bitset(const std::basic_string<_CharT,_Traits,_Allocator>& __str,
-	       typename std::basic_string<_CharT,_Traits,_Allocator>::size_type
+        bitset(const std::basic_string<_CharT, _Traits, _Alloc>& __str,
+	       typename std::basic_string<_CharT, _Traits, _Alloc>::size_type
 	       __pos = 0,
-	       typename std::basic_string<_CharT,_Traits,_Allocator>::size_type
-	       __n = (std::basic_string<_CharT,_Traits,_Allocator>::npos))
+	       typename std::basic_string<_CharT, _Traits, _Alloc>::size_type
+	       __n = (std::basic_string<_CharT, _Traits, _Alloc>::npos))
 	: _Base(__str, __pos, __n) { }
 
       // _GLIBCXX_RESOLVE_LIB_DEFECTS
+      // 396. what are characters zero and one.
+      template<class _CharT, class _Traits, class _Alloc>
+	bitset(const std::basic_string<_CharT, _Traits, _Alloc>& __str,
+	       typename std::basic_string<_CharT, _Traits, _Alloc>::size_type
+	       __pos,
+	       typename std::basic_string<_CharT, _Traits, _Alloc>::size_type
+	       __n,
+	       _CharT __zero, _CharT __one = _CharT('1'))
+	: _Base(__str, __pos, __n, __zero, __one) { }
+
+      // _GLIBCXX_RESOLVE_LIB_DEFECTS
       // 778. std::bitset does not have any constructor taking a string literal
       explicit
-      bitset(const char* __s)
-      : _Base(__s) { }
+      bitset(const char* __s, char __zero = '0', char __one = '1')
+      : _Base(__s, __zero, __one) { }
 
       bitset(const _Base& __x) : _Base(__x), _Safe_base() { }
 
@@ -245,10 +257,20 @@ namespace __debug
 
       using _Base::to_ulong;
 
-      template <typename _CharT, typename _Traits, typename _Allocator>
-        std::basic_string<_CharT, _Traits, _Allocator>
+      template <typename _CharT, typename _Traits, typename _Alloc>
+        std::basic_string<_CharT, _Traits, _Alloc>
         to_string() const
-        { return _M_base().template to_string<_CharT, _Traits, _Allocator>(); }
+        { return _M_base().template to_string<_CharT, _Traits, _Alloc>(); }
+
+      // _GLIBCXX_RESOLVE_LIB_DEFECTS
+      // 396. what are characters zero and one.
+      template<class _CharT, class _Traits, class _Alloc>
+	std::basic_string<_CharT, _Traits, _Alloc>
+	to_string(_CharT __zero, _CharT __one = _CharT('1')) const
+	{
+	  return _M_base().template
+	    to_string<_CharT, _Traits, _Alloc>(__zero, __one);
+	}
 
       // _GLIBCXX_RESOLVE_LIB_DEFECTS
       // 434. bitset::to_string() hard to use.
@@ -257,6 +279,14 @@ namespace __debug
         to_string() const
         { return to_string<_CharT, _Traits, std::allocator<_CharT> >(); }
 
+      // _GLIBCXX_RESOLVE_LIB_DEFECTS
+      // 396. what are characters zero and one.
+      template<class _CharT, class _Traits>
+	std::basic_string<_CharT, _Traits, std::allocator<_CharT> >
+	to_string(_CharT __zero, _CharT __one = _CharT('1')) const
+	{ return to_string<_CharT, _Traits,
+	                   std::allocator<_CharT> >(__zero, __one); }
+
       template<typename _CharT>
         std::basic_string<_CharT, std::char_traits<_CharT>,
                           std::allocator<_CharT> >
@@ -266,11 +296,27 @@ namespace __debug
                            std::allocator<_CharT> >();
         }
 
+      template<class _CharT>
+	std::basic_string<_CharT, std::char_traits<_CharT>,
+	                  std::allocator<_CharT> >
+	to_string(_CharT __zero, _CharT __one = _CharT('1')) const
+	{
+	  return to_string<_CharT, std::char_traits<_CharT>,
+	                   std::allocator<_CharT> >(__zero, __one);
+	}
+
       std::basic_string<char, std::char_traits<char>, std::allocator<char> >
-        to_string() const
-        {
-          return to_string<char,std::char_traits<char>,std::allocator<char> >();
-        }
+      to_string() const
+      {
+	return to_string<char,std::char_traits<char>,std::allocator<char> >();
+      }
+
+      std::basic_string<char, std::char_traits<char>, std::allocator<char> >
+      to_string(char __zero, char __one = '1') const
+      {
+	return to_string<char, std::char_traits<char>,
+	                 std::allocator<char> >(__zero, __one);
+      }
 
       using _Base::count;
       using _Base::size;
diff --git a/libstdc++-v3/include/std/bitset b/libstdc++-v3/include/std/bitset
index 50015db..9a1ba8d 100644
--- a/libstdc++-v3/include/std/bitset
+++ b/libstdc++-v3/include/std/bitset
@@ -764,7 +764,8 @@ _GLIBCXX_BEGIN_NESTED_NAMESPACE(std, _GLIBCXX_STD_D)
 	    __throw_out_of_range(__N("bitset::bitset initial position "
 				     "not valid"));
 	  _M_copy_from_string(__s, __position,
-			      std::basic_string<_CharT, _Traits, _Alloc>::npos);
+			      std::basic_string<_CharT, _Traits, _Alloc>::npos,
+			      _CharT('0'), _CharT('1'));
 	}
 
       /**
@@ -784,15 +785,33 @@ _GLIBCXX_BEGIN_NESTED_NAMESPACE(std, _GLIBCXX_STD_D)
 	  if (__position > __s.size())
 	    __throw_out_of_range(__N("bitset::bitset initial position "
 				     "not valid"));
-	  _M_copy_from_string(__s, __position, __n);
+	  _M_copy_from_string(__s, __position, __n, _CharT('0'), _CharT('1'));
+	}
+
+      // _GLIBCXX_RESOLVE_LIB_DEFECTS
+      // 396. what are characters zero and one.
+      template<class _CharT, class _Traits, class _Alloc>
+	bitset(const std::basic_string<_CharT, _Traits, _Alloc>& __s,
+	       size_t __position, size_t __n,
+	       _CharT __zero, _CharT __one = _CharT('1'))
+	: _Base()
+	{
+	  if (__position > __s.size())
+	    __throw_out_of_range(__N("bitset::bitset initial position "
+				     "not valid"));
+	  _M_copy_from_string(__s, __position, __n, __zero, __one);
 	}
 
       // _GLIBCXX_RESOLVE_LIB_DEFECTS
       // 778. std::bitset does not have any constructor taking a string literal
       explicit
-      bitset(const char* __s)
+      bitset(const char* __s, char __zero = '0', char __one = '1')
       : _Base()
-      { _M_copy_from_ptr(__s, char_traits<char>::length(__s), 0, size_t(-1)); }
+      {
+	_M_copy_from_ptr<char, char_traits<char> >(__s,
+			       char_traits<char>::length(__s), 0, size_t(-1),
+						   __zero, __one);
+      }
 
       // 23.3.5.2 bitset operations:
       //@{
@@ -1028,7 +1047,18 @@ _GLIBCXX_BEGIN_NESTED_NAMESPACE(std, _GLIBCXX_STD_D)
 	to_string() const
 	{
 	  std::basic_string<_CharT, _Traits, _Alloc> __result;
-	  _M_copy_to_string(__result);
+	  _M_copy_to_string(__result, _CharT('0'), _CharT('1'));
+	  return __result;
+	}
+
+      // _GLIBCXX_RESOLVE_LIB_DEFECTS
+      // 396. what are characters zero and one.
+      template<class _CharT, class _Traits, class _Alloc>
+	std::basic_string<_CharT, _Traits, _Alloc>
+	to_string(_CharT __zero, _CharT __one = _CharT('1')) const
+	{
+	  std::basic_string<_CharT, _Traits, _Alloc> __result;
+	  _M_copy_to_string(__result, __zero, __one);
 	  return __result;
 	}
 
@@ -1039,6 +1069,14 @@ _GLIBCXX_BEGIN_NESTED_NAMESPACE(std, _GLIBCXX_STD_D)
 	to_string() const
 	{ return to_string<_CharT, _Traits, std::allocator<_CharT> >(); }
 
+      // _GLIBCXX_RESOLVE_LIB_DEFECTS
+      // 396. what are characters zero and one.
+      template<class _CharT, class _Traits>
+	std::basic_string<_CharT, _Traits, std::allocator<_CharT> >
+	to_string(_CharT __zero, _CharT __one = _CharT('1')) const
+	{ return to_string<_CharT, _Traits,
+	                   std::allocator<_CharT> >(__zero, __one); }
+
       template<class _CharT>
 	std::basic_string<_CharT, std::char_traits<_CharT>,
 	                  std::allocator<_CharT> >
@@ -1048,6 +1086,15 @@ _GLIBCXX_BEGIN_NESTED_NAMESPACE(std, _GLIBCXX_STD_D)
 	                   std::allocator<_CharT> >();
 	}
 
+      template<class _CharT>
+	std::basic_string<_CharT, std::char_traits<_CharT>,
+	                  std::allocator<_CharT> >
+	to_string(_CharT __zero, _CharT __one = _CharT('1')) const
+	{
+	  return to_string<_CharT, std::char_traits<_CharT>,
+	                   std::allocator<_CharT> >(__zero, __one);
+	}
+
       std::basic_string<char, std::char_traits<char>, std::allocator<char> >
       to_string() const
       {
@@ -1055,20 +1102,43 @@ _GLIBCXX_BEGIN_NESTED_NAMESPACE(std, _GLIBCXX_STD_D)
 	                 std::allocator<char> >();
       }
 
+      std::basic_string<char, std::char_traits<char>, std::allocator<char> >
+      to_string(char __zero, char __one = '1') const
+      {
+	return to_string<char, std::char_traits<char>,
+	                 std::allocator<char> >(__zero, __one);
+      }
+
       // Helper functions for string operations.
-      template<class _CharT>
+      template<class _CharT, class _Traits>
         void
-        _M_copy_from_ptr(const _CharT*, size_t, size_t, size_t);
+        _M_copy_from_ptr(const _CharT*, size_t, size_t, size_t,
+			 _CharT, _CharT);
+
+      template<class _CharT, class _Traits, class _Alloc>
+	void
+	_M_copy_from_string(const std::basic_string<_CharT,
+			    _Traits, _Alloc>& __s, size_t __pos, size_t __n,
+			    _CharT __zero, _CharT __one)
+	{ _M_copy_from_ptr<_CharT, _Traits>(__s.data(), __s.size(), __pos, __n,
+					    __zero, __one); }
+
+      template<class _CharT, class _Traits, class _Alloc>
+	void
+        _M_copy_to_string(std::basic_string<_CharT, _Traits, _Alloc>&,
+			  _CharT, _CharT) const;
 
+      // NB: Backward compat.
       template<class _CharT, class _Traits, class _Alloc>
 	void
 	_M_copy_from_string(const std::basic_string<_CharT,
 			    _Traits, _Alloc>& __s, size_t __pos, size_t __n)
-	{ _M_copy_from_ptr(__s.data(), __s.size(), __pos, __n); }
+	{ _M_copy_from_string(__s, __pos, __n, _CharT('0'), _CharT('1')); }
 
       template<class _CharT, class _Traits, class _Alloc>
 	void
-	_M_copy_to_string(std::basic_string<_CharT, _Traits, _Alloc>&) const;
+        _M_copy_to_string(std::basic_string<_CharT, _Traits,_Alloc>& __s) const
+	{ _M_copy_to_string(__s, _CharT('0'), _CharT('1')); }
 
       /// Returns the number of bits which are set.
       size_t
@@ -1166,26 +1236,23 @@ _GLIBCXX_BEGIN_NESTED_NAMESPACE(std, _GLIBCXX_STD_D)
 
   // Definitions of non-inline member functions.
   template<size_t _Nb>
-    template<class _CharT>
+    template<class _CharT, class _Traits>
       void
       bitset<_Nb>::
       _M_copy_from_ptr(const _CharT* __s, size_t __len,
-		       size_t __pos, size_t __n)
+		       size_t __pos, size_t __n, _CharT __zero, _CharT __one)
       {
 	reset();
 	const size_t __nbits = std::min(_Nb, std::min(__n, __len - __pos));
 	for (size_t __i = __nbits; __i > 0; --__i)
 	  {
-	    switch(__s[__pos + __nbits - __i])
-	      {
-	      case '0':
-		break;
-	      case '1':
-		_Unchecked_set(__i - 1);
-		break;
-	      default:
-		__throw_invalid_argument(__N("bitset::_M_copy_from_ptr"));
-	      }
+	    const _CharT __c = __s[__pos + __nbits - __i];
+	    if (_Traits::eq(__c, __zero))
+	      ;
+	    else if (_Traits::eq(__c, __one))
+	      _Unchecked_set(__i - 1);
+	    else
+	      __throw_invalid_argument(__N("bitset::_M_copy_from_ptr"));
 	  }
       }
 
@@ -1193,12 +1260,13 @@ _GLIBCXX_BEGIN_NESTED_NAMESPACE(std, _GLIBCXX_STD_D)
     template<class _CharT, class _Traits, class _Alloc>
       void
       bitset<_Nb>::
-      _M_copy_to_string(std::basic_string<_CharT, _Traits, _Alloc>& __s) const
+      _M_copy_to_string(std::basic_string<_CharT, _Traits, _Alloc>& __s,
+			_CharT __zero, _CharT __one) const
       {
-	__s.assign(_Nb, '0');
+	__s.assign(_Nb, __zero);
 	for (size_t __i = _Nb; __i > 0; --__i)
 	  if (_Unchecked_test(__i - 1))
-	    __s[_Nb - __i] = '1';
+	    _Traits::assign(__s[_Nb - __i], __one);
       }
 
   // 23.3.5.3 bitset operations:
@@ -1259,16 +1327,17 @@ _GLIBCXX_BEGIN_NESTED_NAMESPACE(std, _GLIBCXX_STD_D)
       std::basic_string<_CharT, _Traits> __tmp;
       __tmp.reserve(_Nb);
 
+      // _GLIBCXX_RESOLVE_LIB_DEFECTS
+      // 303. Bitset input operator underspecified
+      const char_type __zero = __is.widen('0');
+      const char_type __one = __is.widen('1');
+
       typename __ios_base::iostate __state = __ios_base::goodbit;
       typename __istream_type::sentry __sentry(__is);
       if (__sentry)
 	{
 	  try
 	    {
-	      // _GLIBCXX_RESOLVE_LIB_DEFECTS
-	      // 303. Bitset input operator underspecified
-	      const char_type __zero = __is.widen('0');
-	      const char_type __one = __is.widen('1');
 	      for (size_t __i = _Nb; __i > 0; --__i)
 		{
 		  static typename _Traits::int_type __eof = _Traits::eof();
@@ -1282,10 +1351,10 @@ _GLIBCXX_BEGIN_NESTED_NAMESPACE(std, _GLIBCXX_STD_D)
 		  else
 		    {
 		      const char_type __c2 = _Traits::to_char_type(__c1);
-		      if (__c2 == __zero)
-			__tmp.push_back('0');
-		      else if (__c2 == __one)
-			__tmp.push_back('1');
+		      if (_Traits::eq(__c2, __zero))
+			__tmp.push_back(__zero);
+		      else if (_Traits::eq(__c2, __one))
+			__tmp.push_back(__one);
 		      else if (_Traits::
 			       eq_int_type(__is.rdbuf()->sputbackc(__c2),
 					   __eof))
@@ -1308,7 +1377,8 @@ _GLIBCXX_BEGIN_NESTED_NAMESPACE(std, _GLIBCXX_STD_D)
       if (__tmp.empty() && _Nb)
 	__state |= __ios_base::failbit;
       else
-	__x._M_copy_from_string(__tmp, static_cast<size_t>(0), _Nb);
+	__x._M_copy_from_string(__tmp, static_cast<size_t>(0), _Nb,
+				__zero, __one);
       if (__state)
 	__is.setstate(__state);
       return __is;
@@ -1320,7 +1390,11 @@ _GLIBCXX_BEGIN_NESTED_NAMESPACE(std, _GLIBCXX_STD_D)
 	       const bitset<_Nb>& __x)
     {
       std::basic_string<_CharT, _Traits> __tmp;
-      __x._M_copy_to_string(__tmp);
+
+      // _GLIBCXX_RESOLVE_LIB_DEFECTS
+      // 396. what are characters zero and one.
+      const ctype<_CharT>& __ct = use_facet<ctype<_CharT> >(__os.getloc());
+      __x._M_copy_to_string(__tmp, __ct.widen('0'), __ct.widen('1'));
       return __os << __tmp;
     }
   //@}
diff --git a/libstdc++-v3/testsuite/23_containers/bitset/cons/dr396.cc b/libstdc++-v3/testsuite/23_containers/bitset/cons/dr396.cc
new file mode 100644
index 0000000..3c8a576
--- /dev/null
+++ b/libstdc++-v3/testsuite/23_containers/bitset/cons/dr396.cc
@@ -0,0 +1,64 @@
+// 2009-09-23  Paolo Carlini  <paolo.carlini@oracle.com>
+
+// Copyright (C) 2008 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 2, 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 COPYING.  If not, write to the Free
+// Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
+// USA.
+
+#include <bitset>
+#include <testsuite_hooks.h>
+
+// DR 396. what are characters zero and one.
+void test01()
+{
+  bool test __attribute__((unused)) = true;
+
+  std::bitset<4> z1("bbab", 'a', 'b');
+  std::bitset<4> z1_ref(std::string("bbab"), 0, std::string::npos, 'a', 'b');
+  VERIFY( z1.to_string('a', 'b') == "bbab" );
+  VERIFY( z1 == z1_ref );
+
+  std::bitset<4> z2("11a1", 'a');
+  std::bitset<4> z2_ref(std::string("11a1"), 0, std::string::npos, 'a');
+  VERIFY( z2.to_string('a') == "11a1" );
+  VERIFY( z2 == z2_ref );
+
+  std::bitset<8> z3("babb", 'a', 'b');
+  std::bitset<8> z3_ref(std::string("babb"), 0, std::string::npos, 'a', 'b');
+  VERIFY( z3.to_string('a', 'b') == "aaaababb" );
+  VERIFY( z3 == z3_ref );
+
+  std::bitset<8> z4("1a11", 'a');
+  std::bitset<8> z4_ref(std::string("1a11"), 0, std::string::npos, 'a');
+  VERIFY( z4.to_string('a') == "aaaa1a11" );
+  VERIFY( z4 == z4_ref );
+
+  std::bitset<2> z5("bbab", 'a', 'b');
+  std::bitset<2> z5_ref(std::string("bbab"), 0, std::string::npos, 'a', 'b');
+  VERIFY( z5.to_string('a', 'b') == "bb" );
+  VERIFY( z5 == z5_ref );
+
+  std::bitset<2> z6("11a1", 'a');
+  std::bitset<2> z6_ref(std::string("11a1"), 0, std::string::npos, 'a');
+  VERIFY( z6.to_string('a') == "11" );
+  VERIFY( z6 == z6_ref );
+}
+
+int main()
+{
+  test01();
+  return 0;
+}
diff --git a/libstdc++-v3/testsuite/23_containers/bitset/to_string/dr396.cc b/libstdc++-v3/testsuite/23_containers/bitset/to_string/dr396.cc
new file mode 100644
index 0000000..ac31df1
--- /dev/null
+++ b/libstdc++-v3/testsuite/23_containers/bitset/to_string/dr396.cc
@@ -0,0 +1,65 @@
+// 2008-09-23  Paolo Carlini  <pcarlini@suse.de>
+
+// Copyright (C) 2008 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 2, 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 COPYING.  If not, write to the Free
+// Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
+// USA.
+
+// 23.3.5.2 bitset members
+
+#include <bitset>
+#include <testsuite_hooks.h>
+
+// DR 396. what are characters zero and one.
+void test01()
+{
+  using namespace std;
+  bool test __attribute__((unused)) = true;
+
+  bitset<5> b5;
+  string s0 = b5.to_string<char, char_traits<char>, allocator<char> >('a', 'b');
+  VERIFY( s0 == "aaaaa" );
+
+  string s1 = b5.to_string<char, char_traits<char>, allocator<char> >('b');
+  VERIFY( s1 == "bbbbb" );
+
+  b5.set(0);
+  string s2 = b5.to_string<char, char_traits<char> >('c', 'd');
+  VERIFY( s2 == "ccccd" );
+
+  string s3 = b5.to_string<char, char_traits<char> >('d');
+  VERIFY( s3 == "dddd1" );
+
+  b5.set(2);
+  string s4 = b5.to_string<char>('e', 'f');
+  VERIFY( s4 == "eefef" );
+
+  string s5 = b5.to_string<char>('f');
+  VERIFY( s5 == "ff1f1" );
+
+  b5.set(4);
+  string s6 = b5.to_string('g', 'h');
+  VERIFY( s6 == "hghgh" );
+
+  string s7 = b5.to_string('h');
+  VERIFY( s7 == "1h1h1" );
+}
+
+int main()
+{
+  test01();
+  return 0;
+}