Patchwork [v3] libstdc++/57704

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Submitter Paolo Carlini
Date June 24, 2013, 11:17 p.m.
Message ID <51C8D3A6.80104@oracle.com>
Download mbox | patch
Permalink /patch/253991/
State New
Headers show

Comments

Paolo Carlini - June 24, 2013, 11:17 p.m.
Hi,

this is the LWG 467 bit about char_traits<char>::lt: since the member is 
not used elsewhere in the library as an implementation detail and the 
symbol is not exported, I think we can just unconditionally apply the 
tweak and be done.

Tested x86_64-linux.

Thanks,
Paolo.

/////////////////////////
2013-06-24  Paolo Carlini  <paolo.carlini@oracle.com>

	PR libstdc++/57704
	* include/bits/char_traits.h (char_traits<char>::lt): Implement
	LWG 467.
	* testsuite/21_strings/char_traits/requirements/char/57704.cc: New.

Patch

Index: include/bits/char_traits.h
===================================================================
--- include/bits/char_traits.h	(revision 200380)
+++ include/bits/char_traits.h	(working copy)
@@ -248,7 +248,11 @@ 
 
       static _GLIBCXX_CONSTEXPR bool
       lt(const char_type& __c1, const char_type& __c2) _GLIBCXX_NOEXCEPT
-      { return __c1 < __c2; }
+      {
+	// LWG 467.
+	return (static_cast<unsigned char>(__c1)
+		< static_cast<unsigned char>(__c2));
+      }
 
       static int
       compare(const char_type* __s1, const char_type* __s2, size_t __n)
Index: testsuite/21_strings/char_traits/requirements/char/57704.cc
===================================================================
--- testsuite/21_strings/char_traits/requirements/char/57704.cc	(revision 0)
+++ testsuite/21_strings/char_traits/requirements/char/57704.cc	(working copy)
@@ -0,0 +1,37 @@ 
+// 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/>.
+
+#include <string>
+#include <testsuite_hooks.h>
+
+void test01()
+{
+  bool test __attribute__((unused)) = true;
+
+  char a = '\x7f';
+  char b = '\x80';
+
+  VERIFY( (std::char_traits<char>::lt(a, b)
+	   == (static_cast<unsigned char>(a)
+	       < static_cast<unsigned char>(b))) );
+}
+
+int main()
+{
+  test01();
+  return 0;
+}