Re: PR 58148 patch

[François Dumont <frs dot dumont at gmail dot com>]

Sorry, I do not understand your remark Daniel.

So here is another proposal using sequence const_pointer as advised by 
Paolo. As we are now using it I consider that std::addressof was not 
necessary anymore on sequence elements and that sequence it was not 
necessary to check that sequence elements address can be passed through 
const_pointer. So the code is simpler.

Tested successfully under Linux x86_64.

Ok to commit ?

François


On 08/27/2013 10:48 PM, Daniel Krügler wrote:
> 2013/8/27 Paolo Carlini <paolo.carlini@oracle.com>:
> > On 08/27/2013 10:34 PM, François Dumont wrote:
> > >      As you seem to be more concern by the usage of experimental
> > > std::common_type than by the usage of const volatile void*I would like to
> > > propose the attached patch.
> > I don't think we should do that either. For example, if we are using
> > std::less & co to accommodate for segmented memory etc, I don't think we
> > should reduce all sorts of pointers to void* pointers, otherwise we could as
> > well use < & co. No, for 4.9.0 let's do something simple and safe.
> Wouldn't it solve the problem, if decltype(*it) is implicitly
> convertible to the value type? [I'm sorry, if I missed the essential
> context here]
>
> - Daniel

Index: include/debug/functions.h
===================================================================
--- include/debug/functions.h	(revision 201966)
+++ include/debug/functions.h	(working copy)
@@ -36,7 +36,7 @@
 #include <bits/move.h>                    // for __addressof and addressof
 #if __cplusplus >= 201103L
 # include <bits/stl_function.h>		  // for less and greater_equal
-# include <type_traits>			  // for common_type
+# include <type_traits>			  // for is_lvalue_reference and __and_
 #endif
 #include <debug/formatter.h>
 
@@ -172,27 +172,33 @@
     }
 
 #if __cplusplus >= 201103L
+  // Default implementation.
   template<typename _Iterator, typename _Sequence,
-	   typename _InputIterator,
-	   typename _PointerType1,
-	   typename _PointerType2>
+	   typename _InputIterator>
     inline bool
     __foreign_iterator_aux4(const _Safe_iterator<_Iterator, _Sequence>& __it,
 			    _InputIterator __other,
-			    _PointerType1, _PointerType2)
+			    typename _Sequence::const_pointer)
     {
-      typedef typename std::common_type<_PointerType1,
-					_PointerType2>::type _PointerType;
+      typedef typename _Sequence::const_pointer _PointerType;
       constexpr std::less<_PointerType> __l{};
       constexpr std::greater_equal<_PointerType> __ge{};
 
       return (__l(std::addressof(*__other),
-		  std::addressof(*(__it._M_get_sequence()->_M_base().begin())))
+		  &(*(__it._M_get_sequence()->_M_base().begin())))
 	      || __ge(std::addressof(*__other),
-		      std::addressof(*(__it._M_get_sequence()->_M_base().end()
-				       - 1)) + 1));
+		      &(*(__it._M_get_sequence()->_M_base().end() - 1)) + 1));
     }
-			  
+
+  // Fallback when address type cannot be implicitely casted to sequence
+  // const_pointer.
+  template<typename _Iterator, typename _Sequence,
+	   typename _InputIterator>
+    inline bool
+    __foreign_iterator_aux4(const _Safe_iterator<_Iterator, _Sequence>&,
+			    _InputIterator, ...)
+    { return true; }
+
   template<typename _Iterator, typename _Sequence, typename _InputIterator>
     inline bool
     __foreign_iterator_aux3(const _Safe_iterator<_Iterator, _Sequence>& __it,
@@ -208,10 +214,7 @@
 	if (std::addressof(*(__it._M_get_sequence()->_M_base().end() - 1))
 	    - std::addressof(*(__it._M_get_sequence()->_M_base().begin()))
 	    == __it._M_get_sequence()->size() - 1)
-	  return (__foreign_iterator_aux4
-		  (__it, __other,
-		   std::addressof(*(__it._M_get_sequence()->_M_base().begin())),
-		   std::addressof(*__other)));
+	  return __foreign_iterator_aux4(__it, __other, std::addressof(*__other));
       return true;
     }
 			   
@@ -223,7 +226,7 @@
 			    std::false_type)
     { return true; }
 #endif
-			   
+
   /** Checks that iterators do not belong to the same sequence. */
   template<typename _Iterator, typename _Sequence, typename _OtherIterator>
     inline bool
Index: testsuite/23_containers/vector/modifiers/insert/58148.cc
===================================================================
--- testsuite/23_containers/vector/modifiers/insert/58148.cc	(revision 0)
+++ testsuite/23_containers/vector/modifiers/insert/58148.cc	(revision 0)
@@ -0,0 +1,35 @@
+// 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/>.
+
+// { dg-options "-std=gnu++11" }
+// { dg-do compile }
+
+#include <vector>
+
+void
+test01()
+{
+  std::vector<wchar_t> v;
+  char c = 'a';
+  v.insert(v.begin(), &c, &c);
+}
+
+int main()
+{
+  test01();
+  return 0;
+}