Re: [Bug libstdc++/63500] [4.9/5 Regression] bug in debug version of std::make_move_iterator?

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

On 15/10/2014 13:10, Jonathan Wakely wrote:
> I find this much easier to read:
>
> #if __cplusplus < 201103L
>      typedef _Is_contiguous_sequence<_Sequence> __tag;
> #else
>      using __lvalref = std::is_lvalue_reference<
>        typename std::iterator_traits<_InputIterator>::reference>;
>      using __contiguous = _Is_contiguous_sequence<_Sequence>;
>      using __tag = typename std::conditional<__lvalref::value, 
> __contiguous,
> std::__false_type>::type;
> #endif
>      return __foreign_iterator_aux3(__it, __other, __other_end, __tag());
>
> It only has one preprocessor condition and it avoids mismatched
> parentheses caused by opening the function parameter list once but
> closing it twice in two different branches.
That's much better indeed.

    Shall we go with this ? Of course we are simply considering that we 
can't check for foreign iterators when some iterator adapters comes 
in-between. I hope one day to detect invalid usages even in this context.

2014-10-16  François Dumont  <fdumont@gcc.gnu.org>

    PR libstdc++/63500
    * include/debug/functions.h (__foreign_iterator_aux2): Do not check for
    foreign iterators if input iterators returns rvalue reference.
    * testsuite/23_containers/vector/63500.cc: New.

François

Index: include/debug/functions.h
===================================================================
--- include/debug/functions.h	(revision 216279)
+++ include/debug/functions.h	(working copy)
@@ -34,7 +34,7 @@
 					  // _Iter_base
 #include <bits/cpp_type_traits.h>	  // for __is_integer
 #include <bits/move.h>                    // for __addressof and addressof
-# include <bits/stl_function.h>		  // for less
+#include <bits/stl_function.h>		  // for less
 #if __cplusplus >= 201103L
 # include <type_traits>			  // for is_lvalue_reference and __and_
 #endif
@@ -252,8 +252,16 @@
 			    const _InputIterator& __other,
 			    const _InputIterator& __other_end)
     {
-      return __foreign_iterator_aux3(__it, __other, __other_end,
-				     _Is_contiguous_sequence<_Sequence>());
+#if __cplusplus < 201103L
+      typedef _Is_contiguous_sequence<_Sequence> __tag;
+#else
+      using __lvalref = std::is_lvalue_reference<
+	typename std::iterator_traits<_InputIterator>::reference>;
+      using __contiguous = _Is_contiguous_sequence<_Sequence>;
+      using __tag = typename std::conditional<__lvalref::value, __contiguous,
+					      std::__false_type>::type;
+#endif
+      return __foreign_iterator_aux3(__it, __other, __other_end, __tag());
     }
 
   /* Handle the case where we aren't really inserting a range after all */
Index: testsuite/23_containers/vector/63500.cc
===================================================================
--- testsuite/23_containers/vector/63500.cc	(revision 0)
+++ testsuite/23_containers/vector/63500.cc	(working copy)
@@ -0,0 +1,39 @@
+// -*- C++ -*-
+
+// Copyright (C) 2014 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 <memory>
+#include <iterator>
+#include <debug/vector>
+
+class Foo
+{};
+
+void
+test01()
+{
+  __gnu_debug::vector<std::unique_ptr<Foo>> v;
+  __gnu_debug::vector<std::unique_ptr<Foo>> w;
+
+  v.insert(end(v),
+	   make_move_iterator(begin(w)),
+	   make_move_iterator(end(w)));
+}