From: paolo <paolo@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Thu, 27 May 2010 17:37:11 +0000 (+0000)
Subject: 2010-05-27  Paolo Carlini  <paolo.carlini@oracle.com>
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=53f9e3d0527049aabbf66901f55e091f7ddc0401;p=thirdparty%2Fgcc.git

2010-05-27  Paolo Carlini  <paolo.carlini@oracle.com>

	PR libstdc++/40497
	* include/bits/cpp_type_traits.h (__is_iterator): Add.
	* include/bits/stl_iterator_base_funcs.h (next, prev): Use it.
	* testsuite/24_iterators/operations/40497.cc: New.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@159933 138bc75d-0d04-0410-961f-82ee72b054a4
---

diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index 82d13dafd642..0af8ae6c7303 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,10 @@
+2010-05-27  Paolo Carlini  <paolo.carlini@oracle.com>
+
+	PR libstdc++/40497
+	* include/bits/cpp_type_traits.h (__is_iterator): Add.
+	* include/bits/stl_iterator_base_funcs.h (next, prev): Use it.
+	* testsuite/24_iterators/operations/40497.cc: New.
+
 2010-05-21  Paolo Carlini  <paolo.carlini@oracle.com>
 
 	PR libstdc++/25306
diff --git a/libstdc++-v3/include/bits/cpp_type_traits.h b/libstdc++-v3/include/bits/cpp_type_traits.h
index 0d7b9ff09fcd..8c5d8e9ca279 100644
--- a/libstdc++-v3/include/bits/cpp_type_traits.h
+++ b/libstdc++-v3/include/bits/cpp_type_traits.h
@@ -414,6 +414,34 @@ _GLIBCXX_BEGIN_NAMESPACE(std)
     };
 #endif
 
+  template<typename _Tp>
+    class __is_iterator_helper
+    {
+      typedef char __one;
+      typedef struct { char __arr[2]; } __two;
+
+      template<typename _Up>
+        struct _Wrap_type
+	{ };
+
+      template<typename _Up>
+        static __one __test(_Wrap_type<typename _Up::iterator_category>*);
+
+      template<typename _Up>
+        static __two __test(...);
+
+    public:
+      static const bool __value = (sizeof(__test<_Tp>(0)) == 1
+				   || __is_pointer<_Tp>::__value);
+    };
+
+  template<typename _Tp>
+    struct __is_iterator
+    {
+      enum { __value = __is_iterator_helper<_Tp>::__value };
+      typedef typename __truth_type<__value>::__type __type;
+    };
+
 _GLIBCXX_END_NAMESPACE
 
 #endif //_CPP_TYPE_TRAITS_H
diff --git a/libstdc++-v3/include/bits/stl_iterator_base_funcs.h b/libstdc++-v3/include/bits/stl_iterator_base_funcs.h
index 627fbe917eed..50e0bca83e28 100644
--- a/libstdc++-v3/include/bits/stl_iterator_base_funcs.h
+++ b/libstdc++-v3/include/bits/stl_iterator_base_funcs.h
@@ -61,6 +61,7 @@
 #define _STL_ITERATOR_BASE_FUNCS_H 1
 
 #pragma GCC system_header
+
 #include <bits/concept_check.h>
 
 _GLIBCXX_BEGIN_NAMESPACE(std)
@@ -172,9 +173,18 @@ _GLIBCXX_BEGIN_NAMESPACE(std)
       std::__advance(__i, __d, std::__iterator_category(__i));
     }
 
+_GLIBCXX_END_NAMESPACE
+
 #ifdef __GXX_EXPERIMENTAL_CXX0X__
+
+#include <ext/type_traits.h> // For __enable_if and __is_iterator
+
+_GLIBCXX_BEGIN_NAMESPACE(std)
+
   template<typename _ForwardIterator>
-    inline _ForwardIterator
+    inline typename
+    __gnu_cxx::__enable_if<__is_iterator<_ForwardIterator>::__value,
+			   _ForwardIterator>::__type
     next(_ForwardIterator __x, typename
 	 iterator_traits<_ForwardIterator>::difference_type __n = 1)
     {
@@ -183,15 +193,18 @@ _GLIBCXX_BEGIN_NAMESPACE(std)
     }
 
   template<typename _BidirectionalIterator>
-    inline _BidirectionalIterator 
+    inline typename
+    __gnu_cxx::__enable_if<__is_iterator<_BidirectionalIterator>::__value,
+			   _BidirectionalIterator>::__type
     prev(_BidirectionalIterator __x, typename
 	 iterator_traits<_BidirectionalIterator>::difference_type __n = 1) 
     {
       std::advance(__x, -__n);
       return __x;
     }
-#endif
 
 _GLIBCXX_END_NAMESPACE
 
+#endif // __GXX_EXPERIMENTAL_CXX0X__
+
 #endif /* _STL_ITERATOR_BASE_FUNCS_H */
diff --git a/libstdc++-v3/testsuite/24_iterators/operations/40497.cc b/libstdc++-v3/testsuite/24_iterators/operations/40497.cc
new file mode 100644
index 000000000000..59a64fbb0992
--- /dev/null
+++ b/libstdc++-v3/testsuite/24_iterators/operations/40497.cc
@@ -0,0 +1,41 @@
+// { dg-options "-std=gnu++0x" }
+// { dg-do compile }
+
+// Copyright (C) 2010 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/>.
+
+namespace X
+{
+  class C { };
+
+  template<class T> void next(T) { }
+  template<class T> void prev(T) { }
+}
+
+using namespace X;
+
+#include <iterator>
+
+using namespace std;
+
+// libstdc++/40497
+void test01()
+{
+  C c;
+  next(c);
+  prev(c);
+}