From 5defb0f2085dc651c1d36539198da5d72fa09516 Mon Sep 17 00:00:00 2001
From: Paolo Carlini <paolo.carlini@oracle.com>
Date: Tue, 7 Oct 2008 14:49:20 +0000
Subject: [PATCH] stl_iterator.h (operator-(const reverse_iterator<>&, const
 reverse_iterator<>&), [...]): Use the auto -> return type syntax, implement
 DR 685.

2008-10-07  Paolo Carlini  <paolo.carlini@oracle.com>

	* include/bits/stl_iterator.h (operator-(const reverse_iterator<>&,
	const reverse_iterator<>&), operator-(const __normal_iterator<>&,
	const __normal_iterator<>&), operator-(const move_iterator<>&,
	const move_iterator<>&)): Use the auto -> return type syntax,
	implement DR 685.

From-SVN: r140937
---
 libstdc++-v3/ChangeLog                   |  8 ++++++++
 libstdc++-v3/include/bits/stl_iterator.h | 20 +++++++++++++++++++-
 2 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index 7ab200becd45..90c48823c933 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,11 @@
+2008-10-07  Paolo Carlini  <paolo.carlini@oracle.com>
+
+	* include/bits/stl_iterator.h (operator-(const reverse_iterator<>&,
+	const reverse_iterator<>&), operator-(const __normal_iterator<>&,
+	const __normal_iterator<>&), operator-(const move_iterator<>&,
+	const move_iterator<>&)): Use the auto -> return type syntax,
+	implement DR 685.
+
 2008-10-06  Jason Merrill  <jason@redhat.com>
 
 	* config/abi/pre/gnu.ver: Update char16/32_t manglings.
diff --git a/libstdc++-v3/include/bits/stl_iterator.h b/libstdc++-v3/include/bits/stl_iterator.h
index 0d66129fb801..d161e303e305 100644
--- a/libstdc++-v3/include/bits/stl_iterator.h
+++ b/libstdc++-v3/include/bits/stl_iterator.h
@@ -365,9 +365,17 @@ _GLIBCXX_BEGIN_NAMESPACE(std)
     { return !(__x < __y); }
 
   template<typename _IteratorL, typename _IteratorR>
+#ifdef __GXX_EXPERIMENTAL_CXX0X__
+    // DR 685.
+    inline auto
+    operator-(const reverse_iterator<_IteratorL>& __x,
+	      const reverse_iterator<_IteratorR>& __y)
+    -> decltype(__y.base() - __x.base())
+#else
     inline typename reverse_iterator<_IteratorL>::difference_type
     operator-(const reverse_iterator<_IteratorL>& __x,
 	      const reverse_iterator<_IteratorR>& __y)
+#endif
     { return __y.base() - __x.base(); }
   //@}
 
@@ -835,9 +843,17 @@ _GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx)
   // operators but also operator- must accept mixed iterator/const_iterator
   // parameters.
   template<typename _IteratorL, typename _IteratorR, typename _Container>
+#ifdef __GXX_EXPERIMENTAL_CXX0X__
+    // DR 685.
+    inline auto
+    operator-(const __normal_iterator<_IteratorL, _Container>& __lhs,
+	      const __normal_iterator<_IteratorR, _Container>& __rhs)
+    -> decltype(__lhs.base() - __rhs.base())
+#else
     inline typename __normal_iterator<_IteratorL, _Container>::difference_type
     operator-(const __normal_iterator<_IteratorL, _Container>& __lhs,
 	      const __normal_iterator<_IteratorR, _Container>& __rhs)
+#endif
     { return __lhs.base() - __rhs.base(); }
 
   template<typename _Iterator, typename _Container>
@@ -1001,10 +1017,12 @@ _GLIBCXX_BEGIN_NAMESPACE(std)
 	       const move_iterator<_IteratorR>& __y)
     { return !(__x < __y); }
 
+  // DR 685.
   template<typename _IteratorL, typename _IteratorR>
-    inline typename move_iterator<_IteratorL>::difference_type
+    inline auto
     operator-(const move_iterator<_IteratorL>& __x,
 	      const move_iterator<_IteratorR>& __y)
+    -> decltype(__x.base() - __y.base())
     { return __x.base() - __y.base(); }
 
   template<typename _Iterator>
-- 
2.47.3