stl_algobase.h (__niter_wrap): New.

2018-07-03  François Dumont  <fdumont@gcc.gnu.org>

	* include/bits/stl_algobase.h (__niter_wrap): New.
	(__copy_move_a2(_II, _II, _OI)): Use latter.
	(__copy_move_backward_a2(_BI1, _BI1, _BI2)): Likewise.
	(fill_n(_OI, _Size, const _Tp&)): Likewise.
	(equal(_II1, _II1, _II2)): Use __glibcxx_requires_can_increment.
	* include/debug/stl_iterator.h
	(std::__niter_base(const __gnu_cxx::_Safe_iterator<
	__gnu_cxx::__normal_iterator<>, _Sequence>&)): New declaration.
	* include/debug/vector (__niter_base(const __gnu_cxx::_Safe_iterator<
	__gnu_cxx::__normal_iterator<>, _Sequence>&)): New.

From-SVN: r262349

4 files changed, 56 insertions, 6 deletions

diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index ae734e8..838887c 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,16 @@
+2018-07-03  François Dumont  <fdumont@gcc.gnu.org>
+
+	* include/bits/stl_algobase.h (__niter_wrap): New.
+	(__copy_move_a2(_II, _II, _OI)): Use latter.
+	(__copy_move_backward_a2(_BI1, _BI1, _BI2)): Likewise.
+	(fill_n(_OI, _Size, const _Tp&)): Likewise.
+	(equal(_II1, _II1, _II2)): Use __glibcxx_requires_can_increment.
+	* include/debug/stl_iterator.h
+	(std::__niter_base(const __gnu_cxx::_Safe_iterator<
+	__gnu_cxx::__normal_iterator<>, _Sequence>&)): New declaration.
+	* include/debug/vector (__niter_base(const __gnu_cxx::_Safe_iterator<
+	__gnu_cxx::__normal_iterator<>, _Sequence>&)): New.
+
 2018-07-02  Jonathan Wakely  <jwakely@redhat.com>
 
 	P0758R1 Implicit conversion traits
diff --git a/libstdc++-v3/include/bits/stl_algobase.h b/libstdc++-v3/include/bits/stl_algobase.h
index 022a3f1..16a3f83 100644
--- a/libstdc++-v3/include/bits/stl_algobase.h
+++ b/libstdc++-v3/include/bits/stl_algobase.h
@@ -277,6 +277,20 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     __niter_base(_Iterator __it)
     { return __it; }
 
+  // Reverse the __niter_base transformation to get a
+  // __normal_iterator back again (this assumes that __normal_iterator
+  // is only used to wrap random access iterators, like pointers).
+  template<typename _From, typename _To>
+    inline _From
+    __niter_wrap(_From __from, _To __res)
+    { return __from + (__res - std::__niter_base(__from)); }
+
+  // No need to wrap, iterator already has the right type.
+  template<typename _Iterator>
+    inline _Iterator
+    __niter_wrap(_Iterator, _Iterator __res)
+    { return __res; }
+
   // All of these auxiliary structs serve two purposes.  (1) Replace
   // calls to copy with memmove whenever possible.  (Memmove, not memcpy,
   // because the input and output ranges are permitted to overlap.)
@@ -419,9 +433,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     inline _OI
     __copy_move_a2(_II __first, _II __last, _OI __result)
     {
-      return _OI(std::__copy_move_a<_IsMove>(std::__niter_base(__first),
-					     std::__niter_base(__last),
-					     std::__niter_base(__result)));
+      return std::__niter_wrap(__result,
+		std::__copy_move_a<_IsMove>(std::__niter_base(__first),
+					    std::__niter_base(__last),
+					    std::__niter_base(__result)));
     }
 
   /**
@@ -593,7 +608,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     inline _BI2
     __copy_move_backward_a2(_BI1 __first, _BI1 __last, _BI2 __result)
     {
-      return _BI2(std::__copy_move_backward_a<_IsMove>
+      return std::__niter_wrap(__result,
+		std::__copy_move_backward_a<_IsMove>
 		  (std::__niter_base(__first), std::__niter_base(__last),
 		   std::__niter_base(__result)));
     }
@@ -785,7 +801,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       __glibcxx_function_requires(_OutputIteratorConcept<_OI, _Tp>)
       __glibcxx_requires_can_increment(__first, __n);
 
-      return _OI(std::__fill_n_a(std::__niter_base(__first), __n, __value));
+      return std::__niter_wrap(__first,
+		std::__fill_n_a(std::__niter_base(__first), __n, __value));
     }
 
   template<bool _BoolType>
@@ -1043,7 +1060,7 @@ _GLIBCXX_BEGIN_NAMESPACE_ALGO
       __glibcxx_function_requires(_EqualOpConcept<
 	    typename iterator_traits<_II1>::value_type,
 	    typename iterator_traits<_II2>::value_type>)
-      __glibcxx_requires_valid_range(__first1, __last1);
+      __glibcxx_requires_can_increment_range(__first1, __last1, __first2);
 
       return std::__equal_aux(std::__niter_base(__first1),
 			      std::__niter_base(__last1),
diff --git a/libstdc++-v3/include/debug/stl_iterator.h b/libstdc++-v3/include/debug/stl_iterator.h
index a6a2a76..f20b000 100644
--- a/libstdc++-v3/include/debug/stl_iterator.h
+++ b/libstdc++-v3/include/debug/stl_iterator.h
@@ -120,4 +120,17 @@ namespace __gnu_debug
 #endif
 }
 
+namespace std
+{
+_GLIBCXX_BEGIN_NAMESPACE_VERSION
+
+  template<typename _Iterator, typename _Container, typename _Sequence>
+    _Iterator
+    __niter_base(const __gnu_debug::_Safe_iterator<
+		 __gnu_cxx::__normal_iterator<_Iterator, _Container>,
+		 _Sequence>&);
+
+_GLIBCXX_END_NAMESPACE_VERSION
+}
+
 #endif
diff --git a/libstdc++-v3/include/debug/vector b/libstdc++-v3/include/debug/vector
index 802f4fd..ced5520 100644
--- a/libstdc++-v3/include/debug/vector
+++ b/libstdc++-v3/include/debug/vector
@@ -785,6 +785,13 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       { return std::hash<_GLIBCXX_STD_C::vector<bool, _Alloc>>()(__b); }
     };
 
+ template<typename _Iterator, typename _Container, typename _Sequence>
+    _Iterator
+    __niter_base(const __gnu_debug::_Safe_iterator<
+		 __gnu_cxx::__normal_iterator<_Iterator, _Container>,
+		 _Sequence>& __it)
+    { return std::__niter_base(__it.base()); }
+
 _GLIBCXX_END_NAMESPACE_VERSION
 #endif