Improve relocation

2018-11-22  Marc Glisse  <marc.glisse@inria.fr>

	PR libstdc++/87106
	* include/bits/stl_algobase.h: Include <type_traits>.
	(__niter_base): Add noexcept specification.
	* include/bits/stl_deque.h: Include <bits/stl_uninitialized.h>.
	(__is_trivially_relocatable): Specialize for deque.
	* include/bits/stl_iterator.h: Include <type_traits>.
	(__niter_base): Add noexcept specification.
	* include/bits/stl_uninitialized.h (__is_trivially_relocatable):
	Add parameter for meta-programming.
	(__relocate_a_1, __relocate_a): Add noexcept specification.
	* include/bits/stl_vector.h (__use_relocate): Test __relocate_a.

From-SVN: r266386

6 files changed, 45 insertions, 9 deletions

diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index 267ec39..1e8072d 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,17 @@
+2018-11-22  Marc Glisse  <marc.glisse@inria.fr>
+
+	PR libstdc++/87106
+	* include/bits/stl_algobase.h: Include <type_traits>.
+	(__niter_base): Add noexcept specification.
+	* include/bits/stl_deque.h: Include <bits/stl_uninitialized.h>.
+	(__is_trivially_relocatable): Specialize for deque.
+	* include/bits/stl_iterator.h: Include <type_traits>.
+	(__niter_base): Add noexcept specification.
+	* include/bits/stl_uninitialized.h (__is_trivially_relocatable):
+	Add parameter for meta-programming.
+	(__relocate_a_1, __relocate_a): Add noexcept specification.
+	* include/bits/stl_vector.h (__use_relocate): Test __relocate_a.
+
 2018-11-22  Jonathan Wakely  <jwakely@redhat.com>
 
 	PR libstdc++/85930
diff --git a/libstdc++-v3/include/bits/stl_algobase.h b/libstdc++-v3/include/bits/stl_algobase.h
index b1ecd83..d1e1f67 100644
--- a/libstdc++-v3/include/bits/stl_algobase.h
+++ b/libstdc++-v3/include/bits/stl_algobase.h
@@ -69,6 +69,9 @@
 #include <debug/debug.h>
 #include <bits/move.h> // For std::swap
 #include <bits/predefined_ops.h>
+#if __cplusplus >= 201103L
+# include <type_traits>
+#endif
 
 namespace std _GLIBCXX_VISIBILITY(default)
 {
@@ -275,6 +278,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
   template<typename _Iterator>
     inline _Iterator
     __niter_base(_Iterator __it)
+    _GLIBCXX_NOEXCEPT_IF(std::is_nothrow_copy_constructible<_Iterator>::value)
     { return __it; }
 
   // Reverse the __niter_base transformation to get a
diff --git a/libstdc++-v3/include/bits/stl_deque.h b/libstdc++-v3/include/bits/stl_deque.h
index 555be16..5d1b428 100644
--- a/libstdc++-v3/include/bits/stl_deque.h
+++ b/libstdc++-v3/include/bits/stl_deque.h
@@ -61,6 +61,7 @@
 #include <bits/stl_iterator_base_funcs.h>
 #if __cplusplus >= 201103L
 #include <initializer_list>
+#include <bits/stl_uninitialized.h> // for __is_trivially_relocatable
 #endif
 
 #include <debug/assertions.h>
@@ -2366,6 +2367,15 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
 #undef _GLIBCXX_DEQUE_BUF_SIZE
 
 _GLIBCXX_END_NAMESPACE_CONTAINER
+
+#if __cplusplus >= 201103L
+  // std::allocator is safe, but it is not the only allocator
+  // for which this is valid.
+  template<class _Tp>
+    struct __is_trivially_relocatable<_GLIBCXX_STD_C::deque<_Tp>>
+    : true_type { };
+#endif
+
 _GLIBCXX_END_NAMESPACE_VERSION
 } // namespace std
 
diff --git a/libstdc++-v3/include/bits/stl_iterator.h b/libstdc++-v3/include/bits/stl_iterator.h
index d4a3e9e..1f0c081 100644
--- a/libstdc++-v3/include/bits/stl_iterator.h
+++ b/libstdc++-v3/include/bits/stl_iterator.h
@@ -65,6 +65,10 @@
 #include <bits/move.h>
 #include <bits/ptr_traits.h>
 
+#if __cplusplus >= 201103L
+# include <type_traits>
+#endif
+
 #if __cplusplus > 201402L
 # define __cpp_lib_array_constexpr 201603
 #endif
@@ -1004,6 +1008,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
   template<typename _Iterator, typename _Container>
     _Iterator
     __niter_base(__gnu_cxx::__normal_iterator<_Iterator, _Container> __it)
+    _GLIBCXX_NOEXCEPT_IF(std::is_nothrow_copy_constructible<_Iterator>::value)
     { return __it.base(); }
 
 #if __cplusplus >= 201103L
diff --git a/libstdc++-v3/include/bits/stl_uninitialized.h b/libstdc++-v3/include/bits/stl_uninitialized.h
index 8839bfd..cec0134 100644
--- a/libstdc++-v3/include/bits/stl_uninitialized.h
+++ b/libstdc++-v3/include/bits/stl_uninitialized.h
@@ -894,14 +894,14 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     }
 
   // This class may be specialized for specific types.
-  template<typename _Tp>
+  template<typename _Tp, typename = void>
     struct __is_trivially_relocatable
     : is_trivial<_Tp> { };
 
   template <typename _Tp, typename _Up>
     inline __enable_if_t<std::__is_trivially_relocatable<_Tp>::value, _Tp*>
     __relocate_a_1(_Tp* __first, _Tp* __last,
-		   _Tp* __result, allocator<_Up>& __alloc)
+		   _Tp* __result, allocator<_Up>& __alloc) noexcept
     {
       ptrdiff_t __count = __last - __first;
       if (__count > 0)
@@ -914,15 +914,15 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     inline _ForwardIterator
     __relocate_a_1(_InputIterator __first, _InputIterator __last,
 		   _ForwardIterator __result, _Allocator& __alloc)
+    noexcept(noexcept(std::__relocate_object_a(std::addressof(*__result),
+					       std::addressof(*__first),
+					       __alloc)))
     {
       typedef typename iterator_traits<_InputIterator>::value_type
 	_ValueType;
       typedef typename iterator_traits<_ForwardIterator>::value_type
 	_ValueType2;
       static_assert(std::is_same<_ValueType, _ValueType2>::value);
-      static_assert(noexcept(std::__relocate_object_a(std::addressof(*__result),
-						      std::addressof(*__first),
-						      __alloc)));
       _ForwardIterator __cur = __result;
       for (; __first != __last; ++__first, (void)++__cur)
 	std::__relocate_object_a(std::__addressof(*__cur),
@@ -935,6 +935,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     inline _ForwardIterator
     __relocate_a(_InputIterator __first, _InputIterator __last,
 		 _ForwardIterator __result, _Allocator& __alloc)
+    noexcept(noexcept(__relocate_a_1(std::__niter_base(__first),
+				     std::__niter_base(__last),
+				     std::__niter_base(__result), __alloc)))
     {
       return __relocate_a_1(std::__niter_base(__first),
 			    std::__niter_base(__last),
diff --git a/libstdc++-v3/include/bits/stl_vector.h b/libstdc++-v3/include/bits/stl_vector.h
index 05f9b7e..07dcd58 100644
--- a/libstdc++-v3/include/bits/stl_vector.h
+++ b/libstdc++-v3/include/bits/stl_vector.h
@@ -425,10 +425,10 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
     private:
 #if __cplusplus >= 201103L
       static constexpr bool __use_relocate =
-	noexcept(std::__relocate_object_a(
-			std::addressof(*std::declval<pointer>()),
-			std::addressof(*std::declval<pointer>()),
-			std::declval<_Tp_alloc_type&>()));
+	noexcept(std::__relocate_a(std::declval<pointer>(),
+				   std::declval<pointer>(),
+				   std::declval<pointer>(),
+				   std::declval<_Tp_alloc_type&>()));
 #endif
 
     protected: