PR libstdc++/89416 fix __is_move_insertable trait

The common base class for __is_move_insertable and __is_copy_insertable
instantiates both the copy and move tests, when only one is needed. The
unneeded one might cause errors outside the immediate context.

The solution used in this patch is to replace them with alias templates,
which will only be instantiated as needed.

	PR libstdc++/89416
	* include/bits/alloc_traits.h (__is_alloc_insertable_impl): Replace
	class template with class. Replace move and copy member types with
	member alias templates, so they are only instantiated when needed.
	(__is_copy_insertable, __is_move_insertable): Adjust base class.
	* testsuite/23_containers/vector/modifiers/push_back/89130.cc: Enable
	test for C++11/14/17 as well.
	* testsuite/23_containers/vector/modifiers/push_back/89416.cc: New
	test.

From-SVN: r269075

diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index bd38976a0f675f4a6355c45d6cff4a4cddab41b8..fab28f42079658f6906656b2c08b078c76a756b4 100644 (file)
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,15 @@
+2019-02-21  Jonathan Wakely  <jwakely@redhat.com>
+
+       PR libstdc++/89416
+       * include/bits/alloc_traits.h (__is_alloc_insertable_impl): Replace
+       class template with class. Replace move and copy member types with
+       member alias templates, so they are only instantiated when needed.
+       (__is_copy_insertable, __is_move_insertable): Adjust base class.
+       * testsuite/23_containers/vector/modifiers/push_back/89130.cc: Enable
+       test for C++11/14/17 as well.
+       * testsuite/23_containers/vector/modifiers/push_back/89416.cc: New
+       test.
+
 2019-02-20  Jakub Jelinek  <jakub@redhat.com>
 
        PR libstdc++/89402

diff --git a/libstdc++-v3/include/bits/alloc_traits.h b/libstdc++-v3/include/bits/alloc_traits.h
index 3b0c16fbf64e5bca974484a84c94272bbcff8c24..71892cbfaba12f7f2197966cb6b69583ebcba7d5 100644 (file)
--- a/libstdc++-v3/include/bits/alloc_traits.h
+++ b/libstdc++-v3/include/bits/alloc_traits.h
@@ -576,33 +576,32 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       __do_alloc_on_swap(__one, __two, __pocs());
     }
 
-  template<typename _Alloc>
-    class __is_alloc_insertable_impl
-    {
-      using _Traits = allocator_traits<_Alloc>;
-      using value_type = typename _Traits::value_type;
-
-      template<typename _Up, typename _Tp = __remove_cvref_t<_Up>,
-              typename
-              = decltype(_Traits::construct(std::declval<_Alloc&>(),
-                                            std::declval<_Tp*>(),
-                                            std::declval<_Up>()))>
-       static true_type
-       _M_select(int);
+  class __is_alloc_insertable_impl
+  {
+    template<typename _Alloc, typename _Up,
+            typename _Tp = __remove_cvref_t<_Up>,
+            typename = decltype(allocator_traits<_Alloc>::construct(
+                  std::declval<_Alloc&>(), std::declval<_Tp*>(),
+                  std::declval<_Up>()))>
+      static true_type
+      _M_select(int);
+
+    template<typename, typename>
+      static false_type
+      _M_select(...);
 
-      template<typename _Up>
-       static false_type
-       _M_select(...);
+  protected:
+    template<typename _Alloc, typename _Tp = typename _Alloc::value_type>
+      using copy = decltype(_M_select<_Alloc, const _Tp&>(0));
 
-    public:
-      using copy = decltype(_M_select<const value_type&>(0));
-      using move = decltype(_M_select<value_type>(0));
-    };
+    template<typename _Alloc, typename _Tp = typename _Alloc::value_type>
+      using move = decltype(_M_select<_Alloc, _Tp>(0));
+  };
 
   // true if _Alloc::value_type is CopyInsertable into containers using _Alloc
   template<typename _Alloc>
     struct __is_copy_insertable
-    : __is_alloc_insertable_impl<_Alloc>::copy
+    : __is_alloc_insertable_impl::template copy<_Alloc>
     { };
 
   // std::allocator<_Tp> just requires CopyConstructible
@@ -614,7 +613,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
   // true if _Alloc::value_type is MoveInsertable into containers using _Alloc
   template<typename _Alloc>
     struct __is_move_insertable
-    : __is_alloc_insertable_impl<_Alloc>::move
+    : __is_alloc_insertable_impl::template move<_Alloc>
     { };
 
   // std::allocator<_Tp> just requires MoveConstructible

diff --git a/libstdc++-v3/testsuite/23_containers/vector/modifiers/push_back/89130.cc b/libstdc++-v3/testsuite/23_containers/vector/modifiers/push_back/89130.cc
index 54b3f53069bcb654d15ac7e9b1e4530bb35d94a6..1a34f3e25d3adb82a1e24181305ee20901bb7d0d 100644 (file)
--- a/libstdc++-v3/testsuite/23_containers/vector/modifiers/push_back/89130.cc
+++ b/libstdc++-v3/testsuite/23_containers/vector/modifiers/push_back/89130.cc
@@ -15,8 +15,7 @@
 // with this library; see the file COPYING3.  If not see
 // <http://www.gnu.org/licenses/>.
 
-// { dg-options "-std=gnu++2a" }
-// { dg-do compile { target c++2a } }
+// { dg-do compile { target c++11 } }
 
 #include <vector>
 

diff --git a/libstdc++-v3/testsuite/23_containers/vector/modifiers/push_back/89416.cc b/libstdc++-v3/testsuite/23_containers/vector/modifiers/push_back/89416.cc
new file mode 100644 (file)
index 0000000..b107761
--- /dev/null
+++ b/libstdc++-v3/testsuite/23_containers/vector/modifiers/push_back/89416.cc
@@ -0,0 +1,44 @@
+// Copyright (C) 2019 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-do compile { target c++11 } }
+
+// PR libstdc++/89416
+
+#include <vector>
+
+template<typename T>
+  struct Alloc : std::allocator<T>
+  {
+    using std::allocator<T>::allocator;
+
+    template<typename U>
+      struct rebind { using other = Alloc<U>;  };
+  };
+
+struct X
+{
+  X(int);
+  X(X&&);
+};
+
+void test01()
+{
+  std::vector<X, Alloc<X>> V;
+  V.push_back(X(1));
+  V.emplace_back(1);
+}