[PATCH] PR78052 Define std::allocator<void>::{construct,destroy}
Jonathan Wakely
jwakely@redhat.com
Thu Oct 20 10:13:00 GMT 2016
This let's std::allocator<void> be used in situations like:
std::allocate_shared<int>(std::allocator<void>(), 1);
where a "proto-allocator" is required. The other members such as
allocate() and max_size() don't make sense for void, but construct and
destroy don't depend on value_type.
PR libstdc++/78052
* include/bits/allocator.h (allocator<void>::construct)
(allocator<void>::destroy): Define.
* testsuite/20_util/allocator/void.cc: New test.
Tested x86_64-linux, committed to trunk. Also applying to gcc-5 and
gcc-6 branches, because this used to work before I put in the
allocator_traits<allocator<T>> partial specialization.
-------------- next part --------------
commit afbafc298dbed75375d0610e7e642e5cbf38d922
Author: Jonathan Wakely <jwakely@redhat.com>
Date: Thu Oct 20 03:40:21 2016 +0100
PR78052 Define std::allocator<void>::{construct,destroy}
PR libstdc++/78052
* include/bits/allocator.h (allocator<void>::construct)
(allocator<void>::destroy): Define.
* testsuite/20_util/allocator/void.cc: New test.
diff --git a/libstdc++-v3/include/bits/allocator.h b/libstdc++-v3/include/bits/allocator.h
index 8e78165..9fb5842 100644
--- a/libstdc++-v3/include/bits/allocator.h
+++ b/libstdc++-v3/include/bits/allocator.h
@@ -84,6 +84,15 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
typedef true_type propagate_on_container_move_assignment;
typedef true_type is_always_equal;
+
+ template<typename _Up, typename... _Args>
+ void
+ construct(_Up* __p, _Args&&... __args)
+ { ::new((void *)__p) _Up(std::forward<_Args>(__args)...); }
+
+ template<typename _Up>
+ void
+ destroy(_Up* __p) { __p->~_Up(); }
#endif
};
diff --git a/libstdc++-v3/testsuite/20_util/allocator/void.cc b/libstdc++-v3/testsuite/20_util/allocator/void.cc
new file mode 100644
index 0000000..0e47fef
--- /dev/null
+++ b/libstdc++-v3/testsuite/20_util/allocator/void.cc
@@ -0,0 +1,40 @@
+// Copyright (C) 2016 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 run { target c++11 } }
+
+#include <memory>
+#include <testsuite_hooks.h>
+
+template class std::allocator<void>;
+
+void
+test01()
+{
+ int i;
+ using alloc_type = std::allocator<void>;
+ alloc_type a;
+ std::allocator_traits<alloc_type>::construct(a, &i, 42);
+ VERIFY( i == 42 );
+ std::allocator_traits<alloc_type>::destroy(a, &i);
+}
+
+int
+main()
+{
+ test01();
+}
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