* [patch] Fix libstdc++/56112, inserting non-pairs into std::unordered_map
@ 2013-01-28 2:02 Jonathan Wakely
0 siblings, 0 replies; only message in thread
From: Jonathan Wakely @ 2013-01-28 2:02 UTC (permalink / raw)
To: libstdc++, gcc-patches
[-- Attachment #1: Type: text/plain, Size: 661 bytes --]
This is a much simpler fix than discussed in bugzilla, just forward to
_M_emplace() when inserting from a type that needs conversion to
value_type. This also fixes the dangling reference problem as well as
the regression with calling insert() with convertible types.
PR libstdc++/56112
* include/bits/hashtable_policy.h (insert(_Pair&&)): Use _M_emplace
to construct value_type explicitly before trying to extract the key.
* testsuite/23_containers/unordered_map/cons/56112.cc: New.
Tested x86_64-linux, will commit to trunk tomorrow.
N.B. The dangling reference bug is present on the 4.6 and 4.7
branches, but not a regression.
[-- Attachment #2: patch.txt --]
[-- Type: text/plain, Size: 2649 bytes --]
commit ca741fccc5d052db08ba839bd45ece7564ac5004
Author: Jonathan Wakely <jwakely.gcc@gmail.com>
Date: Mon Jan 28 00:08:43 2013 +0000
PR libstdc++/56112
* include/bits/hashtable_policy.h (insert(_Pair&&)): Use _M_emplace
to construct value_type explicitly before trying to extract the key.
* testsuite/23_containers/unordered_map/cons/56112.cc: New.
diff --git a/libstdc++-v3/include/bits/hashtable_policy.h b/libstdc++-v3/include/bits/hashtable_policy.h
index 023f46d..1ade3f9 100644
--- a/libstdc++-v3/include/bits/hashtable_policy.h
+++ b/libstdc++-v3/include/bits/hashtable_policy.h
@@ -836,7 +836,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
insert(_Pair&& __v)
{
__hashtable& __h = this->_M_conjure_hashtable();
- return __h._M_insert(std::forward<_Pair>(__v), __unique_keys());
+ return __h._M_emplace(__unique_keys(), std::forward<_Pair>(__v));
}
template<typename _Pair, typename = _IFconsp<_Pair>>
diff --git a/libstdc++-v3/testsuite/23_containers/unordered_map/cons/56112.cc b/libstdc++-v3/testsuite/23_containers/unordered_map/cons/56112.cc
new file mode 100644
index 0000000..c297ef7
--- /dev/null
+++ b/libstdc++-v3/testsuite/23_containers/unordered_map/cons/56112.cc
@@ -0,0 +1,49 @@
+// { dg-options "-std=gnu++0x" }
+
+// Copyright (C) 2013 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/>.
+
+#include <unordered_map>
+#include <utility>
+
+struct Key
+{
+ explicit Key(const int* p) : value(p) { }
+ ~Key() { value = nullptr; }
+
+ bool operator==(const Key& k) const { return *value == *k.value; }
+
+ const int* value;
+};
+
+struct hash
+{
+ std::size_t operator()(const Key& k) const noexcept { return *k.value; }
+};
+
+struct S
+{
+ int value;
+ operator std::pair<const Key, int>() const { return {Key(&value), value}; }
+};
+
+int main()
+{
+ S s[1] = { {2} };
+ std::unordered_map<Key, int, hash> m(s, s+1);
+ std::unordered_multimap<Key, int, hash> mm(s, s+1);
+}
^ permalink raw reply [flat|nested] only message in thread
only message in thread, other threads:[~2013-01-28 2:02 UTC | newest]
Thread overview: (only message) (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2013-01-28 2:02 [patch] Fix libstdc++/56112, inserting non-pairs into std::unordered_map Jonathan Wakely
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).