From: Jonathan Wakely <jwakely@redhat.com>
To: "Daniel Krügler" <daniel.kruegler@gmail.com>
Cc: libstdc++ <libstdc++@gcc.gnu.org>, gcc-patches@gcc.gnu.org
Subject: Re: [PATCH] Implement LWG 2686, hash<error_condition>
Date: Tue, 07 May 2019 15:27:00 -0000 [thread overview]
Message-ID: <20190507152737.GW2599@redhat.com> (raw)
In-Reply-To: <20190504143628.GL2599@redhat.com>
[-- Attachment #1: Type: text/plain, Size: 2404 bytes --]
On 04/05/19 15:36 +0100, Jonathan Wakely wrote:
>On 03/05/19 23:42 +0100, Jonathan Wakely wrote:
>>On 23/03/17 17:49 +0000, Jonathan Wakely wrote:
>>>On 12/03/17 13:16 +0100, Daniel Krügler wrote:
>>>>The following is an *untested* patch suggestion, please verify.
>>>>
>>>>Notes: My interpretation is that hash<error_condition> should be
>>>>defined outside of the _GLIBCXX_COMPATIBILITY_CXX0X block, please
>>>>double-check that course of action.
>>>
>>>That's right.
>>>
>>>>I noticed that the preexisting hash<error_code> did directly refer to
>>>>the private members of error_code albeit those have public access
>>>>functions. For consistency I mimicked that existing style when
>>>>implementing hash<error_condition>.
>>>
>>>I see no reason for that, so I've removed the friend declaration and
>>>used the public member functions.
>>
>>I'm going to do the same for hash<error_code> too. It can also use the
>>public members instead of being a friend.
>>
>>
>>>Although this is a DR, I'm treating it as a new C++17 feature, so I've
>>>adjusted the patch to only add the new specialization for C++17 mode.
>>>We're too close to the GCC 7 release to be adding new things to the
>>>default mode, even minor things like this. After GCC 7 is released we
>>>can revisit it and decide if we want to enable it for all modes.
>>
>>We never revisited that, and it's still only enabled for C++17 and up.
>>I guess that's OK, but we could enabled it for C++11 and 14 on trunk
>>if we want. Anybody care enough to argue for that?
>>
>>>Here's what I've tested and will be committing.
>>>
>>>
>>
>>>commit 90ca0fd91f5c65af370beb20af06bdca257aaf63
>>>Author: Jonathan Wakely <jwakely@redhat.com>
>>>Date: Thu Mar 23 11:47:39 2017 +0000
>>>
>>> Implement LWG 2686, std::hash<error_condition>, for C++17
>>> 2017-03-23 Daniel Kruegler <daniel.kruegler@gmail.com>
>>> Implement LWG 2686, Why is std::hash specialized for error_code,
>>> but not error_condition?
>>> * include/std/system_error (hash<error_condition>): Define for C++17.
>>> * testsuite/20_util/hash/operators/size_t.cc (hash<error_condition>):
>>> Instantiate test for error_condition.
>>> * testsuite/20_util/hash/requirements/explicit_instantiation.cc
>>> (hash<error_condition>): Instantiate hash<error_condition>.
I'm adding a similar test for hash<error_code> too.
Tested powerpc64le-linux, committing to trunk shortly.
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commit 4034dddf0dbfc20ff9069602a419a95b09de20f6
Author: Jonathan Wakely <jwakely@redhat.com>
Date: Tue May 7 11:09:00 2019 +0100
Add test for std::hash<std::error_code>
Copied from 19_diagnostics/error_condition/hash.cc added recently.
* testsuite/19_diagnostics/error_code/hash.cc: New test.
diff --git a/libstdc++-v3/testsuite/19_diagnostics/error_code/hash.cc b/libstdc++-v3/testsuite/19_diagnostics/error_code/hash.cc
new file mode 100644
index 00000000000..2014e676878
--- /dev/null
+++ b/libstdc++-v3/testsuite/19_diagnostics/error_code/hash.cc
@@ -0,0 +1,50 @@
+// 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 run { target c++11 } }
+
+#include <system_error>
+#include <testsuite_hooks.h>
+
+struct error_cat : std::error_category
+{
+ error_cat(std::string s) : _name(s) { }
+ std::string _name;
+ const char* name() const noexcept override { return _name.c_str(); }
+ std::string message(int) const override { return "error"; }
+};
+
+void
+test01()
+{
+ std::hash<std::error_code> h;
+ error_cat kitty("kitty"), moggy("moggy");
+ std::error_code cond1(99, kitty);
+ VERIFY( h(cond1) == h(cond1) );
+ std::error_code cond2(99, kitty);
+ VERIFY( h(cond1) == h(cond2) );
+ std::error_code cond3(88, kitty);
+ VERIFY( h(cond1) != h(cond3) );
+ std::error_code cond4(99, moggy);
+ VERIFY( h(cond1) != h(cond4) );
+}
+
+int
+main()
+{
+ test01();
+}
prev parent reply other threads:[~2019-05-07 15:27 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-12 12:16 Daniel Krügler
2017-03-21 21:26 ` Daniel Krügler
2017-03-23 17:50 ` Jonathan Wakely
[not found] ` <20190503224255.GI2599@redhat.com>
2019-05-04 14:36 ` Jonathan Wakely
2019-05-07 9:06 ` Christophe Lyon
2019-05-07 9:37 ` Jonathan Wakely
2019-05-07 10:07 ` Jonathan Wakely
2019-05-07 12:22 ` Christophe Lyon
2019-05-09 14:43 ` Szabolcs Nagy
2019-05-09 15:17 ` Jonathan Wakely
2019-05-29 11:09 ` Szabolcs Nagy
2019-05-07 15:27 ` Jonathan Wakely [this message]
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