public inbox for libstdc++-cvs@sourceware.org
help / color / mirror / Atom feed
* [gcc(refs/users/guojiufu/heads/personal-branch)] libstdc++: Define converting assignment operator for std::move_iterator
@ 2020-06-10 3:53 Jiu Fu Guo
0 siblings, 0 replies; only message in thread
From: Jiu Fu Guo @ 2020-06-10 3:53 UTC (permalink / raw)
To: gcc-cvs, libstdc++-cvs
https://gcc.gnu.org/g:733167f9d5ca5b9417559b7362d91e967be95a01
commit 733167f9d5ca5b9417559b7362d91e967be95a01
Author: Jonathan Wakely <jwakely@redhat.com>
Date: Tue Jun 9 22:16:24 2020 +0100
libstdc++: Define converting assignment operator for std::move_iterator
As clarified by LWG 3265, std::move_iterator is supposed to have an
assignment operator that converts from a different specialization of
std::move_iterator, which performs an assignment. That has always been
missing from libstdc++, so assigning a different type actually performs
a converting construction, then an assignment. This is non-conforming
for the (fairly contrived) case where the converting assignment is
well-formed but the converting construction is not.
* include/bits/stl_iterator.h (move_iterator::operator=): Define.
* testsuite/24_iterators/move_iterator/dr3265.cc: New test.
Diff:
---
libstdc++-v3/include/bits/stl_iterator.h | 8 ++++
.../testsuite/24_iterators/move_iterator/dr3265.cc | 51 ++++++++++++++++++++++
2 files changed, 59 insertions(+)
diff --git a/libstdc++-v3/include/bits/stl_iterator.h b/libstdc++-v3/include/bits/stl_iterator.h
index 72907813bf5..6d2d19eb068 100644
--- a/libstdc++-v3/include/bits/stl_iterator.h
+++ b/libstdc++-v3/include/bits/stl_iterator.h
@@ -1307,6 +1307,14 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
move_iterator(const move_iterator<_Iter>& __i)
: _M_current(__i.base()) { }
+ template<typename _Iter>
+ _GLIBCXX17_CONSTEXPR
+ move_iterator& operator=(const move_iterator<_Iter>& __i)
+ {
+ _M_current = __i.base();
+ return *this;
+ }
+
#if __cplusplus <= 201703L
_GLIBCXX17_CONSTEXPR iterator_type
base() const
diff --git a/libstdc++-v3/testsuite/24_iterators/move_iterator/dr3265.cc b/libstdc++-v3/testsuite/24_iterators/move_iterator/dr3265.cc
new file mode 100644
index 00000000000..05327e979ac
--- /dev/null
+++ b/libstdc++-v3/testsuite/24_iterators/move_iterator/dr3265.cc
@@ -0,0 +1,51 @@
+// Copyright (C) 2020 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 } }
+
+#include <iterator>
+
+struct Iter
+{
+ using iterator_category = std::forward_iterator_tag;
+ using value_type = int;
+ using pointer = int*;
+ using reference = int&;
+ using difference_type = std::ptrdiff_t;
+
+ Iter();
+
+ // Construction from int* is not valid:
+ Iter(int*) = delete;
+
+ // Assignment from int* is valid:
+ Iter& operator=(int*);
+
+ Iter& operator++();
+ Iter operator++(int);
+ int& operator*() const;
+ int* operator->() const;
+
+ template<int N> friend bool operator==(Iter, Iter);
+};
+
+void test01()
+{
+ std::move_iterator<Iter> m;
+ int i = 0;
+ m = std::make_move_iterator(&i); // Should use assignment not construction
+}
^ permalink raw reply [flat|nested] only message in thread
only message in thread, other threads:[~2020-06-10 3:53 UTC | newest]
Thread overview: (only message) (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-06-10 3:53 [gcc(refs/users/guojiufu/heads/personal-branch)] libstdc++: Define converting assignment operator for std::move_iterator Jiu Fu Guo
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).