[gcc/devel/gccgo] libstdc++: Add missing bits of P0896R4 pertaining to [back|front]_insert_iterator
Ian Lance Taylor
ian@gcc.gnu.org
Sat Apr 4 21:23:37 GMT 2020
https://gcc.gnu.org/g:85c143d002a31bebb675161315c8e62db240b636
commit 85c143d002a31bebb675161315c8e62db240b636
Author: Patrick Palka <ppalka@redhat.com>
Date: Mon Feb 24 07:59:08 2020 -0500
libstdc++: Add missing bits of P0896R4 pertaining to [back|front]_insert_iterator
This adds some missing pieces of the Ranges TS that make back_insert_iterator and
front_insert_iterator conform to the new output_iterator requirements.
It also fixes a bug in ranges::__copy_or_move and
ranges::__copy_or_move_backward in which we were inspecting the iter_value_t of
the output iterator, but output iterators such as back_insert_iterator and
front_insert_iterator whose value_type = void do not have an iter_value_t
according to [readable.traits] p4. The entire __use_memmove condition should
probably be rewritten, but the simplest fix for now is to inspect the
iterator_traits of the output iterator instead.
libstdc++-v3/ChangeLog:
PR libstdc++/93884
* include/bits/ranges_algobase.h (__copy_or_move,
__copy_or_move_backward): Don't inspect the iter_value_t of the output
iterator, instead inspect its iterator_traits directly.
* include/bits/stl_iterator.h (back_insert_iterator::container):
Conditionally initialize.
(back_insert_iterator::difference_type): Conditionally define.
(back_insert_iterator::back_insert_iterator): Conditionally define this
default constructor.
(front_insert_iterator::container): Conditionally initialize.
(front_insert_iterator::difference_type): Conditionally define.
(front_insert_iterator::front_insert_iterator): Conditionally define
this default constructor.
* 24_iterators/back_insert_iterator/pr93884.cc: New test.
* 24_iterators/front_insert_iterator/pr93884.cc: New test.
Diff:
---
libstdc++-v3/ChangeLog | 16 ++++++++
libstdc++-v3/include/bits/ranges_algobase.h | 4 +-
libstdc++-v3/include/bits/stl_iterator.h | 22 +++++++++++
.../24_iterators/back_insert_iterator/pr93884.cc | 44 ++++++++++++++++++++++
.../24_iterators/front_insert_iterator/pr93884.cc | 44 ++++++++++++++++++++++
5 files changed, 128 insertions(+), 2 deletions(-)
diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index 9996c1955d0..5da5c22775c 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,5 +1,21 @@
2020-02-24 Patrick Palka <ppalka@redhat.com>
+ PR libstdc++/93884
+ * include/bits/ranges_algobase.h (__copy_or_move,
+ __copy_or_move_backward): Don't inspect the iter_value_t of the output
+ iterator, instead inspect its iterator_traits directly.
+ * include/bits/stl_iterator.h (back_insert_iterator::container):
+ Conditionally initialize.
+ (back_insert_iterator::difference_type): Conditionally define.
+ (back_insert_iterator::back_insert_iterator): Conditionally define this
+ default constructor.
+ (front_insert_iterator::container): Conditionally initialize.
+ (front_insert_iterator::difference_type): Conditionally define.
+ (front_insert_iterator::front_insert_iterator): Conditionally define
+ this default constructor.
+ * 24_iterators/back_insert_iterator/pr93884.cc: New test.
+ * 24_iterators/front_insert_iterator/pr93884.cc: New test.
+
P0769R2 Add shift to <algorithm>
* include/bits/ranges_algo.h (shift_left, shift_right): New.
* testsuite/25_algorithms/shift_left/1.cc: New test.
diff --git a/libstdc++-v3/include/bits/ranges_algobase.h b/libstdc++-v3/include/bits/ranges_algobase.h
index 807822e99c8..73f0205ba7f 100644
--- a/libstdc++-v3/include/bits/ranges_algobase.h
+++ b/libstdc++-v3/include/bits/ranges_algobase.h
@@ -249,7 +249,7 @@ namespace ranges
else if constexpr (sized_sentinel_for<_Sent, _Iter>)
{
using _ValueTypeI = iter_value_t<_Iter>;
- using _ValueTypeO = iter_value_t<_Out>;
+ using _ValueTypeO = typename iterator_traits<_Out>::value_type;
constexpr bool __use_memmove
= (is_trivially_copyable_v<_ValueTypeI>
&& is_same_v<_ValueTypeI, _ValueTypeO>
@@ -386,7 +386,7 @@ namespace ranges
else if constexpr (sized_sentinel_for<_Sent, _Iter>)
{
using _ValueTypeI = iter_value_t<_Iter>;
- using _ValueTypeO = iter_value_t<_Out>;
+ using _ValueTypeO = typename iterator_traits<_Out>::value_type;
constexpr bool __use_memmove
= (is_trivially_copyable_v<_ValueTypeI>
&& is_same_v<_ValueTypeI, _ValueTypeO>
diff --git a/libstdc++-v3/include/bits/stl_iterator.h b/libstdc++-v3/include/bits/stl_iterator.h
index 372df223113..caaa8c483b8 100644
--- a/libstdc++-v3/include/bits/stl_iterator.h
+++ b/libstdc++-v3/include/bits/stl_iterator.h
@@ -496,11 +496,22 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
: public iterator<output_iterator_tag, void, void, void, void>
{
protected:
+#if __cplusplus <= 201703L
_Container* container;
+#else
+ _Container* container = nullptr;
+#endif
public:
/// A nested typedef for the type of whatever container you used.
typedef _Container container_type;
+#if __cplusplus > 201703L
+ using difference_type = ptrdiff_t;
+#endif
+
+#if __cplusplus > 201703L
+ constexpr back_insert_iterator() noexcept = default;
+#endif
/// The only way to create this %iterator is with a container.
explicit
@@ -588,11 +599,22 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
: public iterator<output_iterator_tag, void, void, void, void>
{
protected:
+#if __cplusplus <= 201703L
_Container* container;
+#else
+ _Container* container = nullptr;
+#endif
public:
/// A nested typedef for the type of whatever container you used.
typedef _Container container_type;
+#if __cplusplus > 201703L
+ using difference_type = ptrdiff_t;
+#endif
+
+#if __cplusplus > 201703L
+ constexpr front_insert_iterator() noexcept = default;
+#endif
/// The only way to create this %iterator is with a container.
explicit front_insert_iterator(_Container& __x)
diff --git a/libstdc++-v3/testsuite/24_iterators/back_insert_iterator/pr93884.cc b/libstdc++-v3/testsuite/24_iterators/back_insert_iterator/pr93884.cc
new file mode 100644
index 00000000000..5a6287ddd40
--- /dev/null
+++ b/libstdc++-v3/testsuite/24_iterators/back_insert_iterator/pr93884.cc
@@ -0,0 +1,44 @@
+// 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-options "-std=gnu++2a" }
+// { dg-do run { target c++2a } }
+
+#include <iterator>
+#include <algorithm>
+#include <vector>
+#include <testsuite_hooks.h>
+
+namespace ranges = std::ranges;
+namespace views = std::views;
+
+void
+test01()
+{
+ auto v = std::vector<int>{};
+ auto i = views::iota(0, 10);
+ auto o = std::back_inserter(v);
+ static_assert(std::output_iterator<decltype(o), int>);
+ ranges::copy(i, o);
+ VERIFY( ranges::equal(v, i) );
+}
+
+int
+main()
+{
+ test01();
+}
diff --git a/libstdc++-v3/testsuite/24_iterators/front_insert_iterator/pr93884.cc b/libstdc++-v3/testsuite/24_iterators/front_insert_iterator/pr93884.cc
new file mode 100644
index 00000000000..eaf4e9a187f
--- /dev/null
+++ b/libstdc++-v3/testsuite/24_iterators/front_insert_iterator/pr93884.cc
@@ -0,0 +1,44 @@
+// 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-options "-std=gnu++2a" }
+// { dg-do run { target c++2a } }
+
+#include <iterator>
+#include <algorithm>
+#include <deque>
+#include <testsuite_hooks.h>
+
+namespace ranges = std::ranges;
+namespace views = std::views;
+
+void
+test01()
+{
+ auto v = std::deque<int>{};
+ auto i = views::iota(0, 10);
+ auto o = std::front_inserter(v);
+ static_assert(std::output_iterator<decltype(o), int>);
+ ranges::copy(i, o);
+ VERIFY( ranges::equal(v | views::reverse, i) );
+}
+
+int
+main()
+{
+ test01();
+}
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