Tested on x86_64-pc-linux-gnu, does this look OK for trunk only?
libstdc++-v3/ChangeLog:
* include/std/ranges (join_view::_Iterator::_M_satisfy):
Adjust resetting _M_inner as per LWG 3569.
(join_view::_Iterator::_M_inner): Wrap in std::optional
as per LWG 3569.
(join_view::_Iterator::_Iterator): Relax constraints as
per LWG 3569.
(join_view::_Iterator::operator*): Adjust as per LWG 3569.
(join_view::_Iterator::operator->): Likewise.
(join_view::_Iterator::operator++): Likewise.
(join_view::_Iterator::operator--): Likewise.
(join_view::_Iterator::iter_move): Likewise.
(join_view::_Iterator::iter_swap): Likewise.
* testsuite/std/ranges/adaptor/join.cc (test14): New test.
---
libstdc++-v3/include/std/ranges | 28 +++++++++----------
.../testsuite/std/ranges/adaptors/join.cc | 17 +++++++++++
2 files changed, 30 insertions(+), 15 deletions(-)
diff --git a/libstdc++-v3/include/std/ranges b/libstdc++-v3/include/std/ranges
index 20eb4e82ac8..6297ce7cee3 100644
--- a/libstdc++-v3/include/std/ranges
+++ b/libstdc++-v3/include/std/ranges
@@ -2746,7 +2746,7 @@ namespace views::__adaptor
}
if constexpr (_S_ref_is_glvalue)
- _M_inner = _Inner_iter();
+ _M_inner.reset();
}
static constexpr auto
@@ -2769,7 +2769,7 @@ namespace views::__adaptor
using _Inner_iter = join_view::_Inner_iter<_Const>;
_Outer_iter _M_outer = _Outer_iter();
- _Inner_iter _M_inner = _Inner_iter();
+ optional<_Inner_iter> _M_inner;
_Parent* _M_parent = nullptr;
public:
@@ -2780,9 +2780,7 @@ namespace views::__adaptor
= common_type_t<range_difference_t<_Base>,
range_difference_t<range_reference_t<_Base>>>;
- _Iterator() requires (default_initializable<_Outer_iter>
- && default_initializable<_Inner_iter>)
- = default;
+ _Iterator() requires default_initializable<_Outer_iter> = default;
constexpr
_Iterator(_Parent* __parent, _Outer_iter __outer)
@@ -2801,7 +2799,7 @@ namespace views::__adaptor
constexpr decltype(auto)
operator*() const
- { return *_M_inner; }
+ { return **_M_inner; }
// _GLIBCXX_RESOLVE_LIB_DEFECTS
// 3500. join_view::iterator::operator->() is bogus
@@ -2809,7 +2807,7 @@ namespace views::__adaptor
operator->() const
requires __detail::__has_arrow<_Inner_iter>
&& copyable<_Inner_iter>
- { return _M_inner; }
+ { return *_M_inner; }
constexpr _Iterator&
operator++()
@@ -2820,7 +2818,7 @@ namespace views::__adaptor
else
return *_M_parent->_M_inner;
}();
- if (++_M_inner == ranges::end(__inner_range))
+ if (++*_M_inner == ranges::end(__inner_range))
{
++_M_outer;
_M_satisfy();
@@ -2850,9 +2848,9 @@ namespace views::__adaptor
{
if (_M_outer == ranges::end(_M_parent->_M_base))
_M_inner = ranges::end(*--_M_outer);
- while (_M_inner == ranges::begin(*_M_outer))
- _M_inner = ranges::end(*--_M_outer);
- --_M_inner;
+ while (*_M_inner == ranges::begin(*_M_outer))
+ *_M_inner = ranges::end(*--_M_outer);
+ --*_M_inner;
return *this;
}
@@ -2879,14 +2877,14 @@ namespace views::__adaptor
friend constexpr decltype(auto)
iter_move(const _Iterator& __i)
- noexcept(noexcept(ranges::iter_move(__i._M_inner)))
- { return ranges::iter_move(__i._M_inner); }
+ noexcept(noexcept(ranges::iter_move(*__i._M_inner)))
+ { return ranges::iter_move(*__i._M_inner); }
friend constexpr void
iter_swap(const _Iterator& __x, const _Iterator& __y)
- noexcept(noexcept(ranges::iter_swap(__x._M_inner, __y._M_inner)))
+ noexcept(noexcept(ranges::iter_swap(*__x._M_inner, *__y._M_inner)))
requires indirectly_swappable<_Inner_iter>
- { return ranges::iter_swap(__x._M_inner, __y._M_inner); }
+ { return ranges::iter_swap(*__x._M_inner, *__y._M_inner); }
friend _Iterator<!_Const>;
template<bool> friend struct _Sentinel;
diff --git a/libstdc++-v3/testsuite/std/ranges/adaptors/join.cc
b/libstdc++-v3/testsuite/std/ranges/adaptors/join.cc
index 530ab6663b5..afc11d4bd7a 100644
--- a/libstdc++-v3/testsuite/std/ranges/adaptors/join.cc
+++ b/libstdc++-v3/testsuite/std/ranges/adaptors/join.cc
@@ -21,6 +21,7 @@
#include <algorithm>
#include <array>
#include <ranges>
+#include <sstream>
#include <string>
#include <string_view>
#include <vector>
@@ -217,6 +218,21 @@ test13()
std::vector<std::vector<int>> v{{5, 6, 7}};
v | l | std::views::join;
}
+
+void
+test14()
+{
+ // LWG 3569: join_view fails to support ranges of ranges with
+ // non-default_initializable iterators
+ auto ss = std::istringstream{"1 2 3"};
+ auto v = views::single(views::istream<int>(ss));
+ using inner = ranges::range_reference_t<decltype(v)>;
+ static_assert(ranges::input_range<inner>
+ && !ranges::forward_range<inner>
+ && !std::default_initializable<ranges::iterator_t<inner>>);
+ VERIFY( ranges::equal(v | views::join, (int[]){1, 2, 3}) );
+}
+
int
main()
{
@@ -233,4 +249,5 @@ main()
test11();
test12();
test13();
+ test14();
}
--
2.37.3.542.gdd3f6c4cae
