* [PATCH] libstdc++: Implement P2770R0 changes to join_view / join_with_view
@ 2023-04-17 13:39 Patrick Palka
2023-08-16 16:04 ` Patrick Palka
0 siblings, 1 reply; 3+ messages in thread
From: Patrick Palka @ 2023-04-17 13:39 UTC (permalink / raw)
To: gcc-patches; +Cc: libstdc++, Patrick Palka
This C++23 paper fixes a bug in these views when adapting a certain kind
of non-forward range, and we treat it as a DR against C++20.
Tested on x86_64-pc-linux-gnu, does this look OK for GCC 13? This
is an ABI change for join_view so it'd be unsuitable for backporting
later I think :(
libstdc++-v3/ChangeLog:
* include/bits/regex.h (regex_iterator::iterator_concept):
Define for C++20 as per P2770R0.
(regex_token_iterator::iterator_concept): Likewise.
* include/std/ranges (__detail::__as_lvalue): Define.
(join_view::_Iterator): Befriend join_view.
(join_view::_Iterator::_M_satisfy): Use _M_get_outer
instead of _M_outer.
(join_view::_Iterator::_M_get_outer): Define.
(join_view::_Iterator::_Iterator): Split constructor taking
_Parent argument into two as per P2770R0. Remove constraint on
default constructor.
(join_view::_Iterator::_M_outer): Make this data member present
only when the underlying range is forward.
(join_view::_Iterator::operator++): Use _M_get_outer instead of
_M_outer.
(join_view::_Iterator::operator--): Use __as_lvalue helper.
(join_view::_Iterator::operator==): Adjust constraints as per
P2770R0.
(join_view::_Sentinel::__equal): Use _M_get_outer instead of
_M_outer.
(join_view::_M_outer): New data member when the underlying range
is non-forward.
(join_view::begin): Adjust definition as per P2770R0.
(join_view::end): Likewise.
(join_with_view::_M_outer_it): New data member when the
underlying range is non-forward.
(join_with_view::begin): Adjust definition as per P2770R0.
(join_with_view::end): Likewise.
(join_with_view::_Iterator::_M_outer_it): Make this data member
present only when the underlying range is forward.
(join_with_view::_Iterator::_M_get_outer): Define.
(join_with_view::_Iterator::_Iterator): Split constructor
taking _Parent argument into two as per P2770R0. Remove
constraint on default constructor.
(join_with_view::_Iterator::_M_update_inner): Adjust definition
as per P2770R0.
(join_with_view::_Iterator::_M_get_inner): Likewise.
(join_with_view::_Iterator::_M_satisfy): Adjust calls to
_M_get_inner. Use _M_get_outer instead of _M_outer_it.
(join_with_view::_Iterator::operator==): Adjust constraints
as per P2770R0.
(join_with_view::_Sentinel::operator==): Use _M_get_outer
instead of _M_outer_it.
* testsuite/std/ranges/adaptors/p2770r0.cc: New test.
---
libstdc++-v3/include/bits/regex.h | 6 +
libstdc++-v3/include/std/ranges | 190 +++++++++++++-----
.../testsuite/std/ranges/adaptors/p2770r0.cc | 110 ++++++++++
3 files changed, 257 insertions(+), 49 deletions(-)
create mode 100644 libstdc++-v3/testsuite/std/ranges/adaptors/p2770r0.cc
diff --git a/libstdc++-v3/include/bits/regex.h b/libstdc++-v3/include/bits/regex.h
index 26ac6a21c31..2d306868721 100644
--- a/libstdc++-v3/include/bits/regex.h
+++ b/libstdc++-v3/include/bits/regex.h
@@ -2740,6 +2740,9 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
typedef const value_type* pointer;
typedef const value_type& reference;
typedef std::forward_iterator_tag iterator_category;
+#if __cplusplus > 201703L
+ typedef std::input_iterator_tag iterator_concept;
+#endif
/**
* @brief Provides a singular iterator, useful for indicating
@@ -2869,6 +2872,9 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
typedef const value_type* pointer;
typedef const value_type& reference;
typedef std::forward_iterator_tag iterator_category;
+#if __cplusplus > 201703L
+ typedef std::input_iterator_tag iterator_concept;
+#endif
public:
/**
diff --git a/libstdc++-v3/include/std/ranges b/libstdc++-v3/include/std/ranges
index 283d757faa4..ddcf50cc93e 100644
--- a/libstdc++-v3/include/std/ranges
+++ b/libstdc++-v3/include/std/ranges
@@ -2705,6 +2705,14 @@ namespace views::__adaptor
inline constexpr _DropWhile drop_while;
} // namespace views
+ namespace __detail
+ {
+ template<typename _Tp>
+ constexpr _Tp&
+ __as_lvalue(_Tp&& __t)
+ { return static_cast<_Tp&>(__t); }
+ } // namespace __detail
+
template<input_range _Vp>
requires view<_Vp> && input_range<range_reference_t<_Vp>>
class join_view : public view_interface<join_view<_Vp>>
@@ -2767,6 +2775,8 @@ namespace views::__adaptor
using _Parent = __detail::__maybe_const_t<_Const, join_view>;
using _Base = join_view::_Base<_Const>;
+ friend join_view;
+
static constexpr bool _S_ref_is_glvalue
= join_view::_S_ref_is_glvalue<_Const>;
@@ -2780,9 +2790,10 @@ namespace views::__adaptor
return _M_parent->_M_inner._M_emplace_deref(__x);
};
- for (; _M_outer != ranges::end(_M_parent->_M_base); ++_M_outer)
+ _Outer_iter& __outer = _M_get_outer();
+ for (; __outer != ranges::end(_M_parent->_M_base); ++__outer)
{
- auto&& __inner = __update_inner(_M_outer);
+ auto&& __inner = __update_inner(__outer);
_M_inner = ranges::begin(__inner);
if (_M_inner != ranges::end(__inner))
return;
@@ -2811,7 +2822,36 @@ namespace views::__adaptor
using _Outer_iter = join_view::_Outer_iter<_Const>;
using _Inner_iter = join_view::_Inner_iter<_Const>;
- _Outer_iter _M_outer = _Outer_iter();
+ constexpr _Outer_iter&
+ _M_get_outer()
+ {
+ if constexpr (forward_range<_Base>)
+ return _M_outer;
+ else
+ return *_M_parent->_M_outer;
+ }
+
+ constexpr const _Outer_iter&
+ _M_get_outer() const
+ {
+ if constexpr (forward_range<_Base>)
+ return _M_outer;
+ else
+ return *_M_parent->_M_outer;
+ }
+
+ constexpr
+ _Iterator(_Parent* __parent, _Outer_iter __outer) requires forward_range<_Base>
+ : _M_outer(std::move(__outer)), _M_parent(__parent)
+ { _M_satisfy(); }
+
+ constexpr explicit
+ _Iterator(_Parent* __parent) requires (!forward_range<_Base>)
+ : _M_parent(__parent)
+ { _M_satisfy(); }
+
+ [[no_unique_address]]
+ __detail::__maybe_present_t<forward_range<_Base>, _Outer_iter> _M_outer;
optional<_Inner_iter> _M_inner;
_Parent* _M_parent = nullptr;
@@ -2823,13 +2863,7 @@ namespace views::__adaptor
= common_type_t<range_difference_t<_Base>,
range_difference_t<range_reference_t<_Base>>>;
- _Iterator() requires default_initializable<_Outer_iter> = default;
-
- constexpr
- _Iterator(_Parent* __parent, _Outer_iter __outer)
- : _M_outer(std::move(__outer)),
- _M_parent(__parent)
- { _M_satisfy(); }
+ _Iterator() = default;
constexpr
_Iterator(_Iterator<!_Const> __i)
@@ -2857,13 +2891,13 @@ namespace views::__adaptor
{
auto&& __inner_range = [this] () -> auto&& {
if constexpr (_S_ref_is_glvalue)
- return *_M_outer;
+ return *_M_get_outer();
else
return *_M_parent->_M_inner;
}();
if (++*_M_inner == ranges::end(__inner_range))
{
- ++_M_outer;
+ ++_M_get_outer();
_M_satisfy();
}
return *this;
@@ -2890,9 +2924,9 @@ namespace views::__adaptor
&& common_range<range_reference_t<_Base>>
{
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 = ranges::end(__detail::__as_lvalue(*--_M_outer));
+ while (*_M_inner == ranges::begin(__detail::__as_lvalue(*_M_outer)))
+ *_M_inner = ranges::end(__detail::__as_lvalue(*--_M_outer));
--*_M_inner;
return *this;
}
@@ -2911,7 +2945,7 @@ namespace views::__adaptor
friend constexpr bool
operator==(const _Iterator& __x, const _Iterator& __y)
requires _S_ref_is_glvalue
- && equality_comparable<_Outer_iter>
+ && forward_range<_Base>
&& equality_comparable<_Inner_iter>
{
return (__x._M_outer == __y._M_outer
@@ -2943,7 +2977,7 @@ namespace views::__adaptor
template<bool _Const2>
constexpr bool
__equal(const _Iterator<_Const2>& __i) const
- { return __i._M_outer == _M_end; }
+ { return __i._M_get_outer() == _M_end; }
sentinel_t<_Base> _M_end = sentinel_t<_Base>();
@@ -2972,6 +3006,9 @@ namespace views::__adaptor
};
_Vp _M_base = _Vp();
+ [[no_unique_address]]
+ __detail::__maybe_present_t<!forward_range<_Vp>,
+ __detail::__non_propagating_cache<iterator_t<_Vp>>> _M_outer;
[[no_unique_address]]
__detail::__non_propagating_cache<remove_cv_t<_InnerRange>> _M_inner;
@@ -2994,16 +3031,25 @@ namespace views::__adaptor
constexpr auto
begin()
{
- constexpr bool __use_const
- = (__detail::__simple_view<_Vp>
- && is_reference_v<range_reference_t<_Vp>>);
- return _Iterator<__use_const>{this, ranges::begin(_M_base)};
+ if constexpr (forward_range<_Vp>)
+ {
+ constexpr bool __use_const
+ = (__detail::__simple_view<_Vp>
+ && is_reference_v<range_reference_t<_Vp>>);
+ return _Iterator<__use_const>{this, ranges::begin(_M_base)};
+ }
+ else
+ {
+ _M_outer = ranges::begin(_M_base);
+ return _Iterator<false>{this};
+ }
}
constexpr auto
begin() const
- requires input_range<const _Vp>
+ requires forward_range<const _Vp>
&& is_reference_v<range_reference_t<const _Vp>>
+ && input_range<range_reference_t<const _Vp>>
{
return _Iterator<true>{this, ranges::begin(_M_base)};
}
@@ -3022,11 +3068,11 @@ namespace views::__adaptor
constexpr auto
end() const
- requires input_range<const _Vp>
+ requires forward_range<const _Vp>
&& is_reference_v<range_reference_t<const _Vp>>
+ && input_range<range_reference_t<const _Vp>>
{
- if constexpr (forward_range<const _Vp>
- && is_reference_v<range_reference_t<const _Vp>>
+ if constexpr (is_reference_v<range_reference_t<const _Vp>>
&& forward_range<range_reference_t<const _Vp>>
&& common_range<const _Vp>
&& common_range<range_reference_t<const _Vp>>)
@@ -6948,6 +6994,9 @@ namespace views::__adaptor
using _InnerRange = range_reference_t<_Vp>;
_Vp _M_base = _Vp();
+ [[no_unique_address]]
+ __detail::__maybe_present_t<!forward_range<_Vp>,
+ __detail::__non_propagating_cache<iterator_t<_Vp>>> _M_outer_it;
__detail::__non_propagating_cache<remove_cv_t<_InnerRange>> _M_inner;
_Pattern _M_pattern = _Pattern();
@@ -7035,16 +7084,25 @@ namespace views::__adaptor
constexpr auto
begin()
{
- constexpr bool __use_const = is_reference_v<_InnerRange>
- && __detail::__simple_view<_Vp> && __detail::__simple_view<_Pattern>;
- return _Iterator<__use_const>{*this, ranges::begin(_M_base)};
+ if constexpr (forward_range<_Vp>)
+ {
+ constexpr bool __use_const = is_reference_v<_InnerRange>
+ && __detail::__simple_view<_Vp> && __detail::__simple_view<_Pattern>;
+ return _Iterator<__use_const>{*this, ranges::begin(_M_base)};
+ }
+ else
+ {
+ _M_outer_it = ranges::begin(_M_base);
+ return _Iterator<false>{*this};
+ }
}
constexpr auto
begin() const
- requires input_range<const _Vp>
+ requires forward_range<const _Vp>
&& forward_range<const _Pattern>
&& is_reference_v<range_reference_t<const _Vp>>
+ && input_range<range_reference_t<const _Vp>>
{ return _Iterator<true>{*this, ranges::begin(_M_base)}; }
constexpr auto
@@ -7062,13 +7120,13 @@ namespace views::__adaptor
constexpr auto
end() const
- requires input_range<const _Vp>
+ requires forward_range<const _Vp>
&& forward_range<const _Pattern>
&& is_reference_v<range_reference_t<const _Vp>>
+ && input_range<range_reference_t<const _Vp>>
{
using _InnerConstRange = range_reference_t<const _Vp>;
- if constexpr (forward_range<const _Vp>
- && forward_range<_InnerConstRange>
+ if constexpr (forward_range<_InnerConstRange>
&& common_range<const _Vp>
&& common_range<_InnerConstRange>)
return _Iterator<true>{*this, ranges::end(_M_base)};
@@ -7105,35 +7163,69 @@ namespace views::__adaptor
static constexpr bool _S_ref_is_glvalue = join_with_view::_S_ref_is_glvalue<_Const>;
_Parent* _M_parent = nullptr;
- _OuterIter _M_outer_it = _OuterIter();
+ [[no_unique_address]]
+ __detail::__maybe_present_t<forward_range<_Base>, _OuterIter> _M_outer_it;
variant<_PatternIter, _InnerIter> _M_inner_it;
+ constexpr _OuterIter&
+ _M_get_outer()
+ {
+ if constexpr (forward_range<_Base>)
+ return _M_outer_it;
+ else
+ return *_M_parent->_M_outer_it;
+ }
+
+ constexpr const _OuterIter&
+ _M_get_outer() const
+ {
+ if constexpr (forward_range<_Base>)
+ return _M_outer_it;
+ else
+ return *_M_parent->_M_outer_it;
+ }
+
constexpr
- _Iterator(_Parent& __parent, iterator_t<_Base> __outer)
+ _Iterator(_Parent& __parent, _OuterIter __outer)
+ requires forward_range<_Base>
: _M_parent(std::__addressof(__parent)), _M_outer_it(std::move(__outer))
{
- if (_M_outer_it != ranges::end(_M_parent->_M_base))
+ if (_M_get_outer() != ranges::end(_M_parent->_M_base))
+ {
+ auto&& __inner = _M_update_inner();
+ _M_inner_it.template emplace<1>(ranges::begin(__inner));
+ _M_satisfy();
+ }
+ }
+
+ constexpr
+ _Iterator(_Parent& __parent)
+ requires (!forward_range<_Base>)
+ : _M_parent(std::__addressof(__parent))
+ {
+ if (_M_get_outer() != ranges::end(_M_parent->_M_base))
{
- auto&& __inner = _M_update_inner(_M_outer_it);
+ auto&& __inner = _M_update_inner();
_M_inner_it.template emplace<1>(ranges::begin(__inner));
_M_satisfy();
}
}
- constexpr auto&&
- _M_update_inner(const _OuterIter& __x)
+ constexpr auto&
+ _M_update_inner()
{
+ _OuterIter& __outer = _M_get_outer();
if constexpr (_S_ref_is_glvalue)
- return *__x;
+ return __detail::__as_lvalue(*__outer);
else
- return _M_parent->_M_inner._M_emplace_deref(__x);
+ return _M_parent->_M_inner._M_emplace_deref(__outer);
}
- constexpr auto&&
- _M_get_inner(const _OuterIter& __x)
+ constexpr auto&
+ _M_get_inner()
{
if constexpr (_S_ref_is_glvalue)
- return *__x;
+ return __detail::__as_lvalue(*_M_get_outer());
else
return *_M_parent->_M_inner;
}
@@ -7148,16 +7240,16 @@ namespace views::__adaptor
if (std::get<0>(_M_inner_it) != ranges::end(_M_parent->_M_pattern))
break;
- auto&& __inner = _M_update_inner(_M_outer_it);
+ auto&& __inner = _M_update_inner();
_M_inner_it.template emplace<1>(ranges::begin(__inner));
}
else
{
- auto&& __inner = _M_get_inner(_M_outer_it);
+ auto&& __inner = _M_get_inner();
if (std::get<1>(_M_inner_it) != ranges::end(__inner))
break;
- if (++_M_outer_it == ranges::end(_M_parent->_M_base))
+ if (++_M_get_outer() == ranges::end(_M_parent->_M_base))
{
if constexpr (_S_ref_is_glvalue)
_M_inner_it.template emplace<0>();
@@ -7196,7 +7288,7 @@ namespace views::__adaptor
iter_difference_t<_InnerIter>,
iter_difference_t<_PatternIter>>;
- _Iterator() requires default_initializable<_OuterIter> = default;
+ _Iterator() = default;
constexpr
_Iterator(_Iterator<!_Const> __i)
@@ -7306,7 +7398,7 @@ namespace views::__adaptor
friend constexpr bool
operator==(const _Iterator& __x, const _Iterator& __y)
requires _S_ref_is_glvalue
- && equality_comparable<_OuterIter> && equality_comparable<_InnerIter>
+ && forward_range<_Base> && equality_comparable<_InnerIter>
{ return __x._M_outer_it == __y._M_outer_it && __x._M_inner_it ==__y._M_inner_it; }
friend constexpr common_reference_t<iter_rvalue_reference_t<_InnerIter>,
@@ -7373,7 +7465,7 @@ namespace views::__adaptor
iterator_t<__detail::__maybe_const_t<_OtherConst, _Vp>>>
friend constexpr bool
operator==(const _Iterator<_OtherConst>& __x, const _Sentinel& __y)
- { return __x._M_outer_it == __y._M_end; }
+ { return __x._M_get_outer() == __y._M_end; }
};
namespace views
diff --git a/libstdc++-v3/testsuite/std/ranges/adaptors/p2770r0.cc b/libstdc++-v3/testsuite/std/ranges/adaptors/p2770r0.cc
new file mode 100644
index 00000000000..15d71b2faa9
--- /dev/null
+++ b/libstdc++-v3/testsuite/std/ranges/adaptors/p2770r0.cc
@@ -0,0 +1,110 @@
+// { dg-options "-std=gnu++20" }
+// { dg-do run { target c++20 } }
+
+#include <ranges>
+#include <algorithm>
+#include <regex>
+#include <string_view>
+#include <testsuite_hooks.h>
+
+namespace ranges = std::ranges;
+namespace views = std::views;
+
+void
+test01()
+{
+ // Test case from LWG 3698
+ char const text[] = "Hello";
+ std::regex regex{"[a-z]"};
+
+ auto lower
+ = ranges::subrange(std::cregex_iterator(ranges::begin(text),
+ ranges::end(text),
+ regex),
+ std::cregex_iterator{})
+ | views::join
+ | views::transform([](auto const& sm) {
+ return std::string_view(sm.first, sm.second);
+ });
+
+ VERIFY( ranges::equal(lower, (std::string_view[]){"e", "l", "l", "o"}));
+}
+
+void
+test02()
+{
+#if __cpp_lib_ranges_join_with
+ // Analogous test case from LWG 3698 for join_with_view
+ char const text[] = "Hello";
+ std::regex regex{"[a-z]"};
+
+ auto lower
+ = ranges::subrange(std::cregex_iterator(ranges::begin(text),
+ ranges::end(text),
+ regex),
+ std::cregex_iterator{})
+ | views::join_with(views::empty<std::sub_match<const char*>>)
+ | views::transform([](auto const& sm) {
+ return std::string_view(sm.first, sm.second);
+ });
+
+ VERIFY( ranges::equal(lower, (std::string_view[]){"e", "l", "l", "o"}));
+#endif
+}
+
+void
+test03()
+{
+ // Test case from LWG 3700
+ auto r = views::iota(0, 5) | views::split(1);
+ auto s = views::single(r);
+ auto j = s | views::join;
+ auto f = j.front();
+}
+
+void
+test04()
+{
+#if __cpp_lib_ranges_join_with
+ // Analogous test case from LWG 3700 for join_with_view
+ auto r = views::iota(0, 5) | views::split(1);
+ auto s = views::single(r);
+ auto j = s | views::join_with(views::empty<ranges::range_value_t<decltype(r)>>);
+ auto f = j.front();
+#endif
+}
+
+void
+test05()
+{
+ // Test case from LWG 3791
+ std::vector<std::vector<int>> v = {{1}};
+ auto r = v
+ | views::transform([](auto& x) -> auto&& { return std::move(x); })
+ | views::join;
+ auto e = --r.end();
+}
+
+void
+test06()
+{
+#if __cpp_lib_ranges_join_with
+ // Analogous test case from LWG 3791 for join_with_view
+ std::vector<std::vector<int>> v = {{1}};
+ auto r = v
+ | views::transform([](auto& x) -> auto&& { return std::move(x); })
+ | views::join_with(views::empty<int>);
+ auto e = --r.end();
+#endif
+}
+
+int
+main()
+{
+ test01();
+ test02();
+ test03();
+ test04();
+ test05();
+ test06();
+}
--
2.40.0.335.g9857273be0
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] libstdc++: Implement P2770R0 changes to join_view / join_with_view
2023-04-17 13:39 [PATCH] libstdc++: Implement P2770R0 changes to join_view / join_with_view Patrick Palka
@ 2023-08-16 16:04 ` Patrick Palka
2023-08-16 17:28 ` Jonathan Wakely
0 siblings, 1 reply; 3+ messages in thread
From: Patrick Palka @ 2023-08-16 16:04 UTC (permalink / raw)
To: gcc-patches; +Cc: libstdc++
On Mon, Apr 17, 2023 at 9:39 AM Patrick Palka <ppalka@redhat.com> wrote:
>
> This C++23 paper fixes a bug in these views when adapting a certain kind
> of non-forward range, and we treat it as a DR against C++20.
>
> Tested on x86_64-pc-linux-gnu, does this look OK for GCC 13? This
> is an ABI change for join_view so it'd be unsuitable for backporting
> later I think :(
Ping, does this look OK for trunk?
>
> libstdc++-v3/ChangeLog:
>
> * include/bits/regex.h (regex_iterator::iterator_concept):
> Define for C++20 as per P2770R0.
> (regex_token_iterator::iterator_concept): Likewise.
> * include/std/ranges (__detail::__as_lvalue): Define.
> (join_view::_Iterator): Befriend join_view.
> (join_view::_Iterator::_M_satisfy): Use _M_get_outer
> instead of _M_outer.
> (join_view::_Iterator::_M_get_outer): Define.
> (join_view::_Iterator::_Iterator): Split constructor taking
> _Parent argument into two as per P2770R0. Remove constraint on
> default constructor.
> (join_view::_Iterator::_M_outer): Make this data member present
> only when the underlying range is forward.
> (join_view::_Iterator::operator++): Use _M_get_outer instead of
> _M_outer.
> (join_view::_Iterator::operator--): Use __as_lvalue helper.
> (join_view::_Iterator::operator==): Adjust constraints as per
> P2770R0.
> (join_view::_Sentinel::__equal): Use _M_get_outer instead of
> _M_outer.
> (join_view::_M_outer): New data member when the underlying range
> is non-forward.
> (join_view::begin): Adjust definition as per P2770R0.
> (join_view::end): Likewise.
> (join_with_view::_M_outer_it): New data member when the
> underlying range is non-forward.
> (join_with_view::begin): Adjust definition as per P2770R0.
> (join_with_view::end): Likewise.
> (join_with_view::_Iterator::_M_outer_it): Make this data member
> present only when the underlying range is forward.
> (join_with_view::_Iterator::_M_get_outer): Define.
> (join_with_view::_Iterator::_Iterator): Split constructor
> taking _Parent argument into two as per P2770R0. Remove
> constraint on default constructor.
> (join_with_view::_Iterator::_M_update_inner): Adjust definition
> as per P2770R0.
> (join_with_view::_Iterator::_M_get_inner): Likewise.
> (join_with_view::_Iterator::_M_satisfy): Adjust calls to
> _M_get_inner. Use _M_get_outer instead of _M_outer_it.
> (join_with_view::_Iterator::operator==): Adjust constraints
> as per P2770R0.
> (join_with_view::_Sentinel::operator==): Use _M_get_outer
> instead of _M_outer_it.
> * testsuite/std/ranges/adaptors/p2770r0.cc: New test.
> ---
> libstdc++-v3/include/bits/regex.h | 6 +
> libstdc++-v3/include/std/ranges | 190 +++++++++++++-----
> .../testsuite/std/ranges/adaptors/p2770r0.cc | 110 ++++++++++
> 3 files changed, 257 insertions(+), 49 deletions(-)
> create mode 100644 libstdc++-v3/testsuite/std/ranges/adaptors/p2770r0.cc
>
> diff --git a/libstdc++-v3/include/bits/regex.h b/libstdc++-v3/include/bits/regex.h
> index 26ac6a21c31..2d306868721 100644
> --- a/libstdc++-v3/include/bits/regex.h
> +++ b/libstdc++-v3/include/bits/regex.h
> @@ -2740,6 +2740,9 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
> typedef const value_type* pointer;
> typedef const value_type& reference;
> typedef std::forward_iterator_tag iterator_category;
> +#if __cplusplus > 201703L
> + typedef std::input_iterator_tag iterator_concept;
> +#endif
>
> /**
> * @brief Provides a singular iterator, useful for indicating
> @@ -2869,6 +2872,9 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
> typedef const value_type* pointer;
> typedef const value_type& reference;
> typedef std::forward_iterator_tag iterator_category;
> +#if __cplusplus > 201703L
> + typedef std::input_iterator_tag iterator_concept;
> +#endif
>
> public:
> /**
> diff --git a/libstdc++-v3/include/std/ranges b/libstdc++-v3/include/std/ranges
> index 283d757faa4..ddcf50cc93e 100644
> --- a/libstdc++-v3/include/std/ranges
> +++ b/libstdc++-v3/include/std/ranges
> @@ -2705,6 +2705,14 @@ namespace views::__adaptor
> inline constexpr _DropWhile drop_while;
> } // namespace views
>
> + namespace __detail
> + {
> + template<typename _Tp>
> + constexpr _Tp&
> + __as_lvalue(_Tp&& __t)
> + { return static_cast<_Tp&>(__t); }
> + } // namespace __detail
> +
> template<input_range _Vp>
> requires view<_Vp> && input_range<range_reference_t<_Vp>>
> class join_view : public view_interface<join_view<_Vp>>
> @@ -2767,6 +2775,8 @@ namespace views::__adaptor
> using _Parent = __detail::__maybe_const_t<_Const, join_view>;
> using _Base = join_view::_Base<_Const>;
>
> + friend join_view;
> +
> static constexpr bool _S_ref_is_glvalue
> = join_view::_S_ref_is_glvalue<_Const>;
>
> @@ -2780,9 +2790,10 @@ namespace views::__adaptor
> return _M_parent->_M_inner._M_emplace_deref(__x);
> };
>
> - for (; _M_outer != ranges::end(_M_parent->_M_base); ++_M_outer)
> + _Outer_iter& __outer = _M_get_outer();
> + for (; __outer != ranges::end(_M_parent->_M_base); ++__outer)
> {
> - auto&& __inner = __update_inner(_M_outer);
> + auto&& __inner = __update_inner(__outer);
> _M_inner = ranges::begin(__inner);
> if (_M_inner != ranges::end(__inner))
> return;
> @@ -2811,7 +2822,36 @@ namespace views::__adaptor
> using _Outer_iter = join_view::_Outer_iter<_Const>;
> using _Inner_iter = join_view::_Inner_iter<_Const>;
>
> - _Outer_iter _M_outer = _Outer_iter();
> + constexpr _Outer_iter&
> + _M_get_outer()
> + {
> + if constexpr (forward_range<_Base>)
> + return _M_outer;
> + else
> + return *_M_parent->_M_outer;
> + }
> +
> + constexpr const _Outer_iter&
> + _M_get_outer() const
> + {
> + if constexpr (forward_range<_Base>)
> + return _M_outer;
> + else
> + return *_M_parent->_M_outer;
> + }
> +
> + constexpr
> + _Iterator(_Parent* __parent, _Outer_iter __outer) requires forward_range<_Base>
> + : _M_outer(std::move(__outer)), _M_parent(__parent)
> + { _M_satisfy(); }
> +
> + constexpr explicit
> + _Iterator(_Parent* __parent) requires (!forward_range<_Base>)
> + : _M_parent(__parent)
> + { _M_satisfy(); }
> +
> + [[no_unique_address]]
> + __detail::__maybe_present_t<forward_range<_Base>, _Outer_iter> _M_outer;
> optional<_Inner_iter> _M_inner;
> _Parent* _M_parent = nullptr;
>
> @@ -2823,13 +2863,7 @@ namespace views::__adaptor
> = common_type_t<range_difference_t<_Base>,
> range_difference_t<range_reference_t<_Base>>>;
>
> - _Iterator() requires default_initializable<_Outer_iter> = default;
> -
> - constexpr
> - _Iterator(_Parent* __parent, _Outer_iter __outer)
> - : _M_outer(std::move(__outer)),
> - _M_parent(__parent)
> - { _M_satisfy(); }
> + _Iterator() = default;
>
> constexpr
> _Iterator(_Iterator<!_Const> __i)
> @@ -2857,13 +2891,13 @@ namespace views::__adaptor
> {
> auto&& __inner_range = [this] () -> auto&& {
> if constexpr (_S_ref_is_glvalue)
> - return *_M_outer;
> + return *_M_get_outer();
> else
> return *_M_parent->_M_inner;
> }();
> if (++*_M_inner == ranges::end(__inner_range))
> {
> - ++_M_outer;
> + ++_M_get_outer();
> _M_satisfy();
> }
> return *this;
> @@ -2890,9 +2924,9 @@ namespace views::__adaptor
> && common_range<range_reference_t<_Base>>
> {
> 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 = ranges::end(__detail::__as_lvalue(*--_M_outer));
> + while (*_M_inner == ranges::begin(__detail::__as_lvalue(*_M_outer)))
> + *_M_inner = ranges::end(__detail::__as_lvalue(*--_M_outer));
> --*_M_inner;
> return *this;
> }
> @@ -2911,7 +2945,7 @@ namespace views::__adaptor
> friend constexpr bool
> operator==(const _Iterator& __x, const _Iterator& __y)
> requires _S_ref_is_glvalue
> - && equality_comparable<_Outer_iter>
> + && forward_range<_Base>
> && equality_comparable<_Inner_iter>
> {
> return (__x._M_outer == __y._M_outer
> @@ -2943,7 +2977,7 @@ namespace views::__adaptor
> template<bool _Const2>
> constexpr bool
> __equal(const _Iterator<_Const2>& __i) const
> - { return __i._M_outer == _M_end; }
> + { return __i._M_get_outer() == _M_end; }
>
> sentinel_t<_Base> _M_end = sentinel_t<_Base>();
>
> @@ -2972,6 +3006,9 @@ namespace views::__adaptor
> };
>
> _Vp _M_base = _Vp();
> + [[no_unique_address]]
> + __detail::__maybe_present_t<!forward_range<_Vp>,
> + __detail::__non_propagating_cache<iterator_t<_Vp>>> _M_outer;
> [[no_unique_address]]
> __detail::__non_propagating_cache<remove_cv_t<_InnerRange>> _M_inner;
>
> @@ -2994,16 +3031,25 @@ namespace views::__adaptor
> constexpr auto
> begin()
> {
> - constexpr bool __use_const
> - = (__detail::__simple_view<_Vp>
> - && is_reference_v<range_reference_t<_Vp>>);
> - return _Iterator<__use_const>{this, ranges::begin(_M_base)};
> + if constexpr (forward_range<_Vp>)
> + {
> + constexpr bool __use_const
> + = (__detail::__simple_view<_Vp>
> + && is_reference_v<range_reference_t<_Vp>>);
> + return _Iterator<__use_const>{this, ranges::begin(_M_base)};
> + }
> + else
> + {
> + _M_outer = ranges::begin(_M_base);
> + return _Iterator<false>{this};
> + }
> }
>
> constexpr auto
> begin() const
> - requires input_range<const _Vp>
> + requires forward_range<const _Vp>
> && is_reference_v<range_reference_t<const _Vp>>
> + && input_range<range_reference_t<const _Vp>>
> {
> return _Iterator<true>{this, ranges::begin(_M_base)};
> }
> @@ -3022,11 +3068,11 @@ namespace views::__adaptor
>
> constexpr auto
> end() const
> - requires input_range<const _Vp>
> + requires forward_range<const _Vp>
> && is_reference_v<range_reference_t<const _Vp>>
> + && input_range<range_reference_t<const _Vp>>
> {
> - if constexpr (forward_range<const _Vp>
> - && is_reference_v<range_reference_t<const _Vp>>
> + if constexpr (is_reference_v<range_reference_t<const _Vp>>
> && forward_range<range_reference_t<const _Vp>>
> && common_range<const _Vp>
> && common_range<range_reference_t<const _Vp>>)
> @@ -6948,6 +6994,9 @@ namespace views::__adaptor
> using _InnerRange = range_reference_t<_Vp>;
>
> _Vp _M_base = _Vp();
> + [[no_unique_address]]
> + __detail::__maybe_present_t<!forward_range<_Vp>,
> + __detail::__non_propagating_cache<iterator_t<_Vp>>> _M_outer_it;
> __detail::__non_propagating_cache<remove_cv_t<_InnerRange>> _M_inner;
> _Pattern _M_pattern = _Pattern();
>
> @@ -7035,16 +7084,25 @@ namespace views::__adaptor
> constexpr auto
> begin()
> {
> - constexpr bool __use_const = is_reference_v<_InnerRange>
> - && __detail::__simple_view<_Vp> && __detail::__simple_view<_Pattern>;
> - return _Iterator<__use_const>{*this, ranges::begin(_M_base)};
> + if constexpr (forward_range<_Vp>)
> + {
> + constexpr bool __use_const = is_reference_v<_InnerRange>
> + && __detail::__simple_view<_Vp> && __detail::__simple_view<_Pattern>;
> + return _Iterator<__use_const>{*this, ranges::begin(_M_base)};
> + }
> + else
> + {
> + _M_outer_it = ranges::begin(_M_base);
> + return _Iterator<false>{*this};
> + }
> }
>
> constexpr auto
> begin() const
> - requires input_range<const _Vp>
> + requires forward_range<const _Vp>
> && forward_range<const _Pattern>
> && is_reference_v<range_reference_t<const _Vp>>
> + && input_range<range_reference_t<const _Vp>>
> { return _Iterator<true>{*this, ranges::begin(_M_base)}; }
>
> constexpr auto
> @@ -7062,13 +7120,13 @@ namespace views::__adaptor
>
> constexpr auto
> end() const
> - requires input_range<const _Vp>
> + requires forward_range<const _Vp>
> && forward_range<const _Pattern>
> && is_reference_v<range_reference_t<const _Vp>>
> + && input_range<range_reference_t<const _Vp>>
> {
> using _InnerConstRange = range_reference_t<const _Vp>;
> - if constexpr (forward_range<const _Vp>
> - && forward_range<_InnerConstRange>
> + if constexpr (forward_range<_InnerConstRange>
> && common_range<const _Vp>
> && common_range<_InnerConstRange>)
> return _Iterator<true>{*this, ranges::end(_M_base)};
> @@ -7105,35 +7163,69 @@ namespace views::__adaptor
> static constexpr bool _S_ref_is_glvalue = join_with_view::_S_ref_is_glvalue<_Const>;
>
> _Parent* _M_parent = nullptr;
> - _OuterIter _M_outer_it = _OuterIter();
> + [[no_unique_address]]
> + __detail::__maybe_present_t<forward_range<_Base>, _OuterIter> _M_outer_it;
> variant<_PatternIter, _InnerIter> _M_inner_it;
>
> + constexpr _OuterIter&
> + _M_get_outer()
> + {
> + if constexpr (forward_range<_Base>)
> + return _M_outer_it;
> + else
> + return *_M_parent->_M_outer_it;
> + }
> +
> + constexpr const _OuterIter&
> + _M_get_outer() const
> + {
> + if constexpr (forward_range<_Base>)
> + return _M_outer_it;
> + else
> + return *_M_parent->_M_outer_it;
> + }
> +
> constexpr
> - _Iterator(_Parent& __parent, iterator_t<_Base> __outer)
> + _Iterator(_Parent& __parent, _OuterIter __outer)
> + requires forward_range<_Base>
> : _M_parent(std::__addressof(__parent)), _M_outer_it(std::move(__outer))
> {
> - if (_M_outer_it != ranges::end(_M_parent->_M_base))
> + if (_M_get_outer() != ranges::end(_M_parent->_M_base))
> + {
> + auto&& __inner = _M_update_inner();
> + _M_inner_it.template emplace<1>(ranges::begin(__inner));
> + _M_satisfy();
> + }
> + }
> +
> + constexpr
> + _Iterator(_Parent& __parent)
> + requires (!forward_range<_Base>)
> + : _M_parent(std::__addressof(__parent))
> + {
> + if (_M_get_outer() != ranges::end(_M_parent->_M_base))
> {
> - auto&& __inner = _M_update_inner(_M_outer_it);
> + auto&& __inner = _M_update_inner();
> _M_inner_it.template emplace<1>(ranges::begin(__inner));
> _M_satisfy();
> }
> }
>
> - constexpr auto&&
> - _M_update_inner(const _OuterIter& __x)
> + constexpr auto&
> + _M_update_inner()
> {
> + _OuterIter& __outer = _M_get_outer();
> if constexpr (_S_ref_is_glvalue)
> - return *__x;
> + return __detail::__as_lvalue(*__outer);
> else
> - return _M_parent->_M_inner._M_emplace_deref(__x);
> + return _M_parent->_M_inner._M_emplace_deref(__outer);
> }
>
> - constexpr auto&&
> - _M_get_inner(const _OuterIter& __x)
> + constexpr auto&
> + _M_get_inner()
> {
> if constexpr (_S_ref_is_glvalue)
> - return *__x;
> + return __detail::__as_lvalue(*_M_get_outer());
> else
> return *_M_parent->_M_inner;
> }
> @@ -7148,16 +7240,16 @@ namespace views::__adaptor
> if (std::get<0>(_M_inner_it) != ranges::end(_M_parent->_M_pattern))
> break;
>
> - auto&& __inner = _M_update_inner(_M_outer_it);
> + auto&& __inner = _M_update_inner();
> _M_inner_it.template emplace<1>(ranges::begin(__inner));
> }
> else
> {
> - auto&& __inner = _M_get_inner(_M_outer_it);
> + auto&& __inner = _M_get_inner();
> if (std::get<1>(_M_inner_it) != ranges::end(__inner))
> break;
>
> - if (++_M_outer_it == ranges::end(_M_parent->_M_base))
> + if (++_M_get_outer() == ranges::end(_M_parent->_M_base))
> {
> if constexpr (_S_ref_is_glvalue)
> _M_inner_it.template emplace<0>();
> @@ -7196,7 +7288,7 @@ namespace views::__adaptor
> iter_difference_t<_InnerIter>,
> iter_difference_t<_PatternIter>>;
>
> - _Iterator() requires default_initializable<_OuterIter> = default;
> + _Iterator() = default;
>
> constexpr
> _Iterator(_Iterator<!_Const> __i)
> @@ -7306,7 +7398,7 @@ namespace views::__adaptor
> friend constexpr bool
> operator==(const _Iterator& __x, const _Iterator& __y)
> requires _S_ref_is_glvalue
> - && equality_comparable<_OuterIter> && equality_comparable<_InnerIter>
> + && forward_range<_Base> && equality_comparable<_InnerIter>
> { return __x._M_outer_it == __y._M_outer_it && __x._M_inner_it ==__y._M_inner_it; }
>
> friend constexpr common_reference_t<iter_rvalue_reference_t<_InnerIter>,
> @@ -7373,7 +7465,7 @@ namespace views::__adaptor
> iterator_t<__detail::__maybe_const_t<_OtherConst, _Vp>>>
> friend constexpr bool
> operator==(const _Iterator<_OtherConst>& __x, const _Sentinel& __y)
> - { return __x._M_outer_it == __y._M_end; }
> + { return __x._M_get_outer() == __y._M_end; }
> };
>
> namespace views
> diff --git a/libstdc++-v3/testsuite/std/ranges/adaptors/p2770r0.cc b/libstdc++-v3/testsuite/std/ranges/adaptors/p2770r0.cc
> new file mode 100644
> index 00000000000..15d71b2faa9
> --- /dev/null
> +++ b/libstdc++-v3/testsuite/std/ranges/adaptors/p2770r0.cc
> @@ -0,0 +1,110 @@
> +// { dg-options "-std=gnu++20" }
> +// { dg-do run { target c++20 } }
> +
> +#include <ranges>
> +#include <algorithm>
> +#include <regex>
> +#include <string_view>
> +#include <testsuite_hooks.h>
> +
> +namespace ranges = std::ranges;
> +namespace views = std::views;
> +
> +void
> +test01()
> +{
> + // Test case from LWG 3698
> + char const text[] = "Hello";
> + std::regex regex{"[a-z]"};
> +
> + auto lower
> + = ranges::subrange(std::cregex_iterator(ranges::begin(text),
> + ranges::end(text),
> + regex),
> + std::cregex_iterator{})
> + | views::join
> + | views::transform([](auto const& sm) {
> + return std::string_view(sm.first, sm.second);
> + });
> +
> + VERIFY( ranges::equal(lower, (std::string_view[]){"e", "l", "l", "o"}));
> +}
> +
> +void
> +test02()
> +{
> +#if __cpp_lib_ranges_join_with
> + // Analogous test case from LWG 3698 for join_with_view
> + char const text[] = "Hello";
> + std::regex regex{"[a-z]"};
> +
> + auto lower
> + = ranges::subrange(std::cregex_iterator(ranges::begin(text),
> + ranges::end(text),
> + regex),
> + std::cregex_iterator{})
> + | views::join_with(views::empty<std::sub_match<const char*>>)
> + | views::transform([](auto const& sm) {
> + return std::string_view(sm.first, sm.second);
> + });
> +
> + VERIFY( ranges::equal(lower, (std::string_view[]){"e", "l", "l", "o"}));
> +#endif
> +}
> +
> +void
> +test03()
> +{
> + // Test case from LWG 3700
> + auto r = views::iota(0, 5) | views::split(1);
> + auto s = views::single(r);
> + auto j = s | views::join;
> + auto f = j.front();
> +}
> +
> +void
> +test04()
> +{
> +#if __cpp_lib_ranges_join_with
> + // Analogous test case from LWG 3700 for join_with_view
> + auto r = views::iota(0, 5) | views::split(1);
> + auto s = views::single(r);
> + auto j = s | views::join_with(views::empty<ranges::range_value_t<decltype(r)>>);
> + auto f = j.front();
> +#endif
> +}
> +
> +void
> +test05()
> +{
> + // Test case from LWG 3791
> + std::vector<std::vector<int>> v = {{1}};
> + auto r = v
> + | views::transform([](auto& x) -> auto&& { return std::move(x); })
> + | views::join;
> + auto e = --r.end();
> +}
> +
> +void
> +test06()
> +{
> +#if __cpp_lib_ranges_join_with
> + // Analogous test case from LWG 3791 for join_with_view
> + std::vector<std::vector<int>> v = {{1}};
> + auto r = v
> + | views::transform([](auto& x) -> auto&& { return std::move(x); })
> + | views::join_with(views::empty<int>);
> + auto e = --r.end();
> +#endif
> +}
> +
> +int
> +main()
> +{
> + test01();
> + test02();
> + test03();
> + test04();
> + test05();
> + test06();
> +}
> --
> 2.40.0.335.g9857273be0
>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] libstdc++: Implement P2770R0 changes to join_view / join_with_view
2023-08-16 16:04 ` Patrick Palka
@ 2023-08-16 17:28 ` Jonathan Wakely
0 siblings, 0 replies; 3+ messages in thread
From: Jonathan Wakely @ 2023-08-16 17:28 UTC (permalink / raw)
To: Patrick Palka; +Cc: gcc-patches, libstdc++
On Wed, 16 Aug 2023 at 17:05, Patrick Palka via Libstdc++
<libstdc++@gcc.gnu.org> wrote:
>
> On Mon, Apr 17, 2023 at 9:39 AM Patrick Palka <ppalka@redhat.com> wrote:
> >
> > This C++23 paper fixes a bug in these views when adapting a certain kind
> > of non-forward range, and we treat it as a DR against C++20.
> >
> > Tested on x86_64-pc-linux-gnu, does this look OK for GCC 13? This
> > is an ABI change for join_view so it'd be unsuitable for backporting
> > later I think :(
>
> Ping, does this look OK for trunk?
Looks like I completely missed this one, sorry.
OK for trunk.
>
> >
> > libstdc++-v3/ChangeLog:
> >
> > * include/bits/regex.h (regex_iterator::iterator_concept):
> > Define for C++20 as per P2770R0.
> > (regex_token_iterator::iterator_concept): Likewise.
> > * include/std/ranges (__detail::__as_lvalue): Define.
> > (join_view::_Iterator): Befriend join_view.
> > (join_view::_Iterator::_M_satisfy): Use _M_get_outer
> > instead of _M_outer.
> > (join_view::_Iterator::_M_get_outer): Define.
> > (join_view::_Iterator::_Iterator): Split constructor taking
> > _Parent argument into two as per P2770R0. Remove constraint on
> > default constructor.
> > (join_view::_Iterator::_M_outer): Make this data member present
> > only when the underlying range is forward.
> > (join_view::_Iterator::operator++): Use _M_get_outer instead of
> > _M_outer.
> > (join_view::_Iterator::operator--): Use __as_lvalue helper.
> > (join_view::_Iterator::operator==): Adjust constraints as per
> > P2770R0.
> > (join_view::_Sentinel::__equal): Use _M_get_outer instead of
> > _M_outer.
> > (join_view::_M_outer): New data member when the underlying range
> > is non-forward.
> > (join_view::begin): Adjust definition as per P2770R0.
> > (join_view::end): Likewise.
> > (join_with_view::_M_outer_it): New data member when the
> > underlying range is non-forward.
> > (join_with_view::begin): Adjust definition as per P2770R0.
> > (join_with_view::end): Likewise.
> > (join_with_view::_Iterator::_M_outer_it): Make this data member
> > present only when the underlying range is forward.
> > (join_with_view::_Iterator::_M_get_outer): Define.
> > (join_with_view::_Iterator::_Iterator): Split constructor
> > taking _Parent argument into two as per P2770R0. Remove
> > constraint on default constructor.
> > (join_with_view::_Iterator::_M_update_inner): Adjust definition
> > as per P2770R0.
> > (join_with_view::_Iterator::_M_get_inner): Likewise.
> > (join_with_view::_Iterator::_M_satisfy): Adjust calls to
> > _M_get_inner. Use _M_get_outer instead of _M_outer_it.
> > (join_with_view::_Iterator::operator==): Adjust constraints
> > as per P2770R0.
> > (join_with_view::_Sentinel::operator==): Use _M_get_outer
> > instead of _M_outer_it.
> > * testsuite/std/ranges/adaptors/p2770r0.cc: New test.
> > ---
> > libstdc++-v3/include/bits/regex.h | 6 +
> > libstdc++-v3/include/std/ranges | 190 +++++++++++++-----
> > .../testsuite/std/ranges/adaptors/p2770r0.cc | 110 ++++++++++
> > 3 files changed, 257 insertions(+), 49 deletions(-)
> > create mode 100644 libstdc++-v3/testsuite/std/ranges/adaptors/p2770r0.cc
> >
> > diff --git a/libstdc++-v3/include/bits/regex.h b/libstdc++-v3/include/bits/regex.h
> > index 26ac6a21c31..2d306868721 100644
> > --- a/libstdc++-v3/include/bits/regex.h
> > +++ b/libstdc++-v3/include/bits/regex.h
> > @@ -2740,6 +2740,9 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
> > typedef const value_type* pointer;
> > typedef const value_type& reference;
> > typedef std::forward_iterator_tag iterator_category;
> > +#if __cplusplus > 201703L
> > + typedef std::input_iterator_tag iterator_concept;
> > +#endif
> >
> > /**
> > * @brief Provides a singular iterator, useful for indicating
> > @@ -2869,6 +2872,9 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
> > typedef const value_type* pointer;
> > typedef const value_type& reference;
> > typedef std::forward_iterator_tag iterator_category;
> > +#if __cplusplus > 201703L
> > + typedef std::input_iterator_tag iterator_concept;
> > +#endif
> >
> > public:
> > /**
> > diff --git a/libstdc++-v3/include/std/ranges b/libstdc++-v3/include/std/ranges
> > index 283d757faa4..ddcf50cc93e 100644
> > --- a/libstdc++-v3/include/std/ranges
> > +++ b/libstdc++-v3/include/std/ranges
> > @@ -2705,6 +2705,14 @@ namespace views::__adaptor
> > inline constexpr _DropWhile drop_while;
> > } // namespace views
> >
> > + namespace __detail
> > + {
> > + template<typename _Tp>
> > + constexpr _Tp&
> > + __as_lvalue(_Tp&& __t)
> > + { return static_cast<_Tp&>(__t); }
> > + } // namespace __detail
> > +
> > template<input_range _Vp>
> > requires view<_Vp> && input_range<range_reference_t<_Vp>>
> > class join_view : public view_interface<join_view<_Vp>>
> > @@ -2767,6 +2775,8 @@ namespace views::__adaptor
> > using _Parent = __detail::__maybe_const_t<_Const, join_view>;
> > using _Base = join_view::_Base<_Const>;
> >
> > + friend join_view;
> > +
> > static constexpr bool _S_ref_is_glvalue
> > = join_view::_S_ref_is_glvalue<_Const>;
> >
> > @@ -2780,9 +2790,10 @@ namespace views::__adaptor
> > return _M_parent->_M_inner._M_emplace_deref(__x);
> > };
> >
> > - for (; _M_outer != ranges::end(_M_parent->_M_base); ++_M_outer)
> > + _Outer_iter& __outer = _M_get_outer();
> > + for (; __outer != ranges::end(_M_parent->_M_base); ++__outer)
> > {
> > - auto&& __inner = __update_inner(_M_outer);
> > + auto&& __inner = __update_inner(__outer);
> > _M_inner = ranges::begin(__inner);
> > if (_M_inner != ranges::end(__inner))
> > return;
> > @@ -2811,7 +2822,36 @@ namespace views::__adaptor
> > using _Outer_iter = join_view::_Outer_iter<_Const>;
> > using _Inner_iter = join_view::_Inner_iter<_Const>;
> >
> > - _Outer_iter _M_outer = _Outer_iter();
> > + constexpr _Outer_iter&
> > + _M_get_outer()
> > + {
> > + if constexpr (forward_range<_Base>)
> > + return _M_outer;
> > + else
> > + return *_M_parent->_M_outer;
> > + }
> > +
> > + constexpr const _Outer_iter&
> > + _M_get_outer() const
> > + {
> > + if constexpr (forward_range<_Base>)
> > + return _M_outer;
> > + else
> > + return *_M_parent->_M_outer;
> > + }
> > +
> > + constexpr
> > + _Iterator(_Parent* __parent, _Outer_iter __outer) requires forward_range<_Base>
> > + : _M_outer(std::move(__outer)), _M_parent(__parent)
> > + { _M_satisfy(); }
> > +
> > + constexpr explicit
> > + _Iterator(_Parent* __parent) requires (!forward_range<_Base>)
> > + : _M_parent(__parent)
> > + { _M_satisfy(); }
> > +
> > + [[no_unique_address]]
> > + __detail::__maybe_present_t<forward_range<_Base>, _Outer_iter> _M_outer;
> > optional<_Inner_iter> _M_inner;
> > _Parent* _M_parent = nullptr;
> >
> > @@ -2823,13 +2863,7 @@ namespace views::__adaptor
> > = common_type_t<range_difference_t<_Base>,
> > range_difference_t<range_reference_t<_Base>>>;
> >
> > - _Iterator() requires default_initializable<_Outer_iter> = default;
> > -
> > - constexpr
> > - _Iterator(_Parent* __parent, _Outer_iter __outer)
> > - : _M_outer(std::move(__outer)),
> > - _M_parent(__parent)
> > - { _M_satisfy(); }
> > + _Iterator() = default;
> >
> > constexpr
> > _Iterator(_Iterator<!_Const> __i)
> > @@ -2857,13 +2891,13 @@ namespace views::__adaptor
> > {
> > auto&& __inner_range = [this] () -> auto&& {
> > if constexpr (_S_ref_is_glvalue)
> > - return *_M_outer;
> > + return *_M_get_outer();
> > else
> > return *_M_parent->_M_inner;
> > }();
> > if (++*_M_inner == ranges::end(__inner_range))
> > {
> > - ++_M_outer;
> > + ++_M_get_outer();
> > _M_satisfy();
> > }
> > return *this;
> > @@ -2890,9 +2924,9 @@ namespace views::__adaptor
> > && common_range<range_reference_t<_Base>>
> > {
> > 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 = ranges::end(__detail::__as_lvalue(*--_M_outer));
> > + while (*_M_inner == ranges::begin(__detail::__as_lvalue(*_M_outer)))
> > + *_M_inner = ranges::end(__detail::__as_lvalue(*--_M_outer));
> > --*_M_inner;
> > return *this;
> > }
> > @@ -2911,7 +2945,7 @@ namespace views::__adaptor
> > friend constexpr bool
> > operator==(const _Iterator& __x, const _Iterator& __y)
> > requires _S_ref_is_glvalue
> > - && equality_comparable<_Outer_iter>
> > + && forward_range<_Base>
> > && equality_comparable<_Inner_iter>
> > {
> > return (__x._M_outer == __y._M_outer
> > @@ -2943,7 +2977,7 @@ namespace views::__adaptor
> > template<bool _Const2>
> > constexpr bool
> > __equal(const _Iterator<_Const2>& __i) const
> > - { return __i._M_outer == _M_end; }
> > + { return __i._M_get_outer() == _M_end; }
> >
> > sentinel_t<_Base> _M_end = sentinel_t<_Base>();
> >
> > @@ -2972,6 +3006,9 @@ namespace views::__adaptor
> > };
> >
> > _Vp _M_base = _Vp();
> > + [[no_unique_address]]
> > + __detail::__maybe_present_t<!forward_range<_Vp>,
> > + __detail::__non_propagating_cache<iterator_t<_Vp>>> _M_outer;
> > [[no_unique_address]]
> > __detail::__non_propagating_cache<remove_cv_t<_InnerRange>> _M_inner;
> >
> > @@ -2994,16 +3031,25 @@ namespace views::__adaptor
> > constexpr auto
> > begin()
> > {
> > - constexpr bool __use_const
> > - = (__detail::__simple_view<_Vp>
> > - && is_reference_v<range_reference_t<_Vp>>);
> > - return _Iterator<__use_const>{this, ranges::begin(_M_base)};
> > + if constexpr (forward_range<_Vp>)
> > + {
> > + constexpr bool __use_const
> > + = (__detail::__simple_view<_Vp>
> > + && is_reference_v<range_reference_t<_Vp>>);
> > + return _Iterator<__use_const>{this, ranges::begin(_M_base)};
> > + }
> > + else
> > + {
> > + _M_outer = ranges::begin(_M_base);
> > + return _Iterator<false>{this};
> > + }
> > }
> >
> > constexpr auto
> > begin() const
> > - requires input_range<const _Vp>
> > + requires forward_range<const _Vp>
> > && is_reference_v<range_reference_t<const _Vp>>
> > + && input_range<range_reference_t<const _Vp>>
> > {
> > return _Iterator<true>{this, ranges::begin(_M_base)};
> > }
> > @@ -3022,11 +3068,11 @@ namespace views::__adaptor
> >
> > constexpr auto
> > end() const
> > - requires input_range<const _Vp>
> > + requires forward_range<const _Vp>
> > && is_reference_v<range_reference_t<const _Vp>>
> > + && input_range<range_reference_t<const _Vp>>
> > {
> > - if constexpr (forward_range<const _Vp>
> > - && is_reference_v<range_reference_t<const _Vp>>
> > + if constexpr (is_reference_v<range_reference_t<const _Vp>>
> > && forward_range<range_reference_t<const _Vp>>
> > && common_range<const _Vp>
> > && common_range<range_reference_t<const _Vp>>)
> > @@ -6948,6 +6994,9 @@ namespace views::__adaptor
> > using _InnerRange = range_reference_t<_Vp>;
> >
> > _Vp _M_base = _Vp();
> > + [[no_unique_address]]
> > + __detail::__maybe_present_t<!forward_range<_Vp>,
> > + __detail::__non_propagating_cache<iterator_t<_Vp>>> _M_outer_it;
> > __detail::__non_propagating_cache<remove_cv_t<_InnerRange>> _M_inner;
> > _Pattern _M_pattern = _Pattern();
> >
> > @@ -7035,16 +7084,25 @@ namespace views::__adaptor
> > constexpr auto
> > begin()
> > {
> > - constexpr bool __use_const = is_reference_v<_InnerRange>
> > - && __detail::__simple_view<_Vp> && __detail::__simple_view<_Pattern>;
> > - return _Iterator<__use_const>{*this, ranges::begin(_M_base)};
> > + if constexpr (forward_range<_Vp>)
> > + {
> > + constexpr bool __use_const = is_reference_v<_InnerRange>
> > + && __detail::__simple_view<_Vp> && __detail::__simple_view<_Pattern>;
> > + return _Iterator<__use_const>{*this, ranges::begin(_M_base)};
> > + }
> > + else
> > + {
> > + _M_outer_it = ranges::begin(_M_base);
> > + return _Iterator<false>{*this};
> > + }
> > }
> >
> > constexpr auto
> > begin() const
> > - requires input_range<const _Vp>
> > + requires forward_range<const _Vp>
> > && forward_range<const _Pattern>
> > && is_reference_v<range_reference_t<const _Vp>>
> > + && input_range<range_reference_t<const _Vp>>
> > { return _Iterator<true>{*this, ranges::begin(_M_base)}; }
> >
> > constexpr auto
> > @@ -7062,13 +7120,13 @@ namespace views::__adaptor
> >
> > constexpr auto
> > end() const
> > - requires input_range<const _Vp>
> > + requires forward_range<const _Vp>
> > && forward_range<const _Pattern>
> > && is_reference_v<range_reference_t<const _Vp>>
> > + && input_range<range_reference_t<const _Vp>>
> > {
> > using _InnerConstRange = range_reference_t<const _Vp>;
> > - if constexpr (forward_range<const _Vp>
> > - && forward_range<_InnerConstRange>
> > + if constexpr (forward_range<_InnerConstRange>
> > && common_range<const _Vp>
> > && common_range<_InnerConstRange>)
> > return _Iterator<true>{*this, ranges::end(_M_base)};
> > @@ -7105,35 +7163,69 @@ namespace views::__adaptor
> > static constexpr bool _S_ref_is_glvalue = join_with_view::_S_ref_is_glvalue<_Const>;
> >
> > _Parent* _M_parent = nullptr;
> > - _OuterIter _M_outer_it = _OuterIter();
> > + [[no_unique_address]]
> > + __detail::__maybe_present_t<forward_range<_Base>, _OuterIter> _M_outer_it;
> > variant<_PatternIter, _InnerIter> _M_inner_it;
> >
> > + constexpr _OuterIter&
> > + _M_get_outer()
> > + {
> > + if constexpr (forward_range<_Base>)
> > + return _M_outer_it;
> > + else
> > + return *_M_parent->_M_outer_it;
> > + }
> > +
> > + constexpr const _OuterIter&
> > + _M_get_outer() const
> > + {
> > + if constexpr (forward_range<_Base>)
> > + return _M_outer_it;
> > + else
> > + return *_M_parent->_M_outer_it;
> > + }
> > +
> > constexpr
> > - _Iterator(_Parent& __parent, iterator_t<_Base> __outer)
> > + _Iterator(_Parent& __parent, _OuterIter __outer)
> > + requires forward_range<_Base>
> > : _M_parent(std::__addressof(__parent)), _M_outer_it(std::move(__outer))
> > {
> > - if (_M_outer_it != ranges::end(_M_parent->_M_base))
> > + if (_M_get_outer() != ranges::end(_M_parent->_M_base))
> > + {
> > + auto&& __inner = _M_update_inner();
> > + _M_inner_it.template emplace<1>(ranges::begin(__inner));
> > + _M_satisfy();
> > + }
> > + }
> > +
> > + constexpr
> > + _Iterator(_Parent& __parent)
> > + requires (!forward_range<_Base>)
> > + : _M_parent(std::__addressof(__parent))
> > + {
> > + if (_M_get_outer() != ranges::end(_M_parent->_M_base))
> > {
> > - auto&& __inner = _M_update_inner(_M_outer_it);
> > + auto&& __inner = _M_update_inner();
> > _M_inner_it.template emplace<1>(ranges::begin(__inner));
> > _M_satisfy();
> > }
> > }
> >
> > - constexpr auto&&
> > - _M_update_inner(const _OuterIter& __x)
> > + constexpr auto&
> > + _M_update_inner()
> > {
> > + _OuterIter& __outer = _M_get_outer();
> > if constexpr (_S_ref_is_glvalue)
> > - return *__x;
> > + return __detail::__as_lvalue(*__outer);
> > else
> > - return _M_parent->_M_inner._M_emplace_deref(__x);
> > + return _M_parent->_M_inner._M_emplace_deref(__outer);
> > }
> >
> > - constexpr auto&&
> > - _M_get_inner(const _OuterIter& __x)
> > + constexpr auto&
> > + _M_get_inner()
> > {
> > if constexpr (_S_ref_is_glvalue)
> > - return *__x;
> > + return __detail::__as_lvalue(*_M_get_outer());
> > else
> > return *_M_parent->_M_inner;
> > }
> > @@ -7148,16 +7240,16 @@ namespace views::__adaptor
> > if (std::get<0>(_M_inner_it) != ranges::end(_M_parent->_M_pattern))
> > break;
> >
> > - auto&& __inner = _M_update_inner(_M_outer_it);
> > + auto&& __inner = _M_update_inner();
> > _M_inner_it.template emplace<1>(ranges::begin(__inner));
> > }
> > else
> > {
> > - auto&& __inner = _M_get_inner(_M_outer_it);
> > + auto&& __inner = _M_get_inner();
> > if (std::get<1>(_M_inner_it) != ranges::end(__inner))
> > break;
> >
> > - if (++_M_outer_it == ranges::end(_M_parent->_M_base))
> > + if (++_M_get_outer() == ranges::end(_M_parent->_M_base))
> > {
> > if constexpr (_S_ref_is_glvalue)
> > _M_inner_it.template emplace<0>();
> > @@ -7196,7 +7288,7 @@ namespace views::__adaptor
> > iter_difference_t<_InnerIter>,
> > iter_difference_t<_PatternIter>>;
> >
> > - _Iterator() requires default_initializable<_OuterIter> = default;
> > + _Iterator() = default;
> >
> > constexpr
> > _Iterator(_Iterator<!_Const> __i)
> > @@ -7306,7 +7398,7 @@ namespace views::__adaptor
> > friend constexpr bool
> > operator==(const _Iterator& __x, const _Iterator& __y)
> > requires _S_ref_is_glvalue
> > - && equality_comparable<_OuterIter> && equality_comparable<_InnerIter>
> > + && forward_range<_Base> && equality_comparable<_InnerIter>
> > { return __x._M_outer_it == __y._M_outer_it && __x._M_inner_it ==__y._M_inner_it; }
> >
> > friend constexpr common_reference_t<iter_rvalue_reference_t<_InnerIter>,
> > @@ -7373,7 +7465,7 @@ namespace views::__adaptor
> > iterator_t<__detail::__maybe_const_t<_OtherConst, _Vp>>>
> > friend constexpr bool
> > operator==(const _Iterator<_OtherConst>& __x, const _Sentinel& __y)
> > - { return __x._M_outer_it == __y._M_end; }
> > + { return __x._M_get_outer() == __y._M_end; }
> > };
> >
> > namespace views
> > diff --git a/libstdc++-v3/testsuite/std/ranges/adaptors/p2770r0.cc b/libstdc++-v3/testsuite/std/ranges/adaptors/p2770r0.cc
> > new file mode 100644
> > index 00000000000..15d71b2faa9
> > --- /dev/null
> > +++ b/libstdc++-v3/testsuite/std/ranges/adaptors/p2770r0.cc
> > @@ -0,0 +1,110 @@
> > +// { dg-options "-std=gnu++20" }
> > +// { dg-do run { target c++20 } }
> > +
> > +#include <ranges>
> > +#include <algorithm>
> > +#include <regex>
> > +#include <string_view>
> > +#include <testsuite_hooks.h>
> > +
> > +namespace ranges = std::ranges;
> > +namespace views = std::views;
> > +
> > +void
> > +test01()
> > +{
> > + // Test case from LWG 3698
> > + char const text[] = "Hello";
> > + std::regex regex{"[a-z]"};
> > +
> > + auto lower
> > + = ranges::subrange(std::cregex_iterator(ranges::begin(text),
> > + ranges::end(text),
> > + regex),
> > + std::cregex_iterator{})
> > + | views::join
> > + | views::transform([](auto const& sm) {
> > + return std::string_view(sm.first, sm.second);
> > + });
> > +
> > + VERIFY( ranges::equal(lower, (std::string_view[]){"e", "l", "l", "o"}));
> > +}
> > +
> > +void
> > +test02()
> > +{
> > +#if __cpp_lib_ranges_join_with
> > + // Analogous test case from LWG 3698 for join_with_view
> > + char const text[] = "Hello";
> > + std::regex regex{"[a-z]"};
> > +
> > + auto lower
> > + = ranges::subrange(std::cregex_iterator(ranges::begin(text),
> > + ranges::end(text),
> > + regex),
> > + std::cregex_iterator{})
> > + | views::join_with(views::empty<std::sub_match<const char*>>)
> > + | views::transform([](auto const& sm) {
> > + return std::string_view(sm.first, sm.second);
> > + });
> > +
> > + VERIFY( ranges::equal(lower, (std::string_view[]){"e", "l", "l", "o"}));
> > +#endif
> > +}
> > +
> > +void
> > +test03()
> > +{
> > + // Test case from LWG 3700
> > + auto r = views::iota(0, 5) | views::split(1);
> > + auto s = views::single(r);
> > + auto j = s | views::join;
> > + auto f = j.front();
> > +}
> > +
> > +void
> > +test04()
> > +{
> > +#if __cpp_lib_ranges_join_with
> > + // Analogous test case from LWG 3700 for join_with_view
> > + auto r = views::iota(0, 5) | views::split(1);
> > + auto s = views::single(r);
> > + auto j = s | views::join_with(views::empty<ranges::range_value_t<decltype(r)>>);
> > + auto f = j.front();
> > +#endif
> > +}
> > +
> > +void
> > +test05()
> > +{
> > + // Test case from LWG 3791
> > + std::vector<std::vector<int>> v = {{1}};
> > + auto r = v
> > + | views::transform([](auto& x) -> auto&& { return std::move(x); })
> > + | views::join;
> > + auto e = --r.end();
> > +}
> > +
> > +void
> > +test06()
> > +{
> > +#if __cpp_lib_ranges_join_with
> > + // Analogous test case from LWG 3791 for join_with_view
> > + std::vector<std::vector<int>> v = {{1}};
> > + auto r = v
> > + | views::transform([](auto& x) -> auto&& { return std::move(x); })
> > + | views::join_with(views::empty<int>);
> > + auto e = --r.end();
> > +#endif
> > +}
> > +
> > +int
> > +main()
> > +{
> > + test01();
> > + test02();
> > + test03();
> > + test04();
> > + test05();
> > + test06();
> > +}
> > --
> > 2.40.0.335.g9857273be0
> >
>
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2023-04-17 13:39 [PATCH] libstdc++: Implement P2770R0 changes to join_view / join_with_view Patrick Palka
2023-08-16 16:04 ` Patrick Palka
2023-08-16 17:28 ` Jonathan Wakely
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