Some of the range adaptors have distinct constant and non-constant
iterator/sentinel types, along with converting constructors that can convert a
non-constant iterator/sentinel to a constant iterator/sentinel. This patch adds
the missing appropriate friend declarations in order to make these converting
constructors well formed.
Strictly speaking it seems the friendship relation doesn't need to go both ways
-- we could get away with declaring e.g. friend _Iterator<false>; instead of
friend _Iterator<!_Const>; but the spec and the reference implementations all
seem to use the latter symmetric form anyway.
libstdc++-v3/ChangeLog:
* include/std/ranges (transform_view::_Iterator<_Const>): Befriend
_Iterator<!_Const>.
(transform_view::_Sentinel<_Const>): Befriend _Sentinel<!_Const>.
(take_view::_Sentinel<_Const>): Likewise.
(take_while_view::_Sentinel<_Const>): Likewise.
(split_view::_OuterIter<_Const>): Befriend _OuterIter<!_Const>.
* std/ranges/adaptors/split.cc: Augment test.
* std/ranges/adaptors/take.cc: Augment test.
* std/ranges/adaptors/take_while.cc: Augment test.
* std/ranges/adaptors/transform.cc: Augment test.
---
libstdc++-v3/include/std/ranges | 8 +++++++
.../testsuite/std/ranges/adaptors/split.cc | 14 +++++++++++
.../testsuite/std/ranges/adaptors/take.cc | 16 +++++++++++++
.../std/ranges/adaptors/take_while.cc | 17 ++++++++++++++
.../std/ranges/adaptors/transform.cc | 23 +++++++++++++++++++
5 files changed, 78 insertions(+)
diff --git a/libstdc++-v3/include/std/ranges b/libstdc++-v3/include/std/ranges
index 2e3e298adcc..2f08cfd7f16 100644
--- a/libstdc++-v3/include/std/ranges
+++ b/libstdc++-v3/include/std/ranges
@@ -1844,6 +1844,7 @@ namespace views
requires indirectly_swappable<_Base_iter>
{ return ranges::iter_swap(__x._M_current, __y._M_current); }
+ friend _Iterator<!_Const>;
friend _Sentinel<_Const>;
};
@@ -1896,6 +1897,8 @@ namespace views
operator-(const _Sentinel& __y, const _Iterator<_Const>& __x)
requires sized_sentinel_for<sentinel_t<_Base>, iterator_t<_Base>>
{ return __y.__distance_from(__x); }
+
+ friend _Sentinel<!_Const>;
};
_Vp _M_base = _Vp();
@@ -2001,6 +2004,8 @@ namespace views
friend constexpr bool operator==(const _CI& __y, const _Sentinel& __x)
{ return __y.count() == 0 || __y.base() == __x._M_end; }
+
+ friend _Sentinel<!_Const>;
};
_Vp _M_base = _Vp();
@@ -2140,6 +2145,8 @@ namespace views
friend constexpr bool
operator==(const iterator_t<_Base>& __x, const _Sentinel& __y)
{ return __y._M_end == __x || !std::__invoke(*__y._M_pred, *__x); }
+
+ friend _Sentinel<!_Const>;
};
_Vp _M_base = _Vp();
@@ -2831,6 +2838,7 @@ namespace views
operator==(const _OuterIter& __x, default_sentinel_t)
{ return __x.__at_end(); };
+ friend _OuterIter<!_Const>;
friend _InnerIter<_Const>;
};
diff --git a/libstdc++-v3/testsuite/std/ranges/adaptors/split.cc
b/libstdc++-v3/testsuite/std/ranges/adaptors/split.cc
index 52b015cf0c6..e7556725e4f 100644
--- a/libstdc++-v3/testsuite/std/ranges/adaptors/split.cc
+++ b/libstdc++-v3/testsuite/std/ranges/adaptors/split.cc
@@ -108,6 +108,19 @@ test05()
str | views::filter(not_space_p)) );
}
+void
+test06()
+{
+ std::string str = "hello world";
+ auto v = str | views::transform(std::identity{}) | views::split(' ');
+
+ // Verify that _Iterator<false> is implicitly convertible to _Iterator<true>.
+ static_assert(!std::same_as<decltype(ranges::begin(v)),
+ decltype(ranges::cbegin(v))>);
+ auto b = ranges::cbegin(v);
+ b = ranges::begin(v);
+}
+
int
main()
{
@@ -116,4 +129,5 @@ main()
test03();
test04();
test05();
+ test06();
}
diff --git a/libstdc++-v3/testsuite/std/ranges/adaptors/take.cc
b/libstdc++-v3/testsuite/std/ranges/adaptors/take.cc
index e2d2edbe0a8..c42505b44cb 100644
--- a/libstdc++-v3/testsuite/std/ranges/adaptors/take.cc
+++ b/libstdc++-v3/testsuite/std/ranges/adaptors/take.cc
@@ -19,6 +19,7 @@
// { dg-do run { target c++2a } }
#include <algorithm>
+#include <forward_list>
#include <ranges>
#include <testsuite_hooks.h>
#include <testsuite_iterators.h>
@@ -85,6 +86,20 @@ test04()
VERIFY( ranges::equal(v | views::take(5), (int[]){1,2,3}) );
}
+void
+test05()
+{
+ std::forward_list<int> x = {1,2,3,4,5};
+ auto v = x | views::transform(std::negate{}) | views::take(4);
+
+ // Verify that _Sentinel<false> is implicitly convertible to _Sentinel<true>.
+ static_assert(!ranges::common_range<decltype(v)>);
+ static_assert(!std::same_as<decltype(ranges::end(v)),
+ decltype(ranges::cend(v))>);
+ auto b = ranges::cend(v);
+ b = ranges::end(v);
+}
+
int
main()
{
@@ -92,4 +107,5 @@ main()
test02();
test03();
test04();
+ test05();
}
diff --git a/libstdc++-v3/testsuite/std/ranges/adaptors/take_while.cc
b/libstdc++-v3/testsuite/std/ranges/adaptors/take_while.cc
index b261ffd1aae..d587127b97e 100644
--- a/libstdc++-v3/testsuite/std/ranges/adaptors/take_while.cc
+++ b/libstdc++-v3/testsuite/std/ranges/adaptors/take_while.cc
@@ -19,6 +19,7 @@
// { dg-do run { target c++2a } }
#include <algorithm>
+#include <forward_list>
#include <ranges>
#include <testsuite_hooks.h>
#include <testsuite_iterators.h>
@@ -54,9 +55,25 @@ test02()
static_assert(ranges::forward_range<R>);
}
+void
+test03()
+{
+ std::forward_list<int> x = {1,2,3,4,5};
+ auto v
+ = x | views::transform(std::negate{}) | views::take_while(std::identity{});
+
+ // Verify that _Sentinel<false> is implicitly convertible to _Sentinel<true>.
+ static_assert(!ranges::common_range<decltype(v)>);
+ static_assert(!std::same_as<decltype(ranges::end(v)),
+ decltype(ranges::cend(v))>);
+ auto b = ranges::cend(v);
+ b = ranges::end(v);
+}
+
int
main()
{
test01();
test02();
+ test03();
}
diff --git a/libstdc++-v3/testsuite/std/ranges/adaptors/transform.cc
b/libstdc++-v3/testsuite/std/ranges/adaptors/transform.cc
index 178544d6378..c14e36e0cef 100644
--- a/libstdc++-v3/testsuite/std/ranges/adaptors/transform.cc
+++ b/libstdc++-v3/testsuite/std/ranges/adaptors/transform.cc
@@ -100,6 +100,28 @@ test04()
}
}
+void
+test05()
+{
+ int x[] = {1,2,3,4,5};
+ auto i = std::counted_iterator(x, 5);
+ auto r = ranges::subrange{i, std::default_sentinel};
+ auto v = r | views::transform(std::negate{});
+
+ // Verify that _Iterator<false> is implicitly convertible to _Iterator<true>.
+ static_assert(!std::same_as<decltype(ranges::begin(v)),
+ decltype(ranges::cbegin(v))>);
+ auto a = ranges::cbegin(v);
+ a = ranges::begin(v);
+
+ // Verify that _Sentinel<false> is implicitly convertible to _Sentinel<true>.
+ static_assert(!ranges::common_range<decltype(v)>);
+ static_assert(!std::same_as<decltype(ranges::end(v)),
+ decltype(ranges::cend(v))>);
+ auto b = ranges::cend(v);
+ b = ranges::end(v);
+}
+
int
main()
{
@@ -107,4 +129,5 @@ main()
test02();
test03();
test04();
+ test05();
}
--
2.25.1.377.g2d2118b814
