[PATCH 1/3] libstdc++: Fix zip_view's operator- for integer-class difference type [PR106766]

[PATCH 1/3] libstdc++: Fix zip_view's operator- for integer-class difference type [PR106766]

[Patrick Palka]

make_unsigned_t can't give us the unsigned version of an integer-class
difference type, so use __make_unsigned_like_t / __to_unsigned_like
instead.

	PR libstdc++/106766

libstdc++-v3/ChangeLog:

	* include/std/ranges (zip_view::_Iterator::operator-): Use
	__to_unsigned_like instead of make_unsigned_t.
	(zip_view::_Sentinel::operator-): Likewise.
	* testsuite/std/ranges/zip/1.cc (test04): New test.
---
 libstdc++-v3/include/std/ranges            |  8 ++++----
 libstdc++-v3/testsuite/std/ranges/zip/1.cc | 14 ++++++++++++++
 2 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/libstdc++-v3/include/std/ranges b/libstdc++-v3/include/std/ranges
index 2b5cb0531f0..2b8fec3c386 100644
--- a/libstdc++-v3/include/std/ranges
+++ b/libstdc++-v3/include/std/ranges
@@ -4657,8 +4657,8 @@ namespace views::__adaptor
 	return ranges::min({difference_type(std::get<_Is>(__x._M_current)
 					    - std::get<_Is>(__y._M_current))...},
 			   ranges::less{},
-			   [](difference_type __i) -> make_unsigned_t<difference_type> {
-			     return __i < 0 ? -__i : __i;
+			   [](difference_type __i) {
+			     return __detail::__to_unsigned_like(__i < 0 ? -__i : __i);
 			   });
       }(make_index_sequence<sizeof...(_Vs)>{});
     }
@@ -4726,8 +4726,8 @@ namespace views::__adaptor
       return [&]<size_t... _Is>(index_sequence<_Is...>) {
 	return ranges::min({_Ret(std::get<_Is>(__x._M_current) - std::get<_Is>(__y._M_end))...},
 			   ranges::less{},
-			   [](_Ret __i) -> make_unsigned_t<_Ret> {
-			     return __i < 0 ? -__i : __i;
+			   [](_Ret __i) {
+			     return __detail::__to_unsigned_like(__i < 0 ? -__i : __i);
 			   });
       }(make_index_sequence<sizeof...(_Vs)>{});
     }
diff --git a/libstdc++-v3/testsuite/std/ranges/zip/1.cc b/libstdc++-v3/testsuite/std/ranges/zip/1.cc
index 0113efdb537..f868c97cb69 100644
--- a/libstdc++-v3/testsuite/std/ranges/zip/1.cc
+++ b/libstdc++-v3/testsuite/std/ranges/zip/1.cc
@@ -102,10 +102,24 @@ test03()
   return true;
 }
 
+constexpr bool
+test04()
+{
+  // PR libstdc++/106766
+  auto r = views::zip(views::iota(__int128(0), __int128(1)));
+  auto i = r.begin();
+  auto s = r.end();
+  VERIFY( s - i == 1 );
+  VERIFY( i + 1 - i == 1 );
+
+  return true;
+}
+
 int
 main()
 {
   static_assert(test01());
   static_assert(test02());
   static_assert(test03());
+  static_assert(test04());
 }
-- 
2.37.3.518.g79f2338b37

[PATCH 2/3] libstdc++: Fix typo in adjacent_view::_Iterator [PR106798]

[Patrick Palka]

	PR libstdc++/106798

libstdc++-v3/ChangeLog:

	* include/std/ranges (adjacent_view::_Iterator::_Iterator): Fix
	typo.
	* testsuite/std/ranges/adaptors/adjacent/1.cc (test04): New test.
---
 libstdc++-v3/include/std/ranges                      |  2 +-
 .../testsuite/std/ranges/adaptors/adjacent/1.cc      | 12 ++++++++++++
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/libstdc++-v3/include/std/ranges b/libstdc++-v3/include/std/ranges
index 2b8fec3c386..37ad80ad3de 100644
--- a/libstdc++-v3/include/std/ranges
+++ b/libstdc++-v3/include/std/ranges
@@ -5239,7 +5239,7 @@ namespace views::__adaptor
       requires _Const && convertible_to<iterator_t<_Vp>, iterator_t<_Base>>
     {
       for (size_t __j = 0; __j < _Nm; ++__j)
-	_M_current[__j] = std::move(__i[__j]);
+	_M_current[__j] = std::move(__i._M_current[__j]);
     }
 
     constexpr auto
diff --git a/libstdc++-v3/testsuite/std/ranges/adaptors/adjacent/1.cc b/libstdc++-v3/testsuite/std/ranges/adaptors/adjacent/1.cc
index 9829f79364f..443c1fbf450 100644
--- a/libstdc++-v3/testsuite/std/ranges/adaptors/adjacent/1.cc
+++ b/libstdc++-v3/testsuite/std/ranges/adaptors/adjacent/1.cc
@@ -101,10 +101,22 @@ test03()
   return true;
 }
 
+constexpr bool
+test04()
+{
+  // PR libstdc++/106798
+  auto r = views::single(0) | views::lazy_split(0) | views::pairwise;
+  decltype(ranges::cend(r)) s = r.end();
+  VERIFY( r.begin() == s );
+
+  return true;
+}
+
 int
 main()
 {
   static_assert(test01());
   static_assert(test02());
   static_assert(test03());
+  static_assert(test04());
 }
-- 
2.37.3.518.g79f2338b37

[PATCH 3/3] libstdc++: Fix return type of empty zip/adjacent_transform [PR106803]

[Patrick Palka]

Tested on x86_64-pc-linux-gnu, does this series look OK for trunk?

	PR libstdc++/106803

libstdc++-v3/ChangeLog:

	* include/std/ranges (views::_ZipTransform::operator()): Fix
	return type in the empty case.
	(views::_AdjacentTransform::operator()): Likewise.
---
 libstdc++-v3/include/std/ranges | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/libstdc++-v3/include/std/ranges b/libstdc++-v3/include/std/ranges
index 37ad80ad3de..20eb4e82ac8 100644
--- a/libstdc++-v3/include/std/ranges
+++ b/libstdc++-v3/include/std/ranges
@@ -5071,7 +5071,7 @@ namespace views::__adaptor
 	operator() [[nodiscard]] (_Fp&& __f, _Ts&&... __ts) const
 	{
 	  if constexpr (sizeof...(_Ts) == 0)
-	    return views::empty<decay_t<invoke_result_t<_Fp>>>;
+	    return views::empty<decay_t<invoke_result_t<decay_t<_Fp>&>>>;
 	  else
 	    return zip_transform_view(std::forward<_Fp>(__f), std::forward<_Ts>(__ts)...);
 	}
@@ -5762,7 +5762,7 @@ namespace views::__adaptor
 	  operator() [[nodiscard]] (_Range&& __r, _Fp&& __f) const
 	  {
 	    if constexpr (_Nm == 0)
-	      return views::empty<tuple<>>;
+	      return zip_transform(std::forward<_Fp>(__f));
 	    else
 	      return adjacent_transform_view<all_t<_Range>, decay_t<_Fp>, _Nm>
 		(std::forward<_Range>(__r), std::forward<_Fp>(__f));
-- 
2.37.3.518.g79f2338b37