[PATCH 1/2] libstdc++: Forward second argument of views::iota using the correct type

[Patrick Palka]

We are forwarding the second argument of views::iota using the wrong type,
causing compiling errors when calling it with a value and bound of different
types, like in the test case below.

libstdc++-v3/ChangeLog:

        * include/std/ranges (views::_Iota::operator()): Forward __f using the
        correct type.
        * testsuite/std/ranges/access/ssize.cc (test06): Don't call views::iota
        with integers of different signedness, to appease iota_view's deduction
        guide.
        * testsuite/std/ranges/iota/iota_view.cc: Augment test.
---
 libstdc++-v3/include/std/ranges                 |  2 +-
 .../testsuite/std/ranges/access/ssize.cc        |  2 +-
 .../testsuite/std/ranges/iota/iota_view.cc      | 17 +++++++++++++++++
 3 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/libstdc++-v3/include/std/ranges b/libstdc++-v3/include/std/ranges
index 7a66491f2e4..1b2bf448e9c 100644
--- a/libstdc++-v3/include/std/ranges
+++ b/libstdc++-v3/include/std/ranges
@@ -933,7 +933,7 @@ namespace views
     template<typename _Tp, typename _Up>
       constexpr auto
       operator()(_Tp&& __e, _Up&& __f) const
-      { return iota_view{std::forward<_Tp>(__e), std::forward<_Tp>(__f)}; }
+      { return iota_view{std::forward<_Tp>(__e), std::forward<_Up>(__f)}; }
   };
 
   inline constexpr _Iota iota{};
diff --git a/libstdc++-v3/testsuite/std/ranges/access/ssize.cc 
b/libstdc++-v3/testsuite/std/ranges/access/ssize.cc
index 5aa05be8f20..31092056c76 100644
--- a/libstdc++-v3/testsuite/std/ranges/access/ssize.cc
+++ b/libstdc++-v3/testsuite/std/ranges/access/ssize.cc
@@ -80,7 +80,7 @@ test05()
 void
 test06()
 {
-  auto i = std::views::iota(1ull, 5);
+  auto i = std::views::iota(1ull, 5u);
   auto s = std::ranges::ssize(i);
   using R = std::ranges::range_difference_t<decltype(i)>;
   static_assert( std::same_as<decltype(s), R> );
diff --git a/libstdc++-v3/testsuite/std/ranges/iota/iota_view.cc 
b/libstdc++-v3/testsuite/std/ranges/iota/iota_view.cc
index 798e745d3f0..65d166fbd3b 100644
--- a/libstdc++-v3/testsuite/std/ranges/iota/iota_view.cc
+++ b/libstdc++-v3/testsuite/std/ranges/iota/iota_view.cc
@@ -61,10 +61,27 @@ test03()
   VERIFY( it == v.end() );
 }
 
+void
+test04()
+{
+  int x[] = {1,2,3};
+  auto v = std::ranges::views::iota(std::counted_iterator(x, 3),
+                                   std::default_sentinel);
+  auto it = v.begin();
+  VERIFY( (*it).base() == x );
+  ++it;
+  VERIFY( (*it).base() == x+1 );
+  ++it;
+  VERIFY( (*it).base() == x+2 );
+  ++it;
+  VERIFY( it == v.end() );
+}
+
 int
 main()
 {
   test01();
   test02();
   test03();
+  test04();
 }
-- 
2.25.1.291.ge68e29171c