From 4dc8c0b62d91d239b88cc81bbb8f4fbde317fde6 Mon Sep 17 00:00:00 2001
From: Patrick Palka <ppalka@redhat.com>
Date: Tue, 18 Apr 2023 07:21:07 -0400
Subject: [PATCH] libstdc++: Fix typo in views::as_const's operator()
 [PR109525]

	PR libstdc++/109525

libstdc++-v3/ChangeLog:

	* include/std/ranges (views::_AsConst::operator()): Add
	missing const to constant_range test.
	* testsuite/std/ranges/adaptors/as_const/1.cc (test02):
	Improve formatting.  Adjust expected type of v2.
	(test03): New test.

(cherry picked from commit 4ec4ceafcc04ec7bafb1857cf6d491030440a765)
---
 libstdc++-v3/include/std/ranges                    |  2 +-
 .../testsuite/std/ranges/adaptors/as_const/1.cc    | 37 ++++++++++++++--------
 2 files changed, 24 insertions(+), 15 deletions(-)

diff --git a/libstdc++-v3/include/std/ranges b/libstdc++-v3/include/std/ranges
index 283d757..1714f3f 100644
--- a/libstdc++-v3/include/std/ranges
+++ b/libstdc++-v3/include/std/ranges
@@ -9025,7 +9025,7 @@ namespace views::__adaptor
 	  return ref_view(static_cast<const element_type&>
 			  (std::forward<_Range>(__r).base()));
 	else if constexpr (is_lvalue_reference_v<_Range>
-			   && constant_range<_Tp>
+			   && constant_range<const _Tp>
 			   && !view<_Tp>)
 	  return ref_view(static_cast<const _Tp&>(__r));
 	else
diff --git a/libstdc++-v3/testsuite/std/ranges/adaptors/as_const/1.cc b/libstdc++-v3/testsuite/std/ranges/adaptors/as_const/1.cc
index d04645f..ac1be74 100644
--- a/libstdc++-v3/testsuite/std/ranges/adaptors/as_const/1.cc
+++ b/libstdc++-v3/testsuite/std/ranges/adaptors/as_const/1.cc
@@ -5,6 +5,7 @@
 #include <algorithm>
 #include <span>
 #include <utility>
+#include <vector>
 #include <testsuite_hooks.h>
 #include <testsuite_iterators.h>
 
@@ -36,29 +37,37 @@ test01()
 constexpr bool
 test02()
 {
-  std::same_as<ranges::empty_view<const int>> auto v1
-    = views::empty<int> | views::as_const;
-
   int x[] = {1, 2, 3};
-  std::same_as<ranges::as_const_view<ranges::ref_view<int[3]>>> auto v2
-    = x | views::as_const;
-  std::same_as<ranges::ref_view<const int[3]>> auto v3
-    = std::as_const(x) | views::as_const;
-  std::same_as<ranges::ref_view<const int[3]>> auto v4
-    = std::as_const(x) | views::all | views::as_const;
-  std::same_as<std::span<const int>> auto v5
-    = std::span{x, x+3} | views::as_const;
-
-  std::same_as<ranges::as_const_view<ranges::chunk_view<ranges::ref_view<int[3]>>>> auto v6
-     = x | views::chunk(2) | views::as_const;
+  std::same_as<ranges::empty_view<const int>>
+    auto v1 = views::empty<int> | views::as_const;
+  std::same_as<ranges::ref_view<const int[3]>>
+    auto v2 = x | views::as_const;
+  std::same_as<ranges::ref_view<const int[3]>>
+    auto v3 = std::as_const(x) | views::as_const;
+  std::same_as<ranges::ref_view<const int[3]>>
+    auto v4 = std::as_const(x) | views::all | views::as_const;
+  std::same_as<std::span<const int>>
+    auto v5 = std::span{x, x+3} | views::as_const;
+  std::same_as<ranges::as_const_view<ranges::chunk_view<ranges::ref_view<int[3]>>>>
+    auto v6 = x | views::chunk(2) | views::as_const;
   VERIFY( v6.size() == 2 );
 
   return true;
 }
 
+void
+test03()
+{
+  // PR libstdc++/109525
+  std::vector<int> v;
+  std::same_as<ranges::ref_view<const std::vector<int>>>
+    auto r = views::as_const(v);
+}
+
 int
 main()
 {
   static_assert(test01());
   static_assert(test02());
+  test03();
 }
-- 
2.7.4