[libcxx-commits] [libcxx] [libc++][memory] LWG4148: `unique_ptr::operator*` should not allow dangling references (PR #214971)

Hristo Hristov via libcxx-commits libcxx-commits at lists.llvm.org
Sat Aug 8 11:44:40 PDT 2026


https://github.com/H-G-Hristov updated https://github.com/llvm/llvm-project/pull/214971

>From c7a4c8e96a1b3e667a2c836892faa83e6e6dac68 Mon Sep 17 00:00:00 2001
From: Mohamed Atef <mohamedatef1698 at gmail.com>
Date: Fri, 21 Feb 2025 20:13:33 +0200
Subject: [PATCH 1/7] [libcxx] implement LWG4148: unique_ptr::operator* should
 not allow dangling references

---
 libcxx/docs/Status/Cxx26Issues.csv            |  2 +-
 libcxx/include/__memory/unique_ptr.h          |  8 ++++++
 .../test/libcxx/memory/unique_ptr.verify.cpp  | 27 +++++++++++++++++++
 3 files changed, 36 insertions(+), 1 deletion(-)
 create mode 100644 libcxx/test/libcxx/memory/unique_ptr.verify.cpp

diff --git a/libcxx/docs/Status/Cxx26Issues.csv b/libcxx/docs/Status/Cxx26Issues.csv
index db9bf85b72d4c..c30a7be48b86e 100644
--- a/libcxx/docs/Status/Cxx26Issues.csv
+++ b/libcxx/docs/Status/Cxx26Issues.csv
@@ -103,7 +103,7 @@
 "`LWG4142 <https://wg21.link/LWG4142>`__","``format_parse_context::check_dynamic_spec`` should require at least one type","2024-11 (Wrocław)","","","`#118358 <https://github.com/llvm/llvm-project/issues/118358>`__",""
 "`LWG4144 <https://wg21.link/LWG4144>`__","Disallow ``unique_ptr<T&, D>``","2024-11 (Wrocław)","|Complete|","23","`#118359 <https://github.com/llvm/llvm-project/issues/118359>`__",""
 "`LWG4147 <https://wg21.link/LWG4147>`__","Precondition on ``inplace_vector::emplace``","2024-11 (Wrocław)","","","`#118361 <https://github.com/llvm/llvm-project/issues/118361>`__",""
-"`LWG4148 <https://wg21.link/LWG4148>`__","``unique_ptr::operator*`` should not allow dangling references","2024-11 (Wrocław)","","","`#118362 <https://github.com/llvm/llvm-project/issues/118362>`__",""
+"`LWG4148 <https://wg21.link/LWG4148>`__","``unique_ptr::operator*`` should not allow dangling references","2024-11 (Wrocław)","|Complete|","22","`#118362 <https://github.com/llvm/llvm-project/issues/118362>`__",""
 "`LWG4153 <https://wg21.link/LWG4153>`__","Fix extra ""-1"" for ``philox_engine::max()``","2024-11 (Wrocław)","","","`#118363 <https://github.com/llvm/llvm-project/issues/118363>`__",""
 "`LWG4154 <https://wg21.link/LWG4154>`__","The Mandates for ``std::packaged_task``'s constructor from a callable entity should consider decaying","2024-11 (Wrocław)","","","`#118364 <https://github.com/llvm/llvm-project/issues/118364>`__",""
 "`LWG4157 <https://wg21.link/LWG4157>`__","The resolution of LWG3465 was damaged by P2167R3","2024-11 (Wrocław)","|Complete|","20","`#118365 <https://github.com/llvm/llvm-project/issues/118365>`__",""
diff --git a/libcxx/include/__memory/unique_ptr.h b/libcxx/include/__memory/unique_ptr.h
index fcae9d84eb991..62d43bea9613d 100644
--- a/libcxx/include/__memory/unique_ptr.h
+++ b/libcxx/include/__memory/unique_ptr.h
@@ -237,6 +237,14 @@ class _LIBCPP_UNIQUE_PTR_TRIVIAL_ABI unique_ptr {
   template <class _Ptr = pointer, __enable_if_t<__can_dereference<_Ptr>, int> = 0>
   [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 __add_lvalue_reference_t<_Tp> operator*() const
       _NOEXCEPT_(_NOEXCEPT_(*std::declval<pointer>())) {
+    // TODO(LLVM-21): Remove this workaround
+#if __has_builtin(__reference_converts_from_temporary) ||                                                              \
+    (defined(_LIBCPP_CLANG_VER) &&                                                                                     \
+     ((!defined(__ANDROID__) && _LIBCPP_CLANG_VER >= 1901) || (defined(__ANDROID__) && _LIBCPP_CLANG_VER >= 2000)))
+    static_assert(
+        !__reference_converts_from_temporary(__add_lvalue_reference_t<_Tp>, decltype(*std::declval<pointer>())),
+        "Reference type _Tp must not convert from a temporary object");
+#endif
     return *__ptr_;
   }
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 pointer operator->() const _NOEXCEPT { return __ptr_; }
diff --git a/libcxx/test/libcxx/memory/unique_ptr.verify.cpp b/libcxx/test/libcxx/memory/unique_ptr.verify.cpp
new file mode 100644
index 0000000000000..6bd3d8818431f
--- /dev/null
+++ b/libcxx/test/libcxx/memory/unique_ptr.verify.cpp
@@ -0,0 +1,27 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// REQUIRES: std-at-least-c++11
+
+// <memory>
+
+#include <memory>
+
+struct deleter {
+  using pointer = long*;
+  void operator()(pointer) const {}
+};
+
+int main(int, char**) {
+  long l = 0;
+  std::unique_ptr<const int, deleter> p(&l);
+  // expected-error-re@*:* {{static assertion failed{{.*}}'!__reference_converts_from_temporary(const int &, long &)': Reference type _Tp must not convert from a temporary object}}
+  // expected-error@*:*{{returning reference to local temporary object}}
+  int i = *p; // expected-note {{requested here}}
+  return 0;
+}

>From c3297df460b0a7419abc427431adddeb7e85891c Mon Sep 17 00:00:00 2001
From: Mohamed Atef <mohamedatef1698 at gmail.com>
Date: Wed, 6 May 2026 01:29:54 +0300
Subject: [PATCH 2/7] Address comments

---
 libcxx/include/__memory/unique_ptr.h            | 8 ++------
 libcxx/test/libcxx/memory/unique_ptr.verify.cpp | 5 ++---
 2 files changed, 4 insertions(+), 9 deletions(-)

diff --git a/libcxx/include/__memory/unique_ptr.h b/libcxx/include/__memory/unique_ptr.h
index 62d43bea9613d..ff756d010a866 100644
--- a/libcxx/include/__memory/unique_ptr.h
+++ b/libcxx/include/__memory/unique_ptr.h
@@ -42,6 +42,7 @@
 #include <__type_traits/is_trivially_relocatable.h>
 #include <__type_traits/is_void.h>
 #include <__type_traits/nat.h>
+#include <__type_traits/reference_converts_from_temporary.h>
 #include <__type_traits/remove_extent.h>
 #include <__type_traits/remove_reference.h>
 #include <__type_traits/void_t.h>
@@ -237,14 +238,9 @@ class _LIBCPP_UNIQUE_PTR_TRIVIAL_ABI unique_ptr {
   template <class _Ptr = pointer, __enable_if_t<__can_dereference<_Ptr>, int> = 0>
   [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 __add_lvalue_reference_t<_Tp> operator*() const
       _NOEXCEPT_(_NOEXCEPT_(*std::declval<pointer>())) {
-    // TODO(LLVM-21): Remove this workaround
-#if __has_builtin(__reference_converts_from_temporary) ||                                                              \
-    (defined(_LIBCPP_CLANG_VER) &&                                                                                     \
-     ((!defined(__ANDROID__) && _LIBCPP_CLANG_VER >= 1901) || (defined(__ANDROID__) && _LIBCPP_CLANG_VER >= 2000)))
     static_assert(
-        !__reference_converts_from_temporary(__add_lvalue_reference_t<_Tp>, decltype(*std::declval<pointer>())),
+        !__reference_converts_from_temporary_v<__add_lvalue_reference_t<_Tp>, decltype(*std::declval<pointer>())>,
         "Reference type _Tp must not convert from a temporary object");
-#endif
     return *__ptr_;
   }
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 pointer operator->() const _NOEXCEPT { return __ptr_; }
diff --git a/libcxx/test/libcxx/memory/unique_ptr.verify.cpp b/libcxx/test/libcxx/memory/unique_ptr.verify.cpp
index 6bd3d8818431f..e9c36a643e91f 100644
--- a/libcxx/test/libcxx/memory/unique_ptr.verify.cpp
+++ b/libcxx/test/libcxx/memory/unique_ptr.verify.cpp
@@ -17,11 +17,10 @@ struct deleter {
   void operator()(pointer) const {}
 };
 
-int main(int, char**) {
+void test() {
   long l = 0;
   std::unique_ptr<const int, deleter> p(&l);
   // expected-error-re@*:* {{static assertion failed{{.*}}'!__reference_converts_from_temporary(const int &, long &)': Reference type _Tp must not convert from a temporary object}}
   // expected-error@*:*{{returning reference to local temporary object}}
-  int i = *p; // expected-note {{requested here}}
-  return 0;
+  std::ignore = *p; // expected-note {{requested here}}
 }

>From d01d32cbd363ddfd83fa14fe758e5f2a2e97300c Mon Sep 17 00:00:00 2001
From: Hristo Hristov <zingam at outlook.com>
Date: Sat, 8 Aug 2026 16:35:40 +0300
Subject: [PATCH 3/7] Apply suggestions from code review

Co-authored-by: A. Jiang <de34 at live.cn>
---
 libcxx/docs/Status/Cxx26Issues.csv              | 2 +-
 libcxx/include/__memory/unique_ptr.h            | 2 +-
 libcxx/test/libcxx/memory/unique_ptr.verify.cpp | 6 +++---
 3 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/libcxx/docs/Status/Cxx26Issues.csv b/libcxx/docs/Status/Cxx26Issues.csv
index c30a7be48b86e..1361aaa316178 100644
--- a/libcxx/docs/Status/Cxx26Issues.csv
+++ b/libcxx/docs/Status/Cxx26Issues.csv
@@ -103,7 +103,7 @@
 "`LWG4142 <https://wg21.link/LWG4142>`__","``format_parse_context::check_dynamic_spec`` should require at least one type","2024-11 (Wrocław)","","","`#118358 <https://github.com/llvm/llvm-project/issues/118358>`__",""
 "`LWG4144 <https://wg21.link/LWG4144>`__","Disallow ``unique_ptr<T&, D>``","2024-11 (Wrocław)","|Complete|","23","`#118359 <https://github.com/llvm/llvm-project/issues/118359>`__",""
 "`LWG4147 <https://wg21.link/LWG4147>`__","Precondition on ``inplace_vector::emplace``","2024-11 (Wrocław)","","","`#118361 <https://github.com/llvm/llvm-project/issues/118361>`__",""
-"`LWG4148 <https://wg21.link/LWG4148>`__","``unique_ptr::operator*`` should not allow dangling references","2024-11 (Wrocław)","|Complete|","22","`#118362 <https://github.com/llvm/llvm-project/issues/118362>`__",""
+"`LWG4148 <https://wg21.link/LWG4148>`__","``unique_ptr::operator*`` should not allow dangling references","2024-11 (Wrocław)","|Complete|","24","`#118362 <https://github.com/llvm/llvm-project/issues/118362>`__",""
 "`LWG4153 <https://wg21.link/LWG4153>`__","Fix extra ""-1"" for ``philox_engine::max()``","2024-11 (Wrocław)","","","`#118363 <https://github.com/llvm/llvm-project/issues/118363>`__",""
 "`LWG4154 <https://wg21.link/LWG4154>`__","The Mandates for ``std::packaged_task``'s constructor from a callable entity should consider decaying","2024-11 (Wrocław)","","","`#118364 <https://github.com/llvm/llvm-project/issues/118364>`__",""
 "`LWG4157 <https://wg21.link/LWG4157>`__","The resolution of LWG3465 was damaged by P2167R3","2024-11 (Wrocław)","|Complete|","20","`#118365 <https://github.com/llvm/llvm-project/issues/118365>`__",""
diff --git a/libcxx/include/__memory/unique_ptr.h b/libcxx/include/__memory/unique_ptr.h
index ff756d010a866..8c2959db8c464 100644
--- a/libcxx/include/__memory/unique_ptr.h
+++ b/libcxx/include/__memory/unique_ptr.h
@@ -240,7 +240,7 @@ class _LIBCPP_UNIQUE_PTR_TRIVIAL_ABI unique_ptr {
       _NOEXCEPT_(_NOEXCEPT_(*std::declval<pointer>())) {
     static_assert(
         !__reference_converts_from_temporary_v<__add_lvalue_reference_t<_Tp>, decltype(*std::declval<pointer>())>,
-        "Reference type _Tp must not convert from a temporary object");
+        "the returned reference must not bind to a temporary object");
     return *__ptr_;
   }
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 pointer operator->() const _NOEXCEPT { return __ptr_; }
diff --git a/libcxx/test/libcxx/memory/unique_ptr.verify.cpp b/libcxx/test/libcxx/memory/unique_ptr.verify.cpp
index e9c36a643e91f..7f6541c101ddd 100644
--- a/libcxx/test/libcxx/memory/unique_ptr.verify.cpp
+++ b/libcxx/test/libcxx/memory/unique_ptr.verify.cpp
@@ -20,7 +20,7 @@ struct deleter {
 void test() {
   long l = 0;
   std::unique_ptr<const int, deleter> p(&l);
-  // expected-error-re@*:* {{static assertion failed{{.*}}'!__reference_converts_from_temporary(const int &, long &)': Reference type _Tp must not convert from a temporary object}}
-  // expected-error@*:*{{returning reference to local temporary object}}
-  std::ignore = *p; // expected-note {{requested here}}
+// expected-error-re@*:* {{static assertion failed{{.*}}the returned reference must not bind to a temporary object}}
+  // expected-error@*:* 0-1{{returning reference to local temporary object}}
+  (void)*p; // expected-note {{requested here}}
 }

>From 88fbe1bcb01b9dc64d6035ac658d4118004c023b Mon Sep 17 00:00:00 2001
From: Hristo Hristov <hghristov.rmm at gmail.com>
Date: Sat, 8 Aug 2026 17:45:36 +0300
Subject: [PATCH 4/7] [libc++][memory] LWG4148: `unique_ptr::operator*` should
 not allow dangling references

Implements: https://wg21.link/LWG4148

Closes https://github.com/llvm/llvm-project/issues/118362
---
 libcxx/include/__memory/unique_ptr.h             |  2 +-
 .../reference_converts_from_temporary.h          | 11 +++++++----
 libcxx/test/libcxx/memory/unique_ptr.verify.cpp  | 16 +++++++++++-----
 3 files changed, 19 insertions(+), 10 deletions(-)

diff --git a/libcxx/include/__memory/unique_ptr.h b/libcxx/include/__memory/unique_ptr.h
index 8c2959db8c464..c8392d35c352f 100644
--- a/libcxx/include/__memory/unique_ptr.h
+++ b/libcxx/include/__memory/unique_ptr.h
@@ -240,7 +240,7 @@ class _LIBCPP_UNIQUE_PTR_TRIVIAL_ABI unique_ptr {
       _NOEXCEPT_(_NOEXCEPT_(*std::declval<pointer>())) {
     static_assert(
         !__reference_converts_from_temporary_v<__add_lvalue_reference_t<_Tp>, decltype(*std::declval<pointer>())>,
-        "the returned reference must not bind to a temporary object");
+        "The returned reference must not bind to a temporary object.");
     return *__ptr_;
   }
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX23 pointer operator->() const _NOEXCEPT { return __ptr_; }
diff --git a/libcxx/include/__type_traits/reference_converts_from_temporary.h b/libcxx/include/__type_traits/reference_converts_from_temporary.h
index 31479e43ee2c4..d9eeb88a5758f 100644
--- a/libcxx/include/__type_traits/reference_converts_from_temporary.h
+++ b/libcxx/include/__type_traits/reference_converts_from_temporary.h
@@ -15,10 +15,13 @@
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
 #endif
+ 
+_LIBCPP_BEGIN_NAMESPACE_STD
 
-#if _LIBCPP_STD_VER >= 23
+template <class _Tp, class _Up>
+inline const bool __reference_converts_from_temporary_v = __reference_converts_from_temporary(_Tp, _Up);
 
-_LIBCPP_BEGIN_NAMESPACE_STD
+#if _LIBCPP_STD_VER >= 23
 
 template <class _Tp, class _Up>
 struct _LIBCPP_NO_SPECIALIZATIONS reference_converts_from_temporary
@@ -28,8 +31,8 @@ template <class _Tp, class _Up>
 _LIBCPP_NO_SPECIALIZATIONS inline constexpr bool reference_converts_from_temporary_v =
     __reference_converts_from_temporary(_Tp, _Up);
 
-_LIBCPP_END_NAMESPACE_STD
-
 #endif //  _LIBCPP_STD_VER >= 23
 
+_LIBCPP_END_NAMESPACE_STD
+
 #endif // _LIBCPP___TYPE_TRAITS_REFERENCE_CONVERTS_FROM_TEMPORARY_H
diff --git a/libcxx/test/libcxx/memory/unique_ptr.verify.cpp b/libcxx/test/libcxx/memory/unique_ptr.verify.cpp
index 7f6541c101ddd..e0305e80443bb 100644
--- a/libcxx/test/libcxx/memory/unique_ptr.verify.cpp
+++ b/libcxx/test/libcxx/memory/unique_ptr.verify.cpp
@@ -12,15 +12,21 @@
 
 #include <memory>
 
-struct deleter {
+#include "test_macros.h"
+
+struct Deleter {
   using pointer = long*;
+
   void operator()(pointer) const {}
 };
 
 void test() {
   long l = 0;
-  std::unique_ptr<const int, deleter> p(&l);
-// expected-error-re@*:* {{static assertion failed{{.*}}the returned reference must not bind to a temporary object}}
-  // expected-error@*:* 0-1{{returning reference to local temporary object}}
-  (void)*p; // expected-note {{requested here}}
+  std::unique_ptr<const int, Deleter> p{&l};
+
+// expected-error-re@*:* {{static assertion failed due to requirement {{.+}}The returned reference must not bind to a temporary object.}}
+#if TEST_STD_VER >= 26
+// expected-error@*:* {{returning reference to local temporary object}}
+#endif
+  [[maybe_unused]] int i = *p;
 }

>From 3d35b0813b2faaf685e1ab60e470a24d49b83773 Mon Sep 17 00:00:00 2001
From: Hristo Hristov <hghristov.rmm at gmail.com>
Date: Sat, 8 Aug 2026 17:49:15 +0300
Subject: [PATCH 5/7] Formatting

---
 .../include/__type_traits/reference_converts_from_temporary.h   | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libcxx/include/__type_traits/reference_converts_from_temporary.h b/libcxx/include/__type_traits/reference_converts_from_temporary.h
index d9eeb88a5758f..8d879e436cab8 100644
--- a/libcxx/include/__type_traits/reference_converts_from_temporary.h
+++ b/libcxx/include/__type_traits/reference_converts_from_temporary.h
@@ -15,7 +15,7 @@
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
 #endif
- 
+
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _Tp, class _Up>

>From 43ab97c5f60f730d955e134bac51d28d4c79968c Mon Sep 17 00:00:00 2001
From: Hristo Hristov <hghristov.rmm at gmail.com>
Date: Sat, 8 Aug 2026 21:37:11 +0300
Subject: [PATCH 6/7] Addressed a review comment

---
 .../test/libcxx/memory/unique_ptr.verify.cpp  | 32 -------------------
 .../dereference.verify.cpp                    | 25 +++++++++++++--
 2 files changed, 22 insertions(+), 35 deletions(-)
 delete mode 100644 libcxx/test/libcxx/memory/unique_ptr.verify.cpp

diff --git a/libcxx/test/libcxx/memory/unique_ptr.verify.cpp b/libcxx/test/libcxx/memory/unique_ptr.verify.cpp
deleted file mode 100644
index e0305e80443bb..0000000000000
--- a/libcxx/test/libcxx/memory/unique_ptr.verify.cpp
+++ /dev/null
@@ -1,32 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-// REQUIRES: std-at-least-c++11
-
-// <memory>
-
-#include <memory>
-
-#include "test_macros.h"
-
-struct Deleter {
-  using pointer = long*;
-
-  void operator()(pointer) const {}
-};
-
-void test() {
-  long l = 0;
-  std::unique_ptr<const int, Deleter> p{&l};
-
-// expected-error-re@*:* {{static assertion failed due to requirement {{.+}}The returned reference must not bind to a temporary object.}}
-#if TEST_STD_VER >= 26
-// expected-error@*:* {{returning reference to local temporary object}}
-#endif
-  [[maybe_unused]] int i = *p;
-}
diff --git a/libcxx/test/std/utilities/smartptr/unique.ptr/unique.ptr.class/unique.ptr.observers/dereference.verify.cpp b/libcxx/test/std/utilities/smartptr/unique.ptr/unique.ptr.class/unique.ptr.observers/dereference.verify.cpp
index 46506e5622622..9610b1b7e5b98 100644
--- a/libcxx/test/std/utilities/smartptr/unique.ptr/unique.ptr.class/unique.ptr.observers/dereference.verify.cpp
+++ b/libcxx/test/std/utilities/smartptr/unique.ptr/unique.ptr.class/unique.ptr.observers/dereference.verify.cpp
@@ -16,9 +16,28 @@
 
 #include "test_macros.h"
 
-void f() {
+void test {
   std::unique_ptr<int[]> p(new int(3));
   const std::unique_ptr<int[]>& cp = p;
-  TEST_IGNORE_NODISCARD(*p);  // expected-error-re {{indirection requires pointer operand ('std::unique_ptr<int{{[ ]*}}[]>' invalid)}}
-  TEST_IGNORE_NODISCARD(*cp); // expected-error-re {{indirection requires pointer operand ('const std::unique_ptr<int{{[ ]*}}[]>' invalid)}}
+  TEST_IGNORE_NODISCARD(
+      *p); // expected-error-re {{indirection requires pointer operand ('std::unique_ptr<int{{[ ]*}}[]>' invalid)}}
+  TEST_IGNORE_NODISCARD(
+      *cp); // expected-error-re {{indirection requires pointer operand ('const std::unique_ptr<int{{[ ]*}}[]>' invalid)}}
+}
+
+void test_lwg4196 {
+  struct Deleter {
+    using pointer = long*;
+
+    void operator()(pointer) const {}
+  };
+
+  long l = 0;
+  std::unique_ptr<const int, Deleter> p{&l};
+
+  // expected-error-re@*:* {{static assertion failed due to requirement {{.+}}The returned reference must not bind to a temporary object.}}
+#if TEST_STD_VER >= 26
+  // expected-error@*:* {{returning reference to local temporary object}}
+#endif
+  [[maybe_unused]] int i = *p;
 }

>From 0a0377ab324f0c8da485a10f58a2f9f3ad14f75a Mon Sep 17 00:00:00 2001
From: Hristo Hristov <hghristov.rmm at gmail.com>
Date: Sat, 8 Aug 2026 21:44:15 +0300
Subject: [PATCH 7/7] Fixes

---
 .../unique.ptr.observers/dereference.verify.cpp   | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/libcxx/test/std/utilities/smartptr/unique.ptr/unique.ptr.class/unique.ptr.observers/dereference.verify.cpp b/libcxx/test/std/utilities/smartptr/unique.ptr/unique.ptr.class/unique.ptr.observers/dereference.verify.cpp
index 9610b1b7e5b98..7902448f56f75 100644
--- a/libcxx/test/std/utilities/smartptr/unique.ptr/unique.ptr.class/unique.ptr.observers/dereference.verify.cpp
+++ b/libcxx/test/std/utilities/smartptr/unique.ptr/unique.ptr.class/unique.ptr.observers/dereference.verify.cpp
@@ -16,16 +16,17 @@
 
 #include "test_macros.h"
 
-void test {
+void test() {
   std::unique_ptr<int[]> p(new int(3));
   const std::unique_ptr<int[]>& cp = p;
-  TEST_IGNORE_NODISCARD(
-      *p); // expected-error-re {{indirection requires pointer operand ('std::unique_ptr<int{{[ ]*}}[]>' invalid)}}
-  TEST_IGNORE_NODISCARD(
-      *cp); // expected-error-re {{indirection requires pointer operand ('const std::unique_ptr<int{{[ ]*}}[]>' invalid)}}
+
+  // expected-error-re at +1 {{indirection requires pointer operand ('std::unique_ptr<int{{[ ]*}}[]>' invalid)}}
+  TEST_IGNORE_NODISCARD(*p);
+  // expected-error-re at +1 {{indirection requires pointer operand ('const std::unique_ptr<int{{[ ]*}}[]>' invalid)}}
+  TEST_IGNORE_NODISCARD(*cp);
 }
 
-void test_lwg4196 {
+void test_lwg4196() {
   struct Deleter {
     using pointer = long*;
 
@@ -33,7 +34,7 @@ void test_lwg4196 {
   };
 
   long l = 0;
-  std::unique_ptr<const int, Deleter> p{&l};
+  std::unique_ptr<const int, Deleter> p(&l);
 
   // expected-error-re@*:* {{static assertion failed due to requirement {{.+}}The returned reference must not bind to a temporary object.}}
 #if TEST_STD_VER >= 26



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