[libcxx-commits] [libcxx] 9f5efd5 - [libc++] Correct `optional<T&>` implementation (#174537)

via libcxx-commits libcxx-commits at lists.llvm.org
Fri Jan 9 00:33:15 PST 2026


Author: William Tran-Viet
Date: 2026-01-09T16:33:10+08:00
New Revision: 9f5efd5d03710480e5bf29ffa79d556d0d90f456

URL: https://github.com/llvm/llvm-project/commit/9f5efd5d03710480e5bf29ffa79d556d0d90f456
DIFF: https://github.com/llvm/llvm-project/commit/9f5efd5d03710480e5bf29ffa79d556d0d90f456.diff

LOG: [libc++] Correct `optional<T&>` implementation (#174537)

Resolves #174350

- Several issues were found in the current implementation of
`optional<T&>`
- `value()`, `operator*()`, `and_then()`, `transform()`, `operator->()`
still provided their ref-qualified versions for rvalues and `const&`.
- Using the listed methods on an rvalue `optional<T&>` would cause a
compile failure due to a mismatch in return types.
- On the latter, `operator*`, `operator->` would return `const` for a
`optional<T&>`, which is an incorrect deep const.
- A few constructors were missing (`optional<U>&`), and most
constructors relevant to `optional<T&>` were missing `noexcept`
- Constructors and `emplace` were not correctly constructing a `T&` as
specified in _`convert-ref-init-val`_
- Also corrects the behavior of `value_or` which should return
`remove_cv_t<T>` (in our case `decay_t<_Tp>`)
- Add several test cases to verify behavior, update `value_or` tests

Added: 
    libcxx/test/std/utilities/optional/optional.object/optional.object.assign/emplace.verify.cpp
    libcxx/test/std/utilities/optional/optional.object/optional_helper_types.h

Modified: 
    libcxx/include/optional
    libcxx/test/libcxx/utilities/optional/optional.object/optional.object.observe/value_or.compile.pass.cpp
    libcxx/test/std/utilities/optional/optional.monadic/and_then.pass.cpp
    libcxx/test/std/utilities/optional/optional.monadic/or_else.pass.cpp
    libcxx/test/std/utilities/optional/optional.monadic/transform.pass.cpp
    libcxx/test/std/utilities/optional/optional.object/optional.object.assign/assign_value.pass.cpp
    libcxx/test/std/utilities/optional/optional.object/optional.object.assign/const_optional_U.pass.cpp
    libcxx/test/std/utilities/optional/optional.object/optional.object.assign/copy.pass.cpp
    libcxx/test/std/utilities/optional/optional.object/optional.object.assign/emplace.pass.cpp
    libcxx/test/std/utilities/optional/optional.object/optional.object.assign/move.pass.cpp
    libcxx/test/std/utilities/optional/optional.object/optional.object.assign/nullopt_t.pass.cpp
    libcxx/test/std/utilities/optional/optional.object/optional.object.assign/optional_U.pass.cpp
    libcxx/test/std/utilities/optional/optional.object/optional.object.ctor/U.pass.cpp
    libcxx/test/std/utilities/optional/optional.object/optional.object.ctor/const_optional_U.pass.cpp
    libcxx/test/std/utilities/optional/optional.object/optional.object.ctor/copy.pass.cpp
    libcxx/test/std/utilities/optional/optional.object/optional.object.ctor/in_place_t.pass.cpp
    libcxx/test/std/utilities/optional/optional.object/optional.object.ctor/move.pass.cpp
    libcxx/test/std/utilities/optional/optional.object/optional.object.ctor/optional_U.pass.cpp
    libcxx/test/std/utilities/optional/optional.object/optional.object.ctor/ref_constructs_from_temporary.verify.cpp
    libcxx/test/std/utilities/optional/optional.object/optional.object.mod/reset.pass.cpp
    libcxx/test/std/utilities/optional/optional.object/optional.object.observe/bool.pass.cpp
    libcxx/test/std/utilities/optional/optional.object/optional.object.observe/dereference.pass.cpp
    libcxx/test/std/utilities/optional/optional.object/optional.object.observe/dereference_const.pass.cpp
    libcxx/test/std/utilities/optional/optional.object/optional.object.observe/dereference_const_rvalue.pass.cpp
    libcxx/test/std/utilities/optional/optional.object/optional.object.observe/dereference_rvalue.pass.cpp
    libcxx/test/std/utilities/optional/optional.object/optional.object.observe/has_value.pass.cpp
    libcxx/test/std/utilities/optional/optional.object/optional.object.observe/op_arrow.pass.cpp
    libcxx/test/std/utilities/optional/optional.object/optional.object.observe/op_arrow_const.pass.cpp
    libcxx/test/std/utilities/optional/optional.object/optional.object.observe/value_const.pass.cpp
    libcxx/test/std/utilities/optional/optional.object/optional.object.observe/value_const_rvalue.pass.cpp
    libcxx/test/std/utilities/optional/optional.object/optional.object.observe/value_or.pass.cpp
    libcxx/test/std/utilities/optional/optional.object/optional.object.swap/swap.pass.cpp

Removed: 
    


################################################################################
diff  --git a/libcxx/include/optional b/libcxx/include/optional
index 568c86556d156..91c0167ae8f06 100644
--- a/libcxx/include/optional
+++ b/libcxx/include/optional
@@ -477,14 +477,21 @@ struct __optional_storage_base : __optional_destruct_base<_Tp> {
     }
   }
 
-  template <class _Up>
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void __assign_from_val(_Up&& __val) {
-    this->__get() = std::forward<_Up>(__val);
-  }
-
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void __swap(__optional_storage_base& __rhs) {
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void
+  __swap(__optional_storage_base& __rhs) noexcept(is_nothrow_move_constructible_v<_Tp> && is_nothrow_swappable_v<_Tp>) {
     using std::swap;
-    swap(this->__get(), __rhs.__get());
+    if (this->has_value() == __rhs.has_value()) {
+      if (this->has_value())
+        swap(this->__get(), __rhs.__get());
+    } else {
+      if (this->has_value()) {
+        __rhs.__construct(std::move(this->__get()));
+        this->reset();
+      } else {
+        this->__construct(std::move(__rhs.__get()));
+        __rhs.reset();
+      }
+    }
   }
 };
 
@@ -496,21 +503,25 @@ struct __optional_storage_base<_Tp, true> {
 
   _LIBCPP_HIDE_FROM_ABI constexpr __optional_storage_base() noexcept : __value_(nullptr) {}
 
+  template <class _Up>
+  _LIBCPP_HIDE_FROM_ABI constexpr void __convert_init_ref_val(_Up&& __val) noexcept {
+    _Tp& __r(std::forward<_Up>(__val));
+    __value_ = std::addressof(__r);
+  }
+
   template <class _UArg>
-  _LIBCPP_HIDE_FROM_ABI constexpr explicit __optional_storage_base(in_place_t, _UArg&& __uarg)
-      : __value_(std::addressof(__uarg)) {
+  _LIBCPP_HIDE_FROM_ABI constexpr explicit __optional_storage_base(in_place_t, _UArg&& __uarg) {
     static_assert(!__reference_constructs_from_temporary_v<_Tp, _UArg>,
                   "Attempted to construct a reference element in optional from a "
                   "possible temporary");
+    __convert_init_ref_val(std::forward<_UArg>(__uarg));
   }
 
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void reset() noexcept { __value_ = nullptr; }
 
   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr bool has_value() const noexcept { return __value_ != nullptr; }
 
-  _LIBCPP_HIDE_FROM_ABI constexpr value_type& __get() const& noexcept { return *__value_; }
-
-  _LIBCPP_HIDE_FROM_ABI constexpr value_type&& __get() const&& noexcept { return std::forward<value_type>(*__value_); }
+  _LIBCPP_HIDE_FROM_ABI constexpr value_type& __get() const noexcept { return *__value_; }
 
   template <class _UArg>
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void __construct(_UArg&& __val) {
@@ -518,7 +529,7 @@ struct __optional_storage_base<_Tp, true> {
     static_assert(!__reference_constructs_from_temporary_v<_Tp, _UArg>,
                   "Attempted to construct a reference element in tuple from a "
                   "possible temporary");
-    __value_ = std::addressof(__val);
+    __convert_init_ref_val(std::forward<_UArg>(__val));
   }
 
   template <class _That>
@@ -540,11 +551,6 @@ struct __optional_storage_base<_Tp, true> {
     }
   }
 
-  template <class _Up>
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void __assign_from_val(_Up&& __val) noexcept {
-    __value_ = std::addressof(__val);
-  }
-
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void __swap(__optional_storage_base& __rhs) noexcept {
     std::swap(__value_, __rhs.__value_);
   }
@@ -706,7 +712,7 @@ struct __optional_iterator {};
 #    if _LIBCPP_STD_VER >= 26
 
 template <class _Tp>
-struct __optional_iterator<_Tp, enable_if_t<!is_lvalue_reference_v<_Tp>>> {
+struct __optional_iterator<_Tp, enable_if_t<is_object_v<_Tp>>> {
 private:
   using __pointer _LIBCPP_NODEBUG       = add_pointer_t<_Tp>;
   using __const_pointer _LIBCPP_NODEBUG = add_pointer_t<const _Tp>;
@@ -909,38 +915,61 @@ public:
       : __base(in_place, __il, std::forward<_Args>(__args)...) {}
 
   template <class _Up = _Tp, enable_if_t<_CheckOptionalArgsCtor<_Up>::template __enable_implicit<_Up>(), int> = 0>
-  _LIBCPP_HIDE_FROM_ABI constexpr optional(_Up&& __v) : __base(in_place, std::forward<_Up>(__v)) {}
+  _LIBCPP_HIDE_FROM_ABI constexpr optional(_Up&& __v)
+#    if _LIBCPP_STD_VER >= 26
+      noexcept(is_lvalue_reference_v<_Tp> && is_nothrow_constructible_v<_Tp&, _Up>)
+#    endif
+      : __base(in_place, std::forward<_Up>(__v)) {
+  }
 
   template <class _Up                                                                        = remove_cv_t<_Tp>,
             enable_if_t<_CheckOptionalArgsCtor<_Up>::template __enable_explicit<_Up>(), int> = 0>
-  _LIBCPP_HIDE_FROM_ABI constexpr explicit optional(_Up&& __v) : __base(in_place, std::forward<_Up>(__v)) {}
+  _LIBCPP_HIDE_FROM_ABI constexpr explicit optional(_Up&& __v)
+#    if _LIBCPP_STD_VER >= 26
+      noexcept(is_lvalue_reference_v<_Tp> && is_nothrow_constructible_v<_Tp&, _Up>)
+#    endif
+      : __base(in_place, std::forward<_Up>(__v)) {
+  }
 
   // LWG2756: conditionally explicit conversion from const optional<_Up>&
   template <class _Up, enable_if_t<_CheckOptionalLikeCtor<_Up, _Up const&>::template __enable_implicit<_Up>(), int> = 0>
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 optional(const optional<_Up>& __v) {
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 optional(const optional<_Up>& __v)
+#    if _LIBCPP_STD_VER >= 26
+      noexcept(is_lvalue_reference_v<_Tp> && is_nothrow_constructible_v<_Tp&, _Up&>)
+#    endif
+  {
     this->__construct_from(__v);
   }
   template <class _Up, enable_if_t<_CheckOptionalLikeCtor<_Up, _Up const&>::template __enable_explicit<_Up>(), int> = 0>
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 explicit optional(const optional<_Up>& __v) {
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 explicit optional(const optional<_Up>& __v)
+#    if _LIBCPP_STD_VER >= 26
+      noexcept(is_lvalue_reference_v<_Tp> && is_nothrow_constructible_v<_Tp&, _Up&>)
+#    endif
+  {
     this->__construct_from(__v);
   }
 
   // LWG2756: conditionally explicit conversion from optional<_Up>&&
   template <class _Up, enable_if_t<_CheckOptionalLikeCtor<_Up, _Up&&>::template __enable_implicit<_Up>(), int> = 0>
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 optional(optional<_Up>&& __v) {
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 optional(optional<_Up>&& __v)
+#    if _LIBCPP_STD_VER >= 26
+      noexcept(is_lvalue_reference_v<_Tp> && is_nothrow_constructible_v<_Tp&, _Up>)
+#    endif
+  {
     this->__construct_from(std::move(__v));
   }
   template <class _Up, enable_if_t<_CheckOptionalLikeCtor<_Up, _Up&&>::template __enable_explicit<_Up>(), int> = 0>
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 explicit optional(optional<_Up>&& __v) {
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 explicit optional(optional<_Up>&& __v)
+#    if _LIBCPP_STD_VER >= 26
+      noexcept(is_lvalue_reference_v<_Tp> && is_nothrow_constructible_v<_Tp&, _Up>)
+#    endif
+  {
     this->__construct_from(std::move(__v));
   }
 
-  // deleted optional<T&> constructors
+  // deleted optional<T&> constructors and additional optional<T&> constructors
 #    if _LIBCPP_STD_VER >= 26
-  template <class _Up, class... _Args, enable_if_t<is_constructible_v<_Tp, initializer_list<_Up>&, _Args...>, int> = 0>
-    requires __libcpp_opt_ref_ctor_deleted<_Up>
-  explicit optional(in_place_t, initializer_list<_Up>, _Args&&...) = delete;
-
+  // optional(U&&)
   template <class _Up = _Tp, enable_if_t<_CheckOptionalArgsCtor<_Up>::template __enable_implicit<_Up>(), int> = 0>
     requires __libcpp_opt_ref_ctor_deleted<_Up>
   optional(_Up&&) = delete;
@@ -950,6 +979,21 @@ public:
     requires __libcpp_opt_ref_ctor_deleted<_Up>
   explicit optional(_Up&&) = delete;
 
+  // optional(optional<U>& rhs)
+  template <class _Up>
+    requires(!__libcpp_opt_ref_ctor_deleted<_Up>) && (!is_same_v<remove_cvref_t<_Tp>, optional<_Up>>) &&
+            (!is_same_v<_Tp&, _Up>) && is_constructible_v<_Tp&, _Up&>
+  _LIBCPP_HIDE_FROM_ABI constexpr explicit(!is_convertible_v<_Up&, _Tp&>)
+      optional(optional<_Up>& __rhs) noexcept(is_nothrow_constructible_v<_Tp&, _Up&>) {
+    this->__construct_from(__rhs);
+  }
+
+  template <class _Up>
+    requires __libcpp_opt_ref_ctor_deleted<_Up> && (!is_same_v<remove_cvref_t<_Tp>, optional<_Up>>) &&
+                 (!is_same_v<_Tp&, _Up>) && is_constructible_v<_Tp&, _Up&>
+  constexpr explicit optional(optional<_Up>& __rhs) noexcept = delete;
+
+  // optional(const optional<U>&)
   template <class _Up, enable_if_t<_CheckOptionalLikeCtor<_Up, _Up const&>::template __enable_implicit<_Up>(), int> = 0>
     requires __libcpp_opt_ref_ctor_deleted<_Up>
   optional(const optional<_Up>&) = delete;
@@ -958,6 +1002,7 @@ public:
     requires __libcpp_opt_ref_ctor_deleted<_Up>
   explicit optional(const optional<_Up>&) = delete;
 
+  // optional(optional<U>&&)
   template <class _Up, enable_if_t<_CheckOptionalLikeCtor<_Up, _Up&&>::template __enable_implicit<_Up>(), int> = 0>
     requires __libcpp_opt_ref_ctor_deleted<_Up>
   optional(optional<_Up>&&) = delete;
@@ -965,6 +1010,20 @@ public:
   template <class _Up, enable_if_t<_CheckOptionalLikeCtor<_Up, _Up&&>::template __enable_explicit<_Up>(), int> = 0>
     requires __libcpp_opt_ref_ctor_deleted<_Up>
   explicit optional(optional<_Up>&&) = delete;
+
+  // optional(const optional<U>&&)
+  template <class _Up>
+    requires(!__libcpp_opt_ref_ctor_deleted<_Up>) && (!is_same_v<remove_cvref_t<_Tp>, optional<_Up>>) &&
+            (!is_same_v<_Tp&, _Up>) && is_constructible_v<_Tp&, _Up>
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 explicit(!is_convertible_v<const _Up, _Tp&>)
+      optional(const optional<_Up>&& __v) noexcept(is_nothrow_constructible_v<_Tp&, const _Up>) {
+    this->__construct_from(std::move(__v));
+  }
+
+  template <class _Up>
+    requires __libcpp_opt_ref_ctor_deleted<_Up> && (!is_same_v<remove_cvref_t<_Tp>, optional<_Up>>) &&
+                 (!is_same_v<_Tp&, _Up>) && is_constructible_v<_Tp&, _Up>
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 optional(const optional<_Up>&& __v) noexcept = delete;
 #    endif
 
 #    if _LIBCPP_STD_VER >= 23
@@ -989,11 +1048,12 @@ public:
             enable_if_t<_And<_IsNotSame<__remove_cvref_t<_Up>, optional>,
                              _Or<_IsNotSame<__remove_cvref_t<_Up>, _Tp>, _Not<is_scalar<_Tp>>>,
                              is_constructible<_Tp, _Up>,
-                             is_assignable<_Tp&, _Up>>::value,
+                             is_assignable<_Tp&, _Up>,
+                             is_object<_Tp>>::value,
                         int> = 0>
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 optional& operator=(_Up&& __v) {
     if (this->has_value())
-      this->__assign_from_val(std::forward<_Up>(__v));
+      this->__get() = std::forward<_Up>(__v);
     else
       this->__construct(std::forward<_Up>(__v));
     return *this;
@@ -1013,8 +1073,12 @@ public:
     return *this;
   }
 
-  template <class... _Args, enable_if_t<is_constructible_v<_Tp, _Args...>, int> = 0>
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _Tp& emplace(_Args&&... __args) {
+  template <class... _Args, enable_if_t<__is_constructible_for_optional_v<_Tp, _Args...>, int> = 0>
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _Tp& emplace(_Args&&... __args)
+#    if _LIBCPP_STD_VER >= 26
+      noexcept(is_lvalue_reference_v<_Tp> && is_nothrow_constructible_v<_Tp, _Args...>)
+#    endif
+  {
     reset();
     this->__construct(std::forward<_Args>(__args)...);
     return this->__get();
@@ -1022,60 +1086,72 @@ public:
 
   template <class _Up,
             class... _Args,
-            enable_if_t<is_constructible_v<_Tp, initializer_list<_Up>&, _Args...>
-#    if _LIBCPP_STD_VER >= 26
-                            && !reference_constructs_from_temporary_v<_Tp&, _Up>
-#    endif
-                        ,
-                        int> = 0>
+            enable_if_t<__is_constructible_for_optional_initializer_list_v<_Tp, _Up, _Args...>, int> = 0>
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _Tp& emplace(initializer_list<_Up> __il, _Args&&... __args) {
     reset();
     this->__construct(__il, std::forward<_Args>(__args)...);
     return this->__get();
   }
 
-  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void
-  swap(optional& __opt) noexcept(is_nothrow_move_constructible_v<_Tp> && is_nothrow_swappable_v<_Tp>) {
-    if (this->has_value() == __opt.has_value()) {
-      if (this->has_value())
-        this->__swap(__opt);
-    } else {
-      if (this->has_value()) {
-        __opt.__construct(std::move(this->__get()));
-        reset();
-      } else {
-        this->__construct(std::move(__opt.__get()));
-        __opt.reset();
-      }
-    }
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void swap(optional& __opt) noexcept(
+      (is_nothrow_move_constructible_v<_Tp> && is_nothrow_swappable_v<_Tp>)
+#    if _LIBCPP_STD_VER >= 26
+      || is_lvalue_reference_v<_Tp>
+#    endif
+  ) {
+    this->__swap(__opt);
   }
 
-  _LIBCPP_HIDE_FROM_ABI constexpr add_pointer_t<_Tp const> operator->() const noexcept {
+  _LIBCPP_HIDE_FROM_ABI constexpr add_pointer_t<_Tp const> operator->() const noexcept
+#    if _LIBCPP_STD_VER >= 26
+    requires(is_object_v<_Tp>)
+#    endif
+  {
     _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(this->has_value(), "optional operator-> called on a disengaged value");
     return std::addressof(this->__get());
   }
 
-  _LIBCPP_HIDE_FROM_ABI constexpr add_pointer_t<_Tp> operator->() noexcept {
+  _LIBCPP_HIDE_FROM_ABI constexpr add_pointer_t<_Tp> operator->() noexcept
+#    if _LIBCPP_STD_VER >= 26
+    requires(is_object_v<_Tp>)
+#    endif
+  {
     _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(this->has_value(), "optional operator-> called on a disengaged value");
     return std::addressof(this->__get());
   }
 
-  [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr const _Tp& operator*() const& noexcept {
+  [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr const _Tp& operator*() const& noexcept
+#    if _LIBCPP_STD_VER >= 26
+    requires(is_object_v<_Tp>)
+#    endif
+  {
     _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(this->has_value(), "optional operator* called on a disengaged value");
     return this->__get();
   }
 
-  [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr _Tp& operator*() & noexcept {
+  [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr _Tp& operator*() & noexcept
+#    if _LIBCPP_STD_VER >= 26
+    requires(is_object_v<_Tp>)
+#    endif
+  {
     _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(this->has_value(), "optional operator* called on a disengaged value");
     return this->__get();
   }
 
-  [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr _Tp&& operator*() && noexcept {
+  [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr _Tp&& operator*() && noexcept
+#    if _LIBCPP_STD_VER >= 26
+    requires(is_object_v<_Tp>)
+#    endif
+  {
     _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(this->has_value(), "optional operator* called on a disengaged value");
     return std::move(this->__get());
   }
 
-  [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr const _Tp&& operator*() const&& noexcept {
+  [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr const _Tp&& operator*() const&& noexcept
+#    if _LIBCPP_STD_VER >= 26
+    requires(is_object_v<_Tp>)
+#    endif
+  {
     _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(this->has_value(), "optional operator* called on a disengaged value");
     return std::move(this->__get());
   }
@@ -1085,25 +1161,41 @@ public:
   using __base::__get;
   using __base::has_value;
 
-  [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr _Tp const& value() const& {
+  [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr _Tp const& value() const&
+#    if _LIBCPP_STD_VER >= 26
+    requires(is_object_v<_Tp>)
+#    endif
+  {
     if (!this->has_value())
       std::__throw_bad_optional_access();
     return this->__get();
   }
 
-  [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr _Tp& value() & {
+  [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr _Tp& value() &
+#    if _LIBCPP_STD_VER >= 26
+    requires(is_object_v<_Tp>)
+#    endif
+  {
     if (!this->has_value())
       std::__throw_bad_optional_access();
     return this->__get();
   }
 
-  [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr _Tp&& value() && {
+  [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr _Tp&& value() &&
+#    if _LIBCPP_STD_VER >= 26
+    requires(is_object_v<_Tp>)
+#    endif
+  {
     if (!this->has_value())
       std::__throw_bad_optional_access();
     return std::move(this->__get());
   }
 
-  [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr _Tp const&& value() const&& {
+  [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr _Tp const&& value() const&&
+#    if _LIBCPP_STD_VER >= 26
+    requires(is_object_v<_Tp>)
+#    endif
+  {
     if (!this->has_value())
       std::__throw_bad_optional_access();
     return std::move(this->__get());
@@ -1111,8 +1203,7 @@ public:
 
   template <class _Up = remove_cv_t<_Tp>>
 #    if _LIBCPP_STD_VER >= 26
-    requires(!(is_lvalue_reference_v<_Tp> && is_function_v<__libcpp_remove_reference_t<_Tp>>) &&
-             !(is_lvalue_reference_v<_Tp> && is_array_v<__libcpp_remove_reference_t<_Tp>>))
+    requires(is_object_v<_Tp>)
 #    endif
   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr _Tp value_or(_Up&& __v) const& {
     static_assert(is_copy_constructible_v<_Tp>, "optional<T>::value_or: T must be copy constructible");
@@ -1122,7 +1213,7 @@ public:
 
   template <class _Up = remove_cv_t<_Tp>>
 #    if _LIBCPP_STD_VER >= 26
-    requires(!is_lvalue_reference_v<_Tp>)
+    requires(is_object_v<_Tp>)
 #    endif
   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr _Tp value_or(_Up&& __v) && {
     static_assert(is_move_constructible_v<_Tp>, "optional<T>::value_or: T must be move constructible");
@@ -1130,19 +1221,11 @@ public:
     return this->has_value() ? std::move(this->__get()) : static_cast<_Tp>(std::forward<_Up>(__v));
   }
 
-#    if _LIBCPP_STD_VER >= 26
-  template <class _Up = remove_cv_t<_Tp>>
-    requires(is_lvalue_reference_v<_Tp> &&
-             !(is_function_v<__libcpp_remove_reference_t<_Tp>> || is_array_v<__libcpp_remove_reference_t<_Tp>>))
-  [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr _Tp value_or(_Up&& __v) && {
-    static_assert(is_move_constructible_v<_Tp>, "optional<T>::value_or: T must be move constructible");
-    static_assert(is_convertible_v<_Up, _Tp>, "optional<T>::value_or: U must be convertible to T");
-    return this->has_value() ? this->__get() : static_cast<_Tp>(std::forward<_Up>(__v));
-  }
-#    endif
-
 #    if _LIBCPP_STD_VER >= 23
   template <class _Func>
+#      if _LIBCPP_STD_VER >= 26
+    requires(is_object_v<_Tp>)
+#      endif
   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto and_then(_Func&& __f) & {
     using _Up = invoke_result_t<_Func, _Tp&>;
     static_assert(__is_std_optional<remove_cvref_t<_Up>>::value,
@@ -1153,6 +1236,9 @@ public:
   }
 
   template <class _Func>
+#      if _LIBCPP_STD_VER >= 26
+    requires(is_object_v<_Tp>)
+#      endif
   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto and_then(_Func&& __f) const& {
     using _Up = invoke_result_t<_Func, const _Tp&>;
     static_assert(__is_std_optional<remove_cvref_t<_Up>>::value,
@@ -1163,6 +1249,9 @@ public:
   }
 
   template <class _Func>
+#      if _LIBCPP_STD_VER >= 26
+    requires(is_object_v<_Tp>)
+#      endif
   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto and_then(_Func&& __f) && {
     using _Up = invoke_result_t<_Func, _Tp&&>;
     static_assert(__is_std_optional<remove_cvref_t<_Up>>::value,
@@ -1173,6 +1262,9 @@ public:
   }
 
   template <class _Func>
+#      if _LIBCPP_STD_VER >= 26
+    requires(is_object_v<_Tp>)
+#      endif
   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto and_then(_Func&& __f) const&& {
     using _Up = invoke_result_t<_Func, const _Tp&&>;
     static_assert(__is_std_optional<remove_cvref_t<_Up>>::value,
@@ -1183,6 +1275,9 @@ public:
   }
 
   template <class _Func>
+#      if _LIBCPP_STD_VER >= 26
+    requires(is_object_v<_Tp>)
+#      endif
   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto transform(_Func&& __f) & {
     using _Up = remove_cv_t<invoke_result_t<_Func, _Tp&>>;
     static_assert(!is_array_v<_Up>, "Result of f(value()) should not be an Array");
@@ -1195,6 +1290,9 @@ public:
   }
 
   template <class _Func>
+#      if _LIBCPP_STD_VER >= 26
+    requires(is_object_v<_Tp>)
+#      endif
   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto transform(_Func&& __f) const& {
     using _Up = remove_cv_t<invoke_result_t<_Func, const _Tp&>>;
     static_assert(!is_array_v<_Up>, "Result of f(value()) should not be an Array");
@@ -1207,6 +1305,9 @@ public:
   }
 
   template <class _Func>
+#      if _LIBCPP_STD_VER >= 26
+    requires(is_object_v<_Tp>)
+#      endif
   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto transform(_Func&& __f) && {
     using _Up = remove_cv_t<invoke_result_t<_Func, _Tp&&>>;
     static_assert(!is_array_v<_Up>, "Result of f(std::move(value())) should not be an Array");
@@ -1219,8 +1320,11 @@ public:
   }
 
   template <class _Func>
+#      if _LIBCPP_STD_VER >= 26
+    requires(is_object_v<_Tp>)
+#      endif
   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto transform(_Func&& __f) const&& {
-    using _Up = remove_cvref_t<invoke_result_t<_Func, const _Tp&&>>;
+    using _Up = remove_cv_t<invoke_result_t<_Func, const _Tp&&>>;
     static_assert(!is_array_v<_Up>, "Result of f(std::move(value())) should not be an Array");
     static_assert(!is_same_v<_Up, in_place_t>, "Result of f(std::move(value())) should not be std::in_place_t");
     static_assert(!is_same_v<_Up, nullopt_t>, "Result of f(std::move(value())) should not be std::nullopt_t");
@@ -1233,6 +1337,9 @@ public:
   template <invocable _Func>
   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr optional or_else(_Func&& __f) const&
     requires is_copy_constructible_v<_Tp>
+#      if _LIBCPP_STD_VER >= 26
+             && (is_object_v<_Tp>)
+#      endif
   {
     static_assert(is_same_v<remove_cvref_t<invoke_result_t<_Func>>, optional>,
                   "Result of f() should be the same type as this optional");
@@ -1244,6 +1351,9 @@ public:
   template <invocable _Func>
   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr optional or_else(_Func&& __f) &&
     requires is_move_constructible_v<_Tp>
+#      if _LIBCPP_STD_VER >= 26
+             && (is_object_v<_Tp>)
+#      endif
   {
     static_assert(is_same_v<remove_cvref_t<invoke_result_t<_Func>>, optional>,
                   "Result of f() should be the same type as this optional");
@@ -1254,6 +1364,78 @@ public:
 #    endif // _LIBCPP_STD_VER >= 23
 
   using __base::reset;
+
+// optional<T&> overloads
+#    if _LIBCPP_STD_VER >= 26
+
+  _LIBCPP_HIDE_FROM_ABI constexpr add_pointer_t<_Tp> operator->() const noexcept
+    requires(is_lvalue_reference_v<_Tp>)
+  {
+    _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(this->has_value(), "optional operator-> called on a disengaged value");
+    return std::addressof(this->__get());
+  }
+
+  [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr _Tp& operator*() const noexcept
+    requires(is_lvalue_reference_v<_Tp>)
+  {
+    _LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(this->has_value(), "optional operator* called on a disengaged value");
+    return this->__get();
+  }
+
+  [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr _Tp& value() const
+    requires(is_lvalue_reference_v<_Tp>)
+  {
+    if (!this->has_value())
+      std::__throw_bad_optional_access();
+    return this->__get();
+  }
+
+  template <class _Up = remove_cvref_t<_Tp>>
+    requires(is_lvalue_reference_v<_Tp> && is_object_v<__libcpp_remove_reference_t<_Tp>> &&
+             !is_array_v<__libcpp_remove_reference_t<_Tp>>)
+  [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr decay_t<_Tp> value_or(_Up&& __v) const {
+    static_assert(
+        is_constructible_v<remove_cvref_t<_Tp>, _Tp&>, "optional<T&>::value_or: remove_cv_t<T> must be constructible");
+    static_assert(
+        is_convertible_v<_Up, remove_cvref_t<_Tp>>, "optional<T&>::value_or: U must be convertible to remove_cv_t<T>");
+    return this->has_value() ? this->__get() : static_cast<remove_cvref_t<_Tp>>(std::forward<_Up>(__v));
+  }
+
+  template <class _Func>
+    requires(is_lvalue_reference_v<_Tp>)
+  [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto and_then(_Func&& __f) const {
+    using _Up = invoke_result_t<_Func, _Tp&>;
+    static_assert(__is_std_optional<remove_cvref_t<_Up>>::value,
+                  "Result of f(value()) must be a specialization of std::optional");
+    if (*this)
+      return std::invoke(std::forward<_Func>(__f), value());
+    return remove_cvref_t<_Up>();
+  }
+
+  template <class _Func>
+    requires(is_lvalue_reference_v<_Tp>)
+  [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr optional<remove_cv_t<invoke_result_t<_Func, _Tp&>>>
+  transform(_Func&& __f) const {
+    using _Up = remove_cvref_t<invoke_result_t<_Func, _Tp&>>;
+    static_assert(!is_array_v<_Up>, "Result of f(value()) should not be an Array");
+    static_assert(!is_same_v<_Up, in_place_t>, "Result of f(value()) should not be std::in_place_t");
+    static_assert(!is_same_v<_Up, nullopt_t>, "Result of f(value()) should not be std::nullopt_t");
+    static_assert(is_object_v<_Up>, "Result of f(value()) should be an object type");
+    if (*this)
+      return optional<_Up>(__optional_construct_from_invoke_tag{}, std::forward<_Func>(__f), value());
+    return optional<_Up>();
+  }
+
+  template <invocable _Func>
+    requires(is_lvalue_reference_v<_Tp>)
+  [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr optional or_else(_Func&& __f) const {
+    static_assert(is_same_v<remove_cvref_t<invoke_result_t<_Func>>, optional>,
+                  "Result of f() should be the same type as this optional");
+    if (*this)
+      return *this;
+    return std::forward<_Func>(__f)();
+  }
+#    endif
 };
 
 template <class _Tp>

diff  --git a/libcxx/test/libcxx/utilities/optional/optional.object/optional.object.observe/value_or.compile.pass.cpp b/libcxx/test/libcxx/utilities/optional/optional.object/optional.object.observe/value_or.compile.pass.cpp
index 25df0dd6c1936..1071184561dc1 100644
--- a/libcxx/test/libcxx/utilities/optional/optional.object/optional.object.observe/value_or.compile.pass.cpp
+++ b/libcxx/test/libcxx/utilities/optional/optional.object/optional.object.observe/value_or.compile.pass.cpp
@@ -22,7 +22,7 @@ concept has_value_or = requires(Opt opt, T&& t) {
 };
 
 static_assert(has_value_or<std::optional<int>, int>);
-static_assert(has_value_or<std::optional<int&>, int&>);
-static_assert(has_value_or<std::optional<const int&>, const int&>);
+static_assert(has_value_or<std::optional<int&>, int>);
+static_assert(has_value_or<std::optional<const int&>, int>);
 static_assert(!has_value_or<std::optional<int (&)[1]>&&, int (&)[1]>);
 static_assert(!has_value_or<std::optional<int (&)()>&&, int (&)()>);

diff  --git a/libcxx/test/std/utilities/optional/optional.monadic/and_then.pass.cpp b/libcxx/test/std/utilities/optional/optional.monadic/and_then.pass.cpp
index 810283a4bc80e..93bbd74cd8678 100644
--- a/libcxx/test/std/utilities/optional/optional.monadic/and_then.pass.cpp
+++ b/libcxx/test/std/utilities/optional/optional.monadic/and_then.pass.cpp
@@ -18,6 +18,7 @@
 #include <cassert>
 #include <concepts>
 #include <optional>
+#include <utility>
 
 #include "test_macros.h"
 
@@ -260,8 +261,9 @@ constexpr bool test() {
 
 #if TEST_STD_VER >= 26
 constexpr bool test_ref() {
-  // Test & overload
-  {
+  // Test "overloads", only the const (no ref-qualifier) and_then() should be called
+
+  { // &
     // Without & qualifier on F's operator()
     {
       int j = 42;
@@ -276,21 +278,21 @@ constexpr bool test_ref() {
     {
       int j = 42;
       std::optional<int&> i{j};
+      auto& io = i;
       RefQual l{};
       NORefQual nl{};
-      std::same_as<std::optional<int>> decltype(auto) r = i.and_then(l);
+      std::same_as<std::optional<int>> decltype(auto) r = io.and_then(l);
 
       assert(r == 1);
-      assert(i.and_then(nl) == std::nullopt);
+      assert(io.and_then(nl) == std::nullopt);
     }
   }
 
-  // Test const& overload
-  {
+  { // const&
     // Without & qualifier on F's operator()
     {
       int j = 42;
-      std::optional<const int&> i{j};
+      const std::optional<const int&> i{j};
       std::same_as<std::optional<int>> decltype(auto) r = i.and_then(CLVal{});
 
       assert(r == 1);
@@ -309,7 +311,8 @@ constexpr bool test_ref() {
       assert(i.and_then(nl) == std::nullopt);
     }
   }
-  // Test && overload
+
+  // &&
   {
     //With & qualifier on F's operator()
     {
@@ -318,11 +321,11 @@ constexpr bool test_ref() {
       std::same_as<std::optional<int>> decltype(auto) r = i.and_then(RVRefQual{});
 
       assert(r == 1);
-      assert(i.and_then(NORVRefQual{}) == std::nullopt);
+      assert(std::move(i).and_then(NORVRefQual{}) == std::nullopt);
     }
   }
 
-  // Test const&& overload
+  // const&&
   {
     //With & qualifier on F's operator()
     {
@@ -330,10 +333,10 @@ constexpr bool test_ref() {
       const std::optional<int&> i{j};
       const RVCRefQual l{};
       const NORVCRefQual nl{};
-      std::same_as<std::optional<int>> decltype(auto) r = i.and_then(std::move(l));
+      std::same_as<std::optional<int>> decltype(auto) r = std::move(i).and_then(std::move(l));
 
       assert(r == 1);
-      assert(i.and_then(std::move(nl)) == std::nullopt);
+      assert(std::move(i).and_then(std::move(nl)) == std::nullopt);
     }
   }
   return true;

diff  --git a/libcxx/test/std/utilities/optional/optional.monadic/or_else.pass.cpp b/libcxx/test/std/utilities/optional/optional.monadic/or_else.pass.cpp
index 0c330e30055a2..326013cd6557f 100644
--- a/libcxx/test/std/utilities/optional/optional.monadic/or_else.pass.cpp
+++ b/libcxx/test/std/utilities/optional/optional.monadic/or_else.pass.cpp
@@ -75,6 +75,13 @@ constexpr bool test() {
     });
     assert(opt == j);
   }
+
+  {
+    int i = 2;
+    const std::optional<int&> opt;
+    assert(opt.or_else([&] { return std::optional<int&>{i}; }) == i);
+  }
+
   {
     int i = 2;
     std::optional<int&> opt;
@@ -87,6 +94,16 @@ constexpr bool test() {
     });
     assert(opt == j);
   }
+
+  {
+    int i                         = 2;
+    const std::optional<int&> opt = i;
+    assert(std::move(opt).or_else([] {
+      assert(false);
+      return std::optional<int&>{};
+    }) == i);
+  }
+
 #endif
 
   return true;

diff  --git a/libcxx/test/std/utilities/optional/optional.monadic/transform.pass.cpp b/libcxx/test/std/utilities/optional/optional.monadic/transform.pass.cpp
index 36939f0b6b62e..b8536b790f749 100644
--- a/libcxx/test/std/utilities/optional/optional.monadic/transform.pass.cpp
+++ b/libcxx/test/std/utilities/optional/optional.monadic/transform.pass.cpp
@@ -204,6 +204,8 @@ constexpr bool test() {
 
 #if TEST_STD_VER >= 26
 constexpr bool test_ref() {
+  // Test that no matter the ref qualifier on the object .transform() is invoked on, only the added
+  // const (no ref-qualifier) overload is used
   {
     std::optional<int&> opt1;
     std::same_as<std::optional<int>> decltype(auto) opt1r = opt1.transform([](int i) { return i + 2; });
@@ -218,7 +220,16 @@ constexpr bool test_ref() {
 
     assert(*o2 == 44);
   }
-  // Test & overload
+
+  {
+    int i   = 42;
+    float k = 4.0f;
+    std::optional<int&> opt{i};
+    std::same_as<std::optional<float>> decltype(auto) o2 = opt.transform([&](int&) { return k; });
+    assert(*o2 == 4.0f);
+  }
+
+  // &
   {
     // Without & qualifier on F's operator()
     {
@@ -244,7 +255,7 @@ constexpr bool test_ref() {
     // Without & qualifier on F's operator()
     {
       int i = 42;
-      std::optional<const int&> opt{i};
+      const std::optional<const int&> opt{i};
       std::same_as<std::optional<int>> decltype(auto) o3 = std::as_const(opt).transform(CLVal{});
 
       assert(*o3 == 1);
@@ -266,8 +277,8 @@ constexpr bool test_ref() {
     // Without & qualifier on F's operator()
     {
       int i = 42;
-      std::optional<int> opt{i};
-      std::same_as<std::optional<int>> decltype(auto) o3 = std::move(opt).transform(RVal{});
+      std::optional<int&> opt{i};
+      std::same_as<std::optional<int>> decltype(auto) o3 = std::move(opt).transform(LVal{});
 
       assert(*o3 == 1);
     }
@@ -286,9 +297,9 @@ constexpr bool test_ref() {
     //With & qualifier on F's operator()
     {
       int i = 42;
-      std::optional<int&> opt{i};
+      const std::optional<int&> opt{i};
       const RVCRefQual rvc{};
-      std::same_as<std::optional<int>> decltype(auto) o3 = opt.transform(std::move(rvc));
+      std::same_as<std::optional<int>> decltype(auto) o3 = std::move(opt).transform(std::move(rvc));
       assert(*o3 == 1);
     }
   }

diff  --git a/libcxx/test/std/utilities/optional/optional.object/optional.object.assign/assign_value.pass.cpp b/libcxx/test/std/utilities/optional/optional.object/optional.object.assign/assign_value.pass.cpp
index ddb9ffc4bf80c..f1e2493954d38 100644
--- a/libcxx/test/std/utilities/optional/optional.object/optional.object.assign/assign_value.pass.cpp
+++ b/libcxx/test/std/utilities/optional/optional.object/optional.object.assign/assign_value.pass.cpp
@@ -18,6 +18,9 @@
 
 #include "test_macros.h"
 #include "archetypes.h"
+#if TEST_STD_VER >= 26
+#  include "copy_move_types.h"
+#endif
 
 using std::optional;
 
@@ -252,9 +255,9 @@ constexpr T pr38638(T v)
 
 #if TEST_STD_VER >= 26
 
-template <typename T, std::remove_reference_t<T> _Val>
-constexpr void test_with_ref() {
-  T t{_Val};
+template <typename T>
+constexpr bool test_with_ref(std::decay_t<T> val) {
+  T t{val};
   { // to empty
     optional<T&> opt;
     opt = t;
@@ -280,7 +283,7 @@ constexpr void test_with_ref() {
   }
   // test two objects, make sure that the optional only changes what it holds a reference to
   {
-    T t2{_Val};
+    T t2{val};
     optional<T&> opt{t};
     opt = t2;
 
@@ -299,6 +302,20 @@ constexpr void test_with_ref() {
     assert(std::addressof(*opt) == std::addressof(j));
     assert(*opt == 2);
   }
+
+  { // test that no copy is made when assigning
+    TracedCopyMove t1{};
+    TracedCopyMove t2{};
+
+    optional<TracedCopyMove&> o(t1);
+
+    o = t2;
+    assert(std::addressof(*o) == &t2);
+    assert(o->constCopy == 0);
+    assert(o->nonConstCopy == 0);
+  }
+
+  return true;
 }
 #endif
 
@@ -333,7 +350,10 @@ int main(int, char**)
     static_assert(pr38638(3) == 5, "");
 
 #if TEST_STD_VER >= 26
-    test_with_ref<int, 3>();
+    test_with_ref<int>(3);
+    test_with_ref<ConstexprTestTypes::Copyable>({});
+    static_assert(test_with_ref<int>(3));
+    static_assert(test_with_ref<ConstexprTestTypes::Copyable>({}));
 #endif
     return 0;
 }

diff  --git a/libcxx/test/std/utilities/optional/optional.object/optional.object.assign/const_optional_U.pass.cpp b/libcxx/test/std/utilities/optional/optional.object/optional.object.assign/const_optional_U.pass.cpp
index 4751f8e60994e..6b6dcbf428380 100644
--- a/libcxx/test/std/utilities/optional/optional.object/optional.object.assign/const_optional_U.pass.cpp
+++ b/libcxx/test/std/utilities/optional/optional.object/optional.object.assign/const_optional_U.pass.cpp
@@ -195,6 +195,34 @@ void test_ambiguous_assign() {
     }
 }
 
+#if TEST_STD_VER >= 26
+constexpr bool test_ref() {
+  {
+    int t{2};
+    const std::optional<int&> o1{t};
+    std::optional<int&> o2 = o1;
+
+    assert(&(*o2) == &t);
+    assert(o1.has_value());
+    assert(o2.has_value());
+    assert(*o2 == 2);
+  }
+
+  {
+    int t{2};
+
+    const std::optional<int&> o1{t};
+    std::optional<int> o2 = o1;
+
+    assert(&(*o2) != &t);
+    assert(o1.has_value());
+    assert(o2.has_value());
+    assert(*o2 == 2);
+  }
+
+  return true;
+}
+#endif
 
 int main(int, char**)
 {
@@ -251,5 +279,10 @@ int main(int, char**)
     }
 #endif
 
-  return 0;
+#if TEST_STD_VER >= 26
+    assert(test_ref());
+    static_assert(test_ref());
+#endif
+
+    return 0;
 }

diff  --git a/libcxx/test/std/utilities/optional/optional.object/optional.object.assign/copy.pass.cpp b/libcxx/test/std/utilities/optional/optional.object/optional.object.assign/copy.pass.cpp
index 9753fdb46b862..b4702baa49e1c 100644
--- a/libcxx/test/std/utilities/optional/optional.object/optional.object.assign/copy.pass.cpp
+++ b/libcxx/test/std/utilities/optional/optional.object/optional.object.assign/copy.pass.cpp
@@ -49,6 +49,55 @@ constexpr bool assign_value(optional<Tp>&& lhs) {
     return lhs.has_value() && rhs.has_value() && *lhs == *rhs;
 }
 
+#if TEST_STD_VER >= 26
+constexpr bool test_ref() {
+  struct TraceCopyAssign {
+    int copyAssign              = 0;
+    mutable int constCopyAssign = 0;
+
+    constexpr TraceCopyAssign() = default;
+    constexpr TraceCopyAssign(TraceCopyAssign& r) : copyAssign(r.copyAssign + 1), constCopyAssign(r.constCopyAssign) {}
+    constexpr TraceCopyAssign(const TraceCopyAssign& r)
+        : copyAssign(r.copyAssign), constCopyAssign(r.constCopyAssign + 1) {}
+    constexpr TraceCopyAssign& operator=(const TraceCopyAssign&) {
+      copyAssign++;
+      return *this;
+    }
+    constexpr const TraceCopyAssign& operator=(const TraceCopyAssign&) const {
+      constCopyAssign++;
+      return *this;
+    }
+  };
+  using T = TraceCopyAssign;
+  {
+    T t{};
+    std::optional<T&> o1{t};
+    std::optional<T&> o2 = o1;
+
+    assert(&(*o2) == &t);
+    assert(&(*o2) == &(*o1));
+    assert(t.constCopyAssign == 0);
+    assert(t.copyAssign == 0);
+    assert(o1.has_value());
+    assert(o2.has_value());
+  }
+  {
+    T t{};
+    std::optional<T&> o1{t};
+    std::optional<T> o2 = o1;
+
+    assert(&(*o2) != &t);
+    assert(&(*o2) != &(*o1));
+    assert(o2->constCopyAssign == 0);
+    assert(o2->copyAssign == 1);
+    assert(o1.has_value());
+    assert(o2.has_value());
+  }
+
+  return true;
+}
+#endif
+
 int main(int, char**)
 {
     {
@@ -100,5 +149,10 @@ int main(int, char**)
     }
 #endif
 
-  return 0;
+#if TEST_STD_VER >= 26
+    assert(test_ref());
+    static_assert(test_ref());
+#endif
+
+    return 0;
 }

diff  --git a/libcxx/test/std/utilities/optional/optional.object/optional.object.assign/emplace.pass.cpp b/libcxx/test/std/utilities/optional/optional.object/optional.object.assign/emplace.pass.cpp
index 629e315add4d9..3321d55ec5869 100644
--- a/libcxx/test/std/utilities/optional/optional.object/optional.object.assign/emplace.pass.cpp
+++ b/libcxx/test/std/utilities/optional/optional.object/optional.object.assign/emplace.pass.cpp
@@ -231,6 +231,7 @@ constexpr bool test_ref() {
     auto& v = opt.emplace(t);
     static_assert(std::is_same_v<T&, decltype(v)>);
     assert(static_cast<bool>(opt) == true);
+    ASSERT_NOEXCEPT(opt.emplace(t));
     assert(*opt == t);
     assert(&v == &*opt);
     assert(&t == &*opt);

diff  --git a/libcxx/test/std/utilities/optional/optional.object/optional.object.assign/emplace.verify.cpp b/libcxx/test/std/utilities/optional/optional.object/optional.object.assign/emplace.verify.cpp
new file mode 100644
index 0000000000000..a0bfa078f189c
--- /dev/null
+++ b/libcxx/test/std/utilities/optional/optional.object/optional.object.assign/emplace.verify.cpp
@@ -0,0 +1,26 @@
+//===----------------------------------------------------------------------===//
+//
+// 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++26
+// <optional>
+
+// template <class U> T& optional<T&>::emplace(U&& arg);
+// Ensure that emplace isn't found if reference_constructs_From_temporary_v == true or is_constructible_v<_Tp&, U> == false
+#include <optional>
+#include <type_traits>
+
+struct X {};
+void test() {
+  int i = 1;
+  std::optional<X&> f{};
+  static_assert(!std::is_constructible_v<X&, int>); // is_constructible_v<_Tp&, U> == false
+  f.emplace(i); // expected-error {{no matching member function for call to 'emplace'}}
+
+  std::optional<const int&> t{}; // reference_constructs_from_temporary_v == false
+  t.emplace(1);                  // expected-error {{no matching member function for call to 'emplace'}}
+}

diff  --git a/libcxx/test/std/utilities/optional/optional.object/optional.object.assign/move.pass.cpp b/libcxx/test/std/utilities/optional/optional.object/optional.object.assign/move.pass.cpp
index 85971e38f7b70..c447557cfa9d4 100644
--- a/libcxx/test/std/utilities/optional/optional.object/optional.object.assign/move.pass.cpp
+++ b/libcxx/test/std/utilities/optional/optional.object/optional.object.assign/move.pass.cpp
@@ -20,6 +20,9 @@
 
 #include "test_macros.h"
 #include "archetypes.h"
+#if TEST_STD_VER >= 26
+#  include "copy_move_types.h"
+#endif
 
 using std::optional;
 
@@ -66,6 +69,23 @@ constexpr bool assign_value(optional<Tp>&& lhs) {
     return lhs.has_value() && rhs.has_value() && *lhs == Tp{101};
 }
 
+#if TEST_STD_VER >= 26
+constexpr bool test_ref() {
+  using T = TracedAssignment;
+  {
+    T t{};
+    std::optional<T&> o1{t};
+    std::optional<T&> o2 = std::move(o1);
+
+    assert(&(*o2) == &t);
+    assert(o1.has_value());
+    assert(o2.has_value());
+    assert(t.moveAssign == 0);
+  }
+  return true;
+}
+#endif
+
 int main(int, char**)
 {
     {

diff  --git a/libcxx/test/std/utilities/optional/optional.object/optional.object.assign/nullopt_t.pass.cpp b/libcxx/test/std/utilities/optional/optional.object/optional.object.assign/nullopt_t.pass.cpp
index 9d0843b7338df..e85c0c435aa37 100644
--- a/libcxx/test/std/utilities/optional/optional.object/optional.object.assign/nullopt_t.pass.cpp
+++ b/libcxx/test/std/utilities/optional/optional.object/optional.object.assign/nullopt_t.pass.cpp
@@ -61,6 +61,17 @@ TEST_CONSTEXPR_CXX20 bool test()
         assert(state == State::destroyed);
         assert(static_cast<bool>(opt) == false);
     }
+
+#if TEST_STD_VER >= 26
+    {
+      int i = 0;
+      optional<int&> o{i};
+      ASSERT_NOEXCEPT(o = std::nullopt);
+      o = std::nullopt;
+      assert(!o.has_value());
+      assert(static_cast<bool>(o) == false);
+    }
+#endif
     return true;
 }
 

diff  --git a/libcxx/test/std/utilities/optional/optional.object/optional.object.assign/optional_U.pass.cpp b/libcxx/test/std/utilities/optional/optional.object/optional.object.assign/optional_U.pass.cpp
index cc1b17157f2b4..d23858e9974d5 100644
--- a/libcxx/test/std/utilities/optional/optional.object/optional.object.assign/optional_U.pass.cpp
+++ b/libcxx/test/std/utilities/optional/optional.object/optional.object.assign/optional_U.pass.cpp
@@ -293,7 +293,18 @@ TEST_CONSTEXPR_CXX20 bool test()
       assert(state[0] == state_t::inactive);
       assert(state[1] == state_t::copy_assigned);
     }
+#if TEST_STD_VER >= 26
+    {
+      state_t state{state_t::constructed};
+      StateTracker t{state};
+      std::optional<StateTracker&> o1{t};
+      std::optional<StateTracker> o2 = std::move(o1);
+      (void)*o2;
+      assert(state != state_t::move_assigned);
+      assert(state == state_t::constructed);
+    }
 
+#endif
     return true;
 }
 
@@ -301,7 +312,8 @@ TEST_CONSTEXPR_CXX20 bool test()
 int main(int, char**)
 {
 #if TEST_STD_VER > 17
-    static_assert(test());
+  assert(test());
+  static_assert(test());
 #endif
     test_with_test_type();
     test_ambiguous_assign();

diff  --git a/libcxx/test/std/utilities/optional/optional.object/optional.object.ctor/U.pass.cpp b/libcxx/test/std/utilities/optional/optional.object/optional.object.ctor/U.pass.cpp
index 1e951ebdf1d74..1cdb429f485e5 100644
--- a/libcxx/test/std/utilities/optional/optional.object/optional.object.ctor/U.pass.cpp
+++ b/libcxx/test/std/utilities/optional/optional.object/optional.object.ctor/U.pass.cpp
@@ -21,6 +21,8 @@
 #include "archetypes.h"
 #include "test_convertible.h"
 
+#include "../optional_helper_types.h"
+
 using std::optional;
 
 struct ImplicitThrow {
@@ -149,9 +151,72 @@ void test_explicit() {
 #endif
 }
 
+#if TEST_STD_VER >= 26
+constexpr bool test_ref() {
+  {
+    int i = 0;
+    std::optional<int&> o(i);
+    ASSERT_NOEXCEPT(std::optional<int&>(i));
+    assert(o.has_value());
+    assert(&(*o) == &i);
+    assert(*o == 0);
+    assert(o.value() == 0);
+  }
+
+  {
+    ReferenceConversion<int> t{1, 2};
+    ASSERT_NOEXCEPT(std::optional<int&>(t));
+    std::optional<int&> o(t);
+    assert(o.has_value());
+    assert(&(*o) == &t.lvalue);
+    assert(*o == 1);
+  }
+
+  {
+    ReferenceConversion<int> t{1, 2};
+    ASSERT_NOEXCEPT(std::optional<int&>(std::move(t)));
+    std::optional<int&> o(std::move(t));
+    assert(o.has_value());
+    assert(&(*o) == &t.rvalue);
+    assert(*o == 2);
+  }
+
+#  ifndef TEST_HAS_NO_EXCEPTIONS
+  {
+    ReferenceConversionThrows<int> t{1, 2, false};
+    ASSERT_NOT_NOEXCEPT(std::optional<int&>(t));
+    try {
+      std::optional<int&> o(t);
+      assert(o.has_value());
+      assert(&(*o) == &t.lvalue);
+      assert(*o == 1);
+    } catch (int) {
+      assert(false);
+    }
+  }
+  {
+    ReferenceConversionThrows<int> t{1, 2, false};
+    ASSERT_NOT_NOEXCEPT(std::optional<int&>(std::move(t)));
+    try {
+      std::optional<int&> o(std::move(t));
+      assert(o.has_value());
+      assert(&(*o) == &t.rvalue);
+      assert(*o == 2);
+    } catch (int) {
+      assert(false);
+    }
+  }
+#  endif
+  return true;
+}
+#endif
+
 int main(int, char**) {
   test_implicit();
   test_explicit();
-
+#if TEST_STD_VER >= 26
+  assert(test_ref());
+  static_assert(test_ref());
+#endif
   return 0;
 }

diff  --git a/libcxx/test/std/utilities/optional/optional.object/optional.object.ctor/const_optional_U.pass.cpp b/libcxx/test/std/utilities/optional/optional.object/optional.object.ctor/const_optional_U.pass.cpp
index 70fd76ec6ed0b..597110bcb54fe 100644
--- a/libcxx/test/std/utilities/optional/optional.object/optional.object.ctor/const_optional_U.pass.cpp
+++ b/libcxx/test/std/utilities/optional/optional.object/optional.object.ctor/const_optional_U.pass.cpp
@@ -11,11 +11,13 @@
 
 // template <class U>
 //   optional(const optional<U>& rhs);
+//optional<T&>: optional(const optional<U>&& rhs);
 
 #include <cassert>
 #include <optional>
 #include <type_traits>
 
+#include "../optional_helper_types.h"
 #include "test_macros.h"
 
 using std::optional;
@@ -86,6 +88,73 @@ constexpr bool test_all() {
   return true;
 }
 
+#if TEST_STD_VER >= 26
+constexpr bool test_ref() {
+  // optional(const optional<U>&)
+  {
+    int i = 1;
+    const std::optional<int&> o1{i};
+    const std::optional<int&> o2{o1};
+
+    ASSERT_NOEXCEPT(std::optional<int&>(o2));
+    assert(o2.has_value());
+    assert(&(*o1) == &(*o2));
+    assert(*o1 == i);
+    assert(*o2 == i);
+  }
+
+  {
+    const std::optional<int&> o1;
+    const std::optional<int&> o2{o1};
+    ASSERT_NOEXCEPT(std::optional<int&>(o2));
+    assert(!o2.has_value());
+  }
+
+  {
+    ReferenceConversion<int> t{1, 2};
+    const std::optional<ReferenceConversion<int>&> o1(t);
+    const std::optional<int&> o2(o1);
+    ASSERT_NOEXCEPT(std::optional<int&>(o1));
+    assert(o2.has_value());
+    assert(&(*o2) == &t.lvalue);
+    assert(*o2 == 1);
+  }
+
+  // optional(const optional<U>&&)
+  {
+    int i = 1;
+    const std::optional<int&> o1{i};
+    const std::optional<int&> o2{std::move(o1)};
+
+    // trivial move constructor should just copy the reference
+    ASSERT_NOEXCEPT(std::optional<int&>(std::move(o2)));
+    assert(o2.has_value());
+    assert(&(*o1) == &(*o2));
+    assert(*o1 == i);
+    assert(*o2 == i);
+  }
+
+  {
+    const std::optional<int&> o1;
+    const std::optional<int&> o2{std::move(o1)};
+    ASSERT_NOEXCEPT(std::optional<int&>(o2));
+    assert(!o2.has_value());
+  }
+
+  {
+    ReferenceConversion<int> t{1, 2};
+    const std::optional<ReferenceConversion<int>&> o1(t);
+    const std::optional<int&> o2(std::move(o1));
+    ASSERT_NOEXCEPT(std::optional<int&>(o1));
+    assert(o2.has_value());
+    assert(&(*o2) == &t.lvalue);
+    assert(*o2 == 1);
+  }
+
+  return true;
+}
+#endif
+
 int main(int, char**) {
   test_all<int, short>();
   test_all<X, int>();
@@ -109,6 +178,9 @@ int main(int, char**) {
   }
 
   static_assert(!(std::is_constructible<optional<X>, const optional<Y>&>::value), "");
-
+#if TEST_STD_VER >= 26
+  assert(test_ref());
+  static_assert(test_ref());
+#endif
   return 0;
 }

diff  --git a/libcxx/test/std/utilities/optional/optional.object/optional.object.ctor/copy.pass.cpp b/libcxx/test/std/utilities/optional/optional.object/optional.object.ctor/copy.pass.cpp
index f61a22c23a04d..fd7332f3b422b 100644
--- a/libcxx/test/std/utilities/optional/optional.object/optional.object.ctor/copy.pass.cpp
+++ b/libcxx/test/std/utilities/optional/optional.object/optional.object.ctor/copy.pass.cpp
@@ -69,8 +69,8 @@ void test_ref(InitArgs&&... args) {
     assert(&(*lhs) == &(*rhs));
 }
 
+#if TEST_STD_VER >= 26
 void test_reference_extension() {
-#if defined(_LIBCPP_VERSION) && 0 // FIXME these extensions are currently disabled.
   using T = TestTypes::TestType;
   T::reset();
   {
@@ -99,12 +99,15 @@ void test_reference_extension() {
   }
   assert(T::alive == 0);
   assert(T::destroyed == 1);
+
+#  if 0 // optional<T&&> is not permitted.
   {
     static_assert(!std::is_copy_constructible<std::optional<T&&>>::value, "");
     static_assert(!std::is_copy_constructible<std::optional<T const&&>>::value, "");
   }
-#endif
+#  endif
 }
+#endif
 
 int main(int, char**) {
   test<int>();
@@ -153,9 +156,11 @@ int main(int, char**) {
   {
     test_throwing_ctor();
   }
+#if TEST_STD_VER >= 26
   {
     test_reference_extension();
   }
+#endif
   {
     constexpr std::optional<int> o1{4};
     constexpr std::optional<int> o2 = o1;

diff  --git a/libcxx/test/std/utilities/optional/optional.object/optional.object.ctor/in_place_t.pass.cpp b/libcxx/test/std/utilities/optional/optional.object/optional.object.ctor/in_place_t.pass.cpp
index c8bdfc78225fa..c3b498e56a5a1 100644
--- a/libcxx/test/std/utilities/optional/optional.object/optional.object.ctor/in_place_t.pass.cpp
+++ b/libcxx/test/std/utilities/optional/optional.object/optional.object.ctor/in_place_t.pass.cpp
@@ -78,6 +78,23 @@ constexpr bool test_ref_initializer_list() {
 
   return true;
 }
+
+constexpr bool test_ref() {
+  { // optional(in_place_t, _Arg&&)
+    Y y{1, 2};
+    optional<Y&> xo(in_place, y);
+
+    Y x2{1, 2};
+
+    assert(*xo == x2);
+    assert(&(*xo) == &y);
+  }
+
+  assert(test_ref_initializer_list());
+  static_assert(test_ref_initializer_list());
+
+  return true;
+}
 #endif
 
 int main(int, char**) {
@@ -148,8 +165,8 @@ int main(int, char**) {
 #endif
 
 #if TEST_STD_VER >= 26
-  test_ref_initializer_list();
-  static_assert(test_ref_initializer_list());
+  test_ref();
+  static_assert(test_ref());
 #endif
 
   return 0;

diff  --git a/libcxx/test/std/utilities/optional/optional.object/optional.object.ctor/move.pass.cpp b/libcxx/test/std/utilities/optional/optional.object/optional.object.ctor/move.pass.cpp
index 583debcaac650..bb36283a5e3ea 100644
--- a/libcxx/test/std/utilities/optional/optional.object/optional.object.ctor/move.pass.cpp
+++ b/libcxx/test/std/utilities/optional/optional.object/optional.object.ctor/move.pass.cpp
@@ -78,26 +78,34 @@ void test_reference_extension() {
   T::reset();
   {
     T t;
-    T::reset_constructors();
-    test_ref<T&>();
-    test_ref<T&>(t);
+    {
+      T::reset_constructors();
+      test_ref<T&>();
+      test_ref<T&>(t);
+      assert(T::alive == 1);
+      assert(T::constructed == 0);
+      assert(T::assigned == 0);
+      assert(T::destroyed == 0);
+    } // destroying the optional<T&> doesn't destroy the underlying T
     assert(T::alive == 1);
-    assert(T::constructed == 0);
-    assert(T::assigned == 0);
     assert(T::destroyed == 0);
   }
   assert(T::destroyed == 1);
   assert(T::alive == 0);
   {
     T t;
-    const T& ct = t;
-    T::reset_constructors();
-    test_ref<T const&>();
-    test_ref<T const&>(t);
-    test_ref<T const&>(ct);
+    {
+      const T& ct = t;
+      T::reset_constructors();
+      test_ref<T const&>();
+      test_ref<T const&>(t);
+      test_ref<T const&>(ct);
+      assert(T::alive == 1);
+      assert(T::constructed == 0);
+      assert(T::assigned == 0);
+      assert(T::destroyed == 0);
+    }
     assert(T::alive == 1);
-    assert(T::constructed == 0);
-    assert(T::assigned == 0);
     assert(T::destroyed == 0);
   }
   assert(T::alive == 0);

diff  --git a/libcxx/test/std/utilities/optional/optional.object/optional.object.ctor/optional_U.pass.cpp b/libcxx/test/std/utilities/optional/optional.object/optional.object.ctor/optional_U.pass.cpp
index 709b106c800a6..39a80efa475f7 100644
--- a/libcxx/test/std/utilities/optional/optional.object/optional.object.ctor/optional_U.pass.cpp
+++ b/libcxx/test/std/utilities/optional/optional.object/optional.object.ctor/optional_U.pass.cpp
@@ -12,6 +12,8 @@
 // template <class U>
 //   optional(optional<U>&& rhs);
 
+// optional<T&>: optional(optional<U>& rhs)
+
 #include <cassert>
 #include <memory>
 #include <optional>
@@ -19,6 +21,11 @@
 #include <utility>
 
 #include "test_macros.h"
+#if TEST_STD_VER >= 26
+#  include "copy_move_types.h"
+#endif
+
+#include "../optional_helper_types.h"
 
 using std::optional;
 
@@ -68,6 +75,79 @@ TEST_CONSTEXPR_CXX20 bool test_all() {
   return true;
 }
 
+#if TEST_STD_VER >= 26
+constexpr bool test_ref() {
+  // optional(optional<U>&)
+  {
+    int i = 1;
+    std::optional<int&> o1{i};
+    std::optional<int&> o2{o1};
+
+    ASSERT_NOEXCEPT(std::optional<int&>(o2));
+    assert(o2.has_value());
+    assert(&(*o1) == &(*o2));
+    assert(*o1 == i);
+    assert(*o2 == i);
+  }
+
+  {
+    std::optional<int&> o1;
+    std::optional<int&> o2{o1};
+    ASSERT_NOEXCEPT(std::optional<int&>(o2));
+    assert(!o2.has_value());
+  }
+
+  {
+    ReferenceConversion<int> t{1, 2};
+    std::optional<ReferenceConversion<int>&> o1(t);
+    std::optional<int&> o2(o1);
+    ASSERT_NOEXCEPT(std::optional<int&>(o1));
+    assert(o2.has_value());
+    assert(&(*o2) == &t.lvalue);
+    assert(*o2 == 1);
+  }
+  // optional(optional<U>&&)
+  {
+    int i = 1;
+    std::optional<int&> o1{i};
+    std::optional<int&> o2{std::move(o1)};
+
+    // trivial move constructor should just copy the reference
+    ASSERT_NOEXCEPT(std::optional<int&>(o2));
+    assert(o2.has_value());
+    assert(&(*o1) == &(*o2));
+    assert(*o1 == i);
+    assert(*o2 == i);
+  }
+
+  {
+    std::optional<int&> o1;
+    std::optional<int&> o2{std::move(o1)};
+    ASSERT_NOEXCEPT(std::optional<int&>(o2));
+    assert(!o2.has_value());
+  }
+  {
+    TracedCopyMove t{};
+    std::optional<TracedCopyMove&> o1{t};
+    std::optional<TracedCopyMove> o2{std::move(o1)};
+    assert(t.constMove == 0);
+    assert(t.nonConstMove == 0);
+  }
+
+  {
+    ReferenceConversion<int> t{1, 2};
+    std::optional<ReferenceConversion<int>&> o1(t);
+    std::optional<int&> o2(std::move(o1));
+    ASSERT_NOEXCEPT(std::optional<int&>(o1));
+    assert(o2.has_value());
+    assert(&(*o2) == &t.lvalue);
+    assert(*o2 == 1);
+  }
+
+  return true;
+}
+#endif
+
 int main(int, char**) {
   test_all<short, int>();
   test_all<int, X>();
@@ -86,5 +166,9 @@ int main(int, char**) {
 
   static_assert(!(std::is_constructible<optional<X>, optional<Z>>::value), "");
 
+#if TEST_STD_VER >= 26
+  assert(test_ref());
+  static_assert(test_ref());
+#endif
   return 0;
 }

diff  --git a/libcxx/test/std/utilities/optional/optional.object/optional.object.ctor/ref_constructs_from_temporary.verify.cpp b/libcxx/test/std/utilities/optional/optional.object/optional.object.ctor/ref_constructs_from_temporary.verify.cpp
index 01b241ffbe79b..53ac77a2e5620 100644
--- a/libcxx/test/std/utilities/optional/optional.object/optional.object.ctor/ref_constructs_from_temporary.verify.cpp
+++ b/libcxx/test/std/utilities/optional/optional.object/optional.object.ctor/ref_constructs_from_temporary.verify.cpp
@@ -8,7 +8,13 @@
 
 // REQUIRES: std-at-least-c++26
 
-// optional
+// <optional>
+
+// optional(U&& u) noexcept(is_nothrow_constructible_v<T&, U>);
+// optional(optional<U>& rhs) noexcept(is_nothrow_constructible_v<T&, U&>);
+// optional(const optional<U>& rhs) noexcept(is_nothrow_constructible_v<T&, const U&>);
+// optional(optional<U>&& rhs) noexcept(is_nothrow_constructible_v<T&, U>);
+// optional(const optional<U>&& rhs) noexcept(is_nothrow_constructible_v<T&, const U>);
 
 #include <optional>
 #include <utility>
@@ -19,17 +25,20 @@ struct X {
   X(int j) : i(j) {}
 };
 
-int main(int, char**) {
-  const std::optional<int> _co(1);
-  std::optional<int> _o(1);
-
-  // expected-error-re@*:* 8 {{call to deleted constructor of 'std::optional<{{.*}}>'}}
-  std::optional<const int&> o1{1};                     // optional(U&&)
-  std::optional<const int&> o2{std::optional<int>(1)}; // optional(optional<U>&&)
-  std::optional<const int&> o3{_co};                   // optional(const optional<U>&)
-  std::optional<const int&> o4{_o};                    // optional(optional<U>&)
-  std::optional<const X&> o5{1};                       // optional(U&&)
-  std::optional<const X&> o6{std::optional<int>(1)};   // optional(optional<U>&&)
-  std::optional<const X&> o7{_co};                     // optional(const optional<U>&)
-  std::optional<const X&> o8{_o};                      // optional(optional<U>&)
+void test() {
+  const std::optional<int> co(1);
+  std::optional<int> o0(1);
+
+  // expected-error-re@*:* 10 {{call to deleted constructor of 'std::optional<{{.*}}>'}}
+  std::optional<const int&> o1{1};             // optional(U&&)
+  std::optional<const int&> o2{o0};            // optional(optional<U>&)
+  std::optional<const int&> o3{co};            // optional(const optional<U>&)
+  std::optional<const int&> o4{std::move(o0)}; // optional(optional<U>&&&)
+  std::optional<const int&> o5{std::move(co)}; // optional(optional<U>&&&)
+
+  std::optional<const X&> o6{1};              // optional(U&&)
+  std::optional<const X&> o7{o0};             // optional(optional<U>&)
+  std::optional<const X&> o8(co);             // optional(const optional<U>&)
+  std::optional<const X&> o9{std::move(o0)};  // optional(optional<U>&&)
+  std::optional<const X&> o10{std::move(co)}; // optional(const optional<U>&&)
 }

diff  --git a/libcxx/test/std/utilities/optional/optional.object/optional.object.mod/reset.pass.cpp b/libcxx/test/std/utilities/optional/optional.object/optional.object.mod/reset.pass.cpp
index e23e481f6a05d..a7ae22861d32e 100644
--- a/libcxx/test/std/utilities/optional/optional.object/optional.object.mod/reset.pass.cpp
+++ b/libcxx/test/std/utilities/optional/optional.object/optional.object.mod/reset.pass.cpp
@@ -75,6 +75,7 @@ int main(int, char**)
       optional<X&> opt(x);
       X::dtor_called = false;
       opt.reset();
+      ASSERT_NOEXCEPT(opt.reset());
       assert(X::dtor_called == false);
       assert(static_cast<bool>(opt) == false);
     }

diff  --git a/libcxx/test/std/utilities/optional/optional.object/optional.object.observe/bool.pass.cpp b/libcxx/test/std/utilities/optional/optional.object/optional.object.observe/bool.pass.cpp
index 684f18ff3df20..ccc6dea8a111a 100644
--- a/libcxx/test/std/utilities/optional/optional.object/optional.object.observe/bool.pass.cpp
+++ b/libcxx/test/std/utilities/optional/optional.object/optional.object.observe/bool.pass.cpp
@@ -10,13 +10,36 @@
 // <optional>
 
 // constexpr explicit optional<T>::operator bool() const noexcept;
+// constexpr explicit optional<T&>::operator bool() const noexcept;
 
+#include <cassert>
 #include <optional>
 #include <type_traits>
-#include <cassert>
 
 #include "test_macros.h"
 
+#if TEST_STD_VER >= 26
+
+constexpr bool test_ref() {
+  {
+    std::optional<int&> opt;
+    ASSERT_NOEXCEPT(bool(opt));
+    assert(!opt);
+    static_assert(!std::is_convertible<std::optional<int&>, bool>::value, "");
+  }
+  {
+    int i = 1;
+    std::optional<int&> opt(i);
+    ASSERT_NOEXCEPT(bool(opt));
+    assert(opt);
+    static_assert(!std::is_convertible<std::optional<int&>, bool>::value, "");
+  }
+
+  return true;
+}
+
+#endif
+
 int main(int, char**)
 {
     using std::optional;
@@ -34,5 +57,12 @@ int main(int, char**)
         static_assert(opt, "");
     }
 
-  return 0;
+#if TEST_STD_VER >= 26
+    {
+      assert(test_ref());
+      static_assert(test_ref());
+    }
+#endif
+
+    return 0;
 }

diff  --git a/libcxx/test/std/utilities/optional/optional.object/optional.object.observe/dereference.pass.cpp b/libcxx/test/std/utilities/optional/optional.object/optional.object.observe/dereference.pass.cpp
index 6c1bf8aa15a8d..72cf0446c7eb9 100644
--- a/libcxx/test/std/utilities/optional/optional.object/optional.object.observe/dereference.pass.cpp
+++ b/libcxx/test/std/utilities/optional/optional.object/optional.object.observe/dereference.pass.cpp
@@ -11,11 +11,14 @@
 
 // constexpr T& optional<T>::operator*() &;
 
-#include <optional>
-#include <type_traits>
 #include <cassert>
+#include <memory>
+#include <optional>
 
 #include "test_macros.h"
+#if TEST_STD_VER >= 26
+#  include "copy_move_types.h"
+#endif
 
 using std::optional;
 
@@ -39,6 +42,38 @@ test()
     return (*opt).test();
 }
 
+#if TEST_STD_VER >= 26
+constexpr bool test_ref() {
+  {
+    TracedCopyMove x{};
+    std::optional<TracedCopyMove&> opt(x);
+    static_assert(noexcept(*opt));
+    ASSERT_SAME_TYPE(decltype(*opt), TracedCopyMove&);
+
+    assert(std::addressof(*opt) == std::addressof(x));
+    assert(x.constMove == 0);
+    assert(x.nonConstMove == 0);
+    assert(x.constCopy == 0);
+    assert(x.nonConstCopy == 0);
+  }
+
+  {
+    TracedCopyMove x{};
+    std::optional<const TracedCopyMove&> opt(x);
+    static_assert(noexcept(*opt));
+    ASSERT_SAME_TYPE(decltype(*opt), const TracedCopyMove&);
+
+    assert(std::addressof(*opt) == std::addressof(x));
+    assert(x.constMove == 0);
+    assert(x.nonConstMove == 0);
+    assert(x.constCopy == 0);
+    assert(x.nonConstCopy == 0);
+  }
+
+  return true;
+}
+#endif
+
 int main(int, char**)
 {
     {

diff  --git a/libcxx/test/std/utilities/optional/optional.object/optional.object.observe/dereference_const.pass.cpp b/libcxx/test/std/utilities/optional/optional.object/optional.object.observe/dereference_const.pass.cpp
index c15d4e4af74cc..aefe8d37a142a 100644
--- a/libcxx/test/std/utilities/optional/optional.object/optional.object.observe/dereference_const.pass.cpp
+++ b/libcxx/test/std/utilities/optional/optional.object/optional.object.observe/dereference_const.pass.cpp
@@ -11,11 +11,14 @@
 
 // constexpr const T& optional<T>::operator*() const &;
 
-#include <optional>
-#include <type_traits>
 #include <cassert>
+#include <memory>
+#include <optional>
 
 #include "test_macros.h"
+#if TEST_STD_VER >= 26
+#  include "copy_move_types.h"
+#endif
 
 using std::optional;
 
@@ -32,6 +35,39 @@ struct Y
     int test() const {return 2;}
 };
 
+#if TEST_STD_VER >= 26
+constexpr bool test_ref() {
+  using T = TracedCopyMove;
+  {
+    T x{};
+    const std::optional<T&> opt(x);
+    ASSERT_NOEXCEPT(*opt);
+    ASSERT_SAME_TYPE(decltype(*opt), TracedCopyMove&);
+
+    assert(std::addressof(*opt) == std::addressof(x));
+    assert((*opt).constMove == 0);
+    assert((*opt).nonConstMove == 0);
+    assert((*opt).constCopy == 0);
+    assert((*opt).nonConstCopy == 0);
+  }
+
+  {
+    T x{};
+    const std::optional<const T&> opt(x);
+    ASSERT_NOEXCEPT(*opt);
+    ASSERT_SAME_TYPE(decltype(*opt), const TracedCopyMove&);
+
+    assert(std::addressof(*opt) == std::addressof(x));
+    assert((*opt).constMove == 0);
+    assert((*opt).nonConstMove == 0);
+    assert((*opt).constCopy == 0);
+    assert((*opt).nonConstCopy == 0);
+  }
+
+  return true;
+}
+#endif
+
 int main(int, char**)
 {
     {
@@ -43,29 +79,15 @@ int main(int, char**)
         constexpr optional<X> opt(X{});
         static_assert((*opt).test() == 3, "");
     }
-#if TEST_STD_VER >= 26
-    {
-      X x{};
-      const optional<X&> opt{x};
-      ASSERT_SAME_TYPE(decltype(*opt), X&);
-      ASSERT_NOEXCEPT(*opt);
-    }
     {
-      X x{};
-      const optional<const X&> opt{x};
-      ASSERT_SAME_TYPE(decltype(*opt), const X&);
-      ASSERT_NOEXCEPT(*opt);
+      constexpr optional<Y> opt(Y{});
+      assert((*opt).test() == 2);
     }
+#if TEST_STD_VER >= 26
     {
-      static constexpr X x{};
-      constexpr optional<const X&> opt(x);
-      static_assert((*opt).test() == 3);
+      assert(test_ref());
+      static_assert(test_ref());
     }
 #endif
-    {
-        constexpr optional<Y> opt(Y{});
-        assert((*opt).test() == 2);
-    }
-
     return 0;
 }

diff  --git a/libcxx/test/std/utilities/optional/optional.object/optional.object.observe/dereference_const_rvalue.pass.cpp b/libcxx/test/std/utilities/optional/optional.object/optional.object.observe/dereference_const_rvalue.pass.cpp
index 646857fdc0465..cbff9cf3b1d6b 100644
--- a/libcxx/test/std/utilities/optional/optional.object/optional.object.observe/dereference_const_rvalue.pass.cpp
+++ b/libcxx/test/std/utilities/optional/optional.object/optional.object.observe/dereference_const_rvalue.pass.cpp
@@ -11,11 +11,15 @@
 
 // constexpr T&& optional<T>::operator*() const &&;
 
-#include <optional>
-#include <type_traits>
 #include <cassert>
+#include <memory>
+#include <optional>
+#include <utility>
 
 #include "test_macros.h"
+#if TEST_STD_VER >= 26
+#  include "copy_move_types.h"
+#endif
 
 using std::optional;
 
@@ -32,6 +36,38 @@ struct Y
     int test() const && {return 2;}
 };
 
+#if TEST_STD_VER >= 26
+constexpr bool test_ref() {
+  { // const&&
+    TracedCopyMove x{};
+    const std::optional<TracedCopyMove&> opt(x);
+    ASSERT_NOEXCEPT(*std::move(opt));
+    ASSERT_SAME_TYPE(decltype(*std::move(opt)), TracedCopyMove&);
+
+    assert(std::addressof(*(std::move(opt))) == std::addressof(x));
+    assert((*std::move(opt)).constMove == 0);
+    assert((*std::move(opt)).nonConstMove == 0);
+    assert((*std::move(opt)).constCopy == 0);
+    assert((*std::move(opt)).nonConstCopy == 0);
+  }
+
+  {
+    TracedCopyMove x{};
+    const std::optional<const TracedCopyMove&> opt(x);
+    ASSERT_NOEXCEPT(*std::move(opt));
+    ASSERT_SAME_TYPE(decltype(*std::move(opt)), const TracedCopyMove&);
+
+    assert(std::addressof(*(std::move(opt))) == std::addressof(x));
+    assert((*std::move(opt)).constMove == 0);
+    assert((*std::move(opt)).nonConstMove == 0);
+    assert((*std::move(opt)).constCopy == 0);
+    assert((*std::move(opt)).nonConstCopy == 0);
+  }
+
+  return true;
+}
+#endif
+
 int main(int, char**)
 {
     {
@@ -48,5 +84,10 @@ int main(int, char**)
         assert((*std::move(opt)).test() == 2);
     }
 
+#if TEST_STD_VER >= 26
+    assert(test_ref());
+    static_assert(test_ref());
+#endif
+
     return 0;
 }

diff  --git a/libcxx/test/std/utilities/optional/optional.object/optional.object.observe/dereference_rvalue.pass.cpp b/libcxx/test/std/utilities/optional/optional.object/optional.object.observe/dereference_rvalue.pass.cpp
index 16bf2e4336c69..9c394bb13a2a0 100644
--- a/libcxx/test/std/utilities/optional/optional.object/optional.object.observe/dereference_rvalue.pass.cpp
+++ b/libcxx/test/std/utilities/optional/optional.object/optional.object.observe/dereference_rvalue.pass.cpp
@@ -11,11 +11,13 @@
 
 // constexpr T&& optional<T>::operator*() &&;
 
-#include <optional>
-#include <type_traits>
 #include <cassert>
+#include <optional>
 
 #include "test_macros.h"
+#if TEST_STD_VER >= 26
+#  include "copy_move_types.h"
+#endif
 
 using std::optional;
 
@@ -39,6 +41,40 @@ test()
     return (*std::move(opt)).test();
 }
 
+#if TEST_STD_VER >= 26
+constexpr bool test_ref() {
+  // ensure underlying value isn't moved from
+  {
+    TracedCopyMove x{};
+    std::optional<TracedCopyMove&> opt(x);
+    ASSERT_NOEXCEPT(*std::move(opt));
+    ASSERT_SAME_TYPE(decltype(*std::move(opt)), TracedCopyMove&);
+
+    assert(std::addressof(*std::move(opt)) == std::addressof(x));
+    assert((*std::move(opt)).constMove == 0);
+    assert((*std::move(opt)).nonConstMove == 0);
+    assert((*std::move(opt)).constCopy == 0);
+    assert((*std::move(opt)).nonConstCopy == 0);
+  }
+
+  {
+    TracedCopyMove x{};
+    std::optional<const TracedCopyMove&> opt(x);
+    ASSERT_NOEXCEPT(*std::move(opt));
+    ASSERT_SAME_TYPE(decltype(*std::move(opt)), const TracedCopyMove&);
+
+    assert(std::addressof(*std::move(opt)) == std::addressof(x));
+    assert((*std::move(opt)).constMove == 0);
+    assert((*std::move(opt)).nonConstMove == 0);
+    assert((*std::move(opt)).constCopy == 0);
+    assert((*std::move(opt)).nonConstCopy == 0);
+  }
+
+  return true;
+}
+
+#endif
+
 int main(int, char**)
 {
     {
@@ -52,5 +88,10 @@ int main(int, char**)
     }
     static_assert(test() == 7, "");
 
+#if TEST_STD_VER >= 26
+    assert(test_ref());
+    static_assert(test_ref());
+#endif
+
     return 0;
 }

diff  --git a/libcxx/test/std/utilities/optional/optional.object/optional.object.observe/has_value.pass.cpp b/libcxx/test/std/utilities/optional/optional.object/optional.object.observe/has_value.pass.cpp
index 9873a767cfbe6..d8c424fc41c74 100644
--- a/libcxx/test/std/utilities/optional/optional.object/optional.object.observe/has_value.pass.cpp
+++ b/libcxx/test/std/utilities/optional/optional.object/optional.object.observe/has_value.pass.cpp
@@ -11,9 +11,8 @@
 
 // constexpr bool optional<T>::has_value() const noexcept;
 
-#include <optional>
-#include <type_traits>
 #include <cassert>
+#include <optional>
 
 #include "test_macros.h"
 
@@ -37,8 +36,13 @@ int main(int, char**)
     {
       static constexpr int i = 0;
       constexpr optional<const int&> opt{i};
+      ASSERT_NOEXCEPT(opt.has_value());
       static_assert(opt.has_value());
     }
+    {
+      constexpr optional<const int&> opt{};
+      static_assert(!opt.has_value());
+    }
 #endif
 
     return 0;

diff  --git a/libcxx/test/std/utilities/optional/optional.object/optional.object.observe/op_arrow.pass.cpp b/libcxx/test/std/utilities/optional/optional.object/optional.object.observe/op_arrow.pass.cpp
index 96d22743ac7fe..bb050f20debe1 100644
--- a/libcxx/test/std/utilities/optional/optional.object/optional.object.observe/op_arrow.pass.cpp
+++ b/libcxx/test/std/utilities/optional/optional.object/optional.object.observe/op_arrow.pass.cpp
@@ -11,9 +11,9 @@
 
 // constexpr T* optional<T>::operator->();
 
-#include <optional>
-#include <type_traits>
 #include <cassert>
+#include <memory>
+#include <optional>
 
 #include "test_macros.h"
 
@@ -53,17 +53,20 @@ int main(int, char**)
       std::optional<X&> opt(x);
       ASSERT_SAME_TYPE(decltype(opt.operator->()), X*);
       ASSERT_NOEXCEPT(opt.operator->());
+      assert(opt.operator->() == std::addressof(x));
     }
     {
       X x{};
       std::optional<const X&> opt(x);
       ASSERT_SAME_TYPE(decltype(opt.operator->()), const X*);
       ASSERT_NOEXCEPT(opt.operator->());
+      assert(opt.operator->() == std::addressof(x));
     }
     {
       X x{};
       optional<X&> opt{x};
       assert(opt->test() == 3);
+      assert(opt.operator->() == std::addressof(x));
     }
     {
       X x{};

diff  --git a/libcxx/test/std/utilities/optional/optional.object/optional.object.observe/op_arrow_const.pass.cpp b/libcxx/test/std/utilities/optional/optional.object/optional.object.observe/op_arrow_const.pass.cpp
index e9694fd6d9640..0461a04b85d45 100644
--- a/libcxx/test/std/utilities/optional/optional.object/optional.object.observe/op_arrow_const.pass.cpp
+++ b/libcxx/test/std/utilities/optional/optional.object/optional.object.observe/op_arrow_const.pass.cpp
@@ -11,9 +11,9 @@
 
 // constexpr const T* optional<T>::operator->() const;
 
-#include <optional>
-#include <type_traits>
 #include <cassert>
+#include <memory>
+#include <optional>
 
 #include "test_macros.h"
 
@@ -60,17 +60,20 @@ int main(int, char**)
       const std::optional<X&> opt(x);
       ASSERT_SAME_TYPE(decltype(opt.operator->()), X*);
       ASSERT_NOEXCEPT(opt.operator->());
+      assert(opt.operator->() == std::addressof(x));
     }
     {
       X x{};
       const std::optional<const X&> opt(x);
       ASSERT_SAME_TYPE(decltype(opt.operator->()), const X*);
       ASSERT_NOEXCEPT(opt.operator->());
+      assert(opt.operator->() == std::addressof(x));
     }
     {
       static constexpr Z z{};
       constexpr optional<const Z&> opt(z);
       static_assert(opt->test() == 1);
+      static_assert(opt.operator->() == std::addressof(z));
     }
 #endif
 

diff  --git a/libcxx/test/std/utilities/optional/optional.object/optional.object.observe/value_const.pass.cpp b/libcxx/test/std/utilities/optional/optional.object/optional.object.observe/value_const.pass.cpp
index ea62f76d4082a..044134126a374 100644
--- a/libcxx/test/std/utilities/optional/optional.object/optional.object.observe/value_const.pass.cpp
+++ b/libcxx/test/std/utilities/optional/optional.object/optional.object.observe/value_const.pass.cpp
@@ -12,11 +12,14 @@
 
 // constexpr const T& optional<T>::value() const &;
 
-#include <optional>
-#include <type_traits>
 #include <cassert>
+#include <memory>
+#include <optional>
 
 #include "test_macros.h"
+#if TEST_STD_VER >= 26
+#  include "copy_move_types.h"
+#endif
 
 using std::optional;
 using std::in_place_t;
@@ -33,6 +36,38 @@ struct X
     int test() && {return 6;}
 };
 
+#if TEST_STD_VER >= 26
+constexpr bool test_ref() {
+  {
+    TracedCopyMove x{};
+    const std::optional<TracedCopyMove&> opt(x);
+    ASSERT_NOT_NOEXCEPT(opt.value());
+    ASSERT_SAME_TYPE(decltype(opt.value()), TracedCopyMove&);
+
+    assert(std::addressof(opt.value()) == std::addressof(x));
+    assert(opt->constMove == 0);
+    assert(opt->nonConstMove == 0);
+    assert(opt->constCopy == 0);
+    assert(opt->nonConstCopy == 0);
+  }
+
+  {
+    TracedCopyMove x{};
+    const std::optional<const TracedCopyMove&> opt(x);
+    ASSERT_NOT_NOEXCEPT(opt.value());
+    ASSERT_SAME_TYPE(decltype(opt.value()), const TracedCopyMove&);
+
+    assert(std::addressof(opt.value()) == std::addressof(x));
+    assert(opt->constMove == 0);
+    assert(opt->nonConstMove == 0);
+    assert(opt->constCopy == 0);
+    assert(opt->nonConstCopy == 0);
+  }
+
+  return true;
+}
+#endif
+
 int main(int, char**)
 {
     {
@@ -62,5 +97,10 @@ int main(int, char**)
     }
 #endif
 
-  return 0;
+#if TEST_STD_VER >= 26
+    assert(test_ref());
+    static_assert(test_ref());
+#endif
+
+    return 0;
 }

diff  --git a/libcxx/test/std/utilities/optional/optional.object/optional.object.observe/value_const_rvalue.pass.cpp b/libcxx/test/std/utilities/optional/optional.object/optional.object.observe/value_const_rvalue.pass.cpp
index 49dbe4e58b57d..66911bf85f5fe 100644
--- a/libcxx/test/std/utilities/optional/optional.object/optional.object.observe/value_const_rvalue.pass.cpp
+++ b/libcxx/test/std/utilities/optional/optional.object/optional.object.observe/value_const_rvalue.pass.cpp
@@ -12,11 +12,14 @@
 
 // constexpr const T& optional<T>::value() const &&;
 
+#include <cassert>
 #include <optional>
 #include <type_traits>
-#include <cassert>
 
 #include "test_macros.h"
+#if TEST_STD_VER >= 26
+#  include "copy_move_types.h"
+#endif
 
 using std::optional;
 using std::in_place_t;
@@ -33,6 +36,40 @@ struct X
     int test() && {return 6;}
 };
 
+#if TEST_STD_VER >= 26
+constexpr bool test_ref() {
+  {
+    TracedCopyMove x{};
+    const std::optional<TracedCopyMove&> opt(x);
+    ASSERT_NOT_NOEXCEPT(std::move(opt).value());
+    ASSERT_SAME_TYPE(decltype(std::move(opt).value()), TracedCopyMove&);
+
+    assert(std::addressof(std::move(opt).value()) == std::addressof(x));
+    auto& val = std::move(opt).value();
+    assert(val.constMove == 0);
+    assert(val.nonConstMove == 0);
+    assert(val.constCopy == 0);
+    assert(val.nonConstCopy == 0);
+  }
+
+  {
+    TracedCopyMove x{};
+    const std::optional<const TracedCopyMove&> opt(x);
+    ASSERT_NOT_NOEXCEPT(std::move(opt).value());
+    ASSERT_SAME_TYPE(decltype(std::move(opt).value()), const TracedCopyMove&);
+
+    assert(std::addressof(std::move(opt).value()) == std::addressof(x));
+    auto& val = std::move(opt).value();
+    assert(val.constMove == 0);
+    assert(val.nonConstMove == 0);
+    assert(val.constCopy == 0);
+    assert(val.nonConstCopy == 0);
+  }
+
+  return true;
+}
+#endif
+
 int main(int, char**)
 {
     {
@@ -61,6 +98,9 @@ int main(int, char**)
         }
     }
 #endif
-
-  return 0;
+#if TEST_STD_VER >= 26
+    assert(test_ref());
+    static_assert(test_ref());
+#endif
+    return 0;
 }

diff  --git a/libcxx/test/std/utilities/optional/optional.object/optional.object.observe/value_or.pass.cpp b/libcxx/test/std/utilities/optional/optional.object/optional.object.observe/value_or.pass.cpp
index 66890ff9c9b91..f4ad896ed9816 100644
--- a/libcxx/test/std/utilities/optional/optional.object/optional.object.observe/value_or.pass.cpp
+++ b/libcxx/test/std/utilities/optional/optional.object/optional.object.observe/value_or.pass.cpp
@@ -84,6 +84,7 @@ constexpr int test()
     {
       int y = 2;
       optional<int&> opt;
+      ASSERT_SAME_TYPE(decltype(std::move(opt).value_or(y)), int);
       assert(std::move(opt).value_or(y) == 2);
       assert(!opt);
     }
@@ -93,7 +94,8 @@ constexpr int test()
 
 int main(int, char**)
 {
-    static_assert(test() == 0);
+  assert(test() == 0);
+  static_assert(test() == 0);
 
   return 0;
 }

diff  --git a/libcxx/test/std/utilities/optional/optional.object/optional.object.swap/swap.pass.cpp b/libcxx/test/std/utilities/optional/optional.object/optional.object.swap/swap.pass.cpp
index a82ca615e0c8c..afc1617affe3a 100644
--- a/libcxx/test/std/utilities/optional/optional.object/optional.object.swap/swap.pass.cpp
+++ b/libcxx/test/std/utilities/optional/optional.object/optional.object.swap/swap.pass.cpp
@@ -397,6 +397,51 @@ int main(int, char**)
         assert(static_cast<bool>(opt2) == true);
         assert(*opt2 == 2);
     }
+
+#  if TEST_STD_VER >= 26
+    {
+      Z z{1};
+      optional<Z&> opt1{z};
+      optional<Z&> opt2;
+      ASSERT_NOEXCEPT(opt1.swap(opt2));
+      assert(opt1);
+      assert(*opt1 == 1);
+      assert(&(*opt1) == &z);
+      assert(!opt2);
+
+      opt1.swap(opt2);
+      assert(*opt2 == 1);
+      assert(&(*opt2) == &z);
+      assert(opt2 && !opt1);
+    }
+
+    {
+      Z z1{1};
+      optional<Z&> opt1;
+      optional<Z&> opt2{z1};
+      ASSERT_NOEXCEPT(opt1.swap(opt2));
+
+      opt1.swap(opt2);
+      assert(opt1 && !opt2);
+      assert(*opt1 == 1);
+      assert(&(*opt1) == &z1);
+    }
+
+    {
+      Z z1{1};
+      Z z2{2};
+      optional<Z&> opt1{z1};
+      optional<Z&> opt2{z2};
+      ASSERT_NOEXCEPT(opt1.swap(opt2));
+
+      opt1.swap(opt2);
+      assert(opt1 && opt2);
+      assert(*opt1 == 2);
+      assert(*opt2 == 1);
+      assert(&(*opt1) == &z2);
+      assert(&(*opt2) == &z1);
+    }
+#  endif
 #endif
 
   return 0;

diff  --git a/libcxx/test/std/utilities/optional/optional.object/optional_helper_types.h b/libcxx/test/std/utilities/optional/optional.object/optional_helper_types.h
new file mode 100644
index 0000000000000..704d99acb15e9
--- /dev/null
+++ b/libcxx/test/std/utilities/optional/optional.object/optional_helper_types.h
@@ -0,0 +1,54 @@
+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+// TODO: We should consolidate all the helper types used in the optional tests into here.
+
+#include "test_macros.h"
+
+#ifndef LIBCXX_UTILITIES_OPTIONAL_HELPER_TYPES_H
+#  define LIBCXX_UTILITIES_OPTIONAL_HELPER_TYPES_H
+
+template <typename T>
+struct ReferenceConversion {
+  T lvalue;
+  T rvalue;
+
+  constexpr ReferenceConversion(T lval, T rval) : lvalue(lval), rvalue(rval) {}
+
+  constexpr operator T&() & noexcept { return lvalue; }
+
+  constexpr operator T&() && noexcept { return rvalue; }
+};
+
+template <typename T>
+struct ReferenceConversionThrows {
+  T lvalue;
+  T rvalue;
+  bool throws{false};
+
+  constexpr ReferenceConversionThrows(T lval, T rval, bool except = false)
+      : lvalue(lval), rvalue(rval), throws(except) {}
+
+  constexpr operator T&() & {
+    if (throws) {
+      TEST_THROW(1);
+    }
+
+    return lvalue;
+  }
+
+  constexpr operator T&() && {
+    if (throws) {
+      TEST_THROW(2);
+    }
+
+    return rvalue;
+  }
+};
+
+#endif


        


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