Index: .gitignore
===================================================================
--- .gitignore
+++ .gitignore
@@ -56,3 +56,6 @@
 # MSVC libraries test harness
 env.lst
 keep.lst
+
+# Editor by-products
+.vscode/
Index: include/experimental/optional
===================================================================
--- include/experimental/optional
+++ include/experimental/optional
@@ -8,8 +8,8 @@
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef _LIBCPP_OPTIONAL
-#define _LIBCPP_OPTIONAL
+#ifndef _LIBCPP_EXPERIMENTAL_OPTIONAL
+#define _LIBCPP_EXPERIMENTAL_OPTIONAL
 
 /*
     optional synopsis
@@ -899,4 +899,4 @@
 
 #endif  // _LIBCPP_STD_VER > 11
 
-#endif  // _LIBCPP_OPTIONAL
+#endif  // _LIBCPP_EXPERIMENTAL_OPTIONAL
Index: include/optional
===================================================================
--- /dev/null
+++ include/optional
@@ -0,0 +1,1144 @@
+// -*- C++ -*-
+//===-------------------------- optional ----------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_OPTIONAL
+#define _LIBCPP_OPTIONAL
+
+/*
+    optional synopsis
+
+// C++1z
+
+namespace std {
+  // 20.6.3, optional for object types
+  template <class T> class optional;
+
+  // 20.6.4, no-value state indicator
+  struct nullopt_t{see below };
+  constexpr nullopt_t nullopt(unspecified );
+
+  // 20.6.5, class bad_optional_access
+  class bad_optional_access;
+
+  // 20.6.6, relational operators
+  template <class T>
+  constexpr bool operator==(const optional<T>&, const optional<T>&);
+  template <class T>
+  constexpr bool operator!=(const optional<T>&, const optional<T>&);
+  template <class T>
+  constexpr bool operator<(const optional<T>&, const optional<T>&);
+  template <class T>
+  constexpr bool operator>(const optional<T>&, const optional<T>&);
+  template <class T>
+  constexpr bool operator<=(const optional<T>&, const optional<T>&);
+  template <class T>
+  constexpr bool operator>=(const optional<T>&, const optional<T>&);
+  template <class T> constexpr bool operator==(const optional<T>&, nullopt_t) noexcept;
+  template <class T> constexpr bool operator==(nullopt_t, const optional<T>&) noexcept;
+  template <class T> constexpr bool operator!=(const optional<T>&, nullopt_t) noexcept;
+  template <class T> constexpr bool operator!=(nullopt_t, const optional<T>&) noexcept;
+  template <class T> constexpr bool operator<(const optional<T>&, nullopt_t) noexcept;
+  template <class T> constexpr bool operator<(nullopt_t, const optional<T>&) noexcept;
+  template <class T> constexpr bool operator<=(const optional<T>&, nullopt_t) noexcept;
+  template <class T> constexpr bool operator<=(nullopt_t, const optional<T>&) noexcept;
+  template <class T> constexpr bool operator>(const optional<T>&, nullopt_t) noexcept;
+  template <class T> constexpr bool operator>(nullopt_t, const optional<T>&) noexcept;
+  template <class T> constexpr bool operator>=(const optional<T>&, nullopt_t) noexcept;
+  template <class T> constexpr bool operator>=(nullopt_t, const optional<T>&) noexcept;
+
+  // 20.6.8, comparison with T
+  template <class T> constexpr bool operator==(const optional<T>&, const T&);
+  template <class T> constexpr bool operator==(const T&, const optional<T>&);
+  template <class T> constexpr bool operator!=(const optional<T>&, const T&);
+  template <class T> constexpr bool operator!=(const T&, const optional<T>&);
+  template <class T> constexpr bool operator<(const optional<T>&, const T&);
+  template <class T> constexpr bool operator<(const T&, const optional<T>&);
+  template <class T> constexpr bool operator<=(const optional<T>&, const T&);
+  template <class T> constexpr bool operator<=(const T&, const optional<T>&);
+  template <class T> constexpr bool operator>(const optional<T>&, const T&);
+  template <class T> constexpr bool operator>(const T&, const optional<T>&);
+  template <class T> constexpr bool operator>=(const optional<T>&, const T&);
+  template <class T> constexpr bool operator>=(const T&, const optional<T>&);
+
+  // 20.6.9, specialized algorithms
+  template <class T> void swap(optional<T>&, optional<T>&) noexcept(see below );
+  template <class T> constexpr optional<see below > make_optional(T&&);
+  template <class T, class... Args>
+    constexpr optional<T> make_optional(Args&&... args);
+  template <class T, class U, class... Args>
+    constexpr optional<T> make_optional(initializer_list<U> il, Args&&... args);
+
+  // 20.6.10, hash support
+  template <class T> struct hash;
+  template <class T> struct hash<optional<T>>;
+
+  template <class T> class optional {
+  public:
+    using value_type = T;
+
+    // 20.6.3.1, constructors
+    constexpr optional() noexcept;
+    constexpr optional(nullopt_t) noexcept;
+    optional(const optional &);
+    optional(optional &&) noexcept(see below );
+    template <class... Args> constexpr explicit optional(in_place_t, Args &&...);
+    template <class U, class... Args>
+      constexpr explicit optional(in_place_t, initializer_list<U>, Args &&...);
+    template <class U = T>
+      constexpr EXPLICIT optional(U &&);
+    template <class U>
+      constexpr EXPLICIT optional(const optional<U> &);
+    template <class U>
+      constexpr EXPLICIT optional(optional<U> &&);
+
+    // 20.6.3.2, destructor
+    ~optional();
+
+    // 20.6.3.3, assignment
+    optional &operator=(nullopt_t) noexcept;
+    optional &operator=(const optional &);
+    optional &operator=(optional &&) noexcept(see below );
+    template <class U = T> optional &operator=(U &&);
+    template <class U> optional &operator=(const optional<U> &);
+    template <class U> optional &operator=(optional<U> &&);
+    template <class... Args> void emplace(Args &&...);
+    template <class U, class... Args>
+      void emplace(initializer_list<U>, Args &&...);
+
+    // 20.6.3.4, swap
+    void swap(optional &) noexcept(see below );
+
+    // 20.6.3.5, observers
+    constexpr T const *operator->() const;
+    constexpr T *operator->();
+    constexpr T const &operator*() const &;
+    constexpr T &operator*() &;
+    constexpr T &&operator*() &&;
+    constexpr const T &&operator*() const &&;
+    constexpr explicit operator bool() const noexcept;
+    constexpr bool has_value() const noexcept;
+    constexpr T const &value() const &;
+    constexpr T &value() &;
+    constexpr T &&value() &&;
+    constexpr const T &&value() const &&;
+    template <class U> constexpr T value_or(U &&) const &;
+    template <class U> constexpr T value_or(U &&) &&;
+
+    // 20.6.3.6, modifiers
+    void reset() noexcept;
+
+  private:
+    T *val; // exposition only
+  };
+} // namespace std
+
+*/
+
+#include <__config>
+#include <__debug>
+#include <__functional_base>
+#include <__undef_min_max>
+#include <functional>
+#include <initializer_list>
+#include <new>
+#include <stdexcept>
+#include <type_traits>
+#include <utility>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+namespace std  // purposefully not using versioning namespace
+{
+
+class _LIBCPP_EXCEPTION_ABI bad_optional_access
+    : public logic_error
+{
+public:
+    _LIBCPP_INLINE_VISIBILITY
+    bad_optional_access() : logic_error("Bad optional access") {}
+
+    // Get the key function ~bad_optional_access() into the dylib
+    virtual ~bad_optional_access() _NOEXCEPT;
+};
+
+}  // std
+
+#if _LIBCPP_STD_VER > 14
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+struct nullopt_t
+{
+    struct __secret_tag { _LIBCPP_INLINE_VISIBILITY explicit __secret_tag() = default; };
+    _LIBCPP_INLINE_VISIBILITY constexpr explicit nullopt_t(__secret_tag, __secret_tag) noexcept {}
+};
+
+/* inline */ constexpr nullopt_t nullopt{nullopt_t::__secret_tag{}, nullopt_t::__secret_tag{}};
+
+template <class _Tp, bool = is_trivially_destructible_v<_Tp>>
+struct __optional_destruct_base;
+
+template <class _Tp>
+struct __optional_destruct_base<_Tp, false>
+{
+    typedef _Tp value_type;
+    union
+    {
+        char __null_state_;
+        value_type __val_;
+    };
+    bool __engaged_;
+
+    _LIBCPP_INLINE_VISIBILITY
+    ~__optional_destruct_base()
+    {
+        if (__engaged_)
+            __val_.~value_type();
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    constexpr __optional_destruct_base() noexcept
+        :  __null_state_(),
+           __engaged_(false) {}
+
+    template <class... _Args>
+    _LIBCPP_INLINE_VISIBILITY
+    constexpr explicit __optional_destruct_base(in_place_t, _Args&&... __args)
+        :  __val_(_VSTD::forward<_Args>(__args)...),
+           __engaged_(true) {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    void reset() noexcept
+    {
+        if (__engaged_)
+        {
+            __val_.~value_type();
+            __engaged_ = false;
+        }
+    }
+};
+
+template <class _Tp>
+struct __optional_destruct_base<_Tp, true>
+{
+    typedef _Tp value_type;
+    union
+    {
+        char __null_state_;
+        value_type __val_;
+    };
+    bool __engaged_;
+
+    _LIBCPP_INLINE_VISIBILITY
+    constexpr __optional_destruct_base() noexcept
+        :  __null_state_(),
+           __engaged_(false) {}
+
+    template <class... _Args>
+    _LIBCPP_INLINE_VISIBILITY
+    constexpr explicit __optional_destruct_base(in_place_t, _Args&&... __args)
+        :  __val_(_VSTD::forward<_Args>(__args)...),
+           __engaged_(true) {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    void reset() noexcept
+    {
+        if (__engaged_)
+        {
+            __engaged_ = false;
+        }
+    }
+};
+
+template <class _Tp>
+struct __optional_storage_base : __optional_destruct_base<_Tp>
+{
+    using __base = __optional_destruct_base<_Tp>;
+    using typename __base::value_type;
+    using __base::__base;
+
+    _LIBCPP_INLINE_VISIBILITY
+    constexpr bool has_value() const noexcept
+    {
+        return this->__engaged_;
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    constexpr value_type& __get() & noexcept
+    {
+        return this->__val_;
+    }
+    _LIBCPP_INLINE_VISIBILITY
+    constexpr const value_type& __get() const& noexcept
+    {
+        return this->__val_;
+    }
+    _LIBCPP_INLINE_VISIBILITY
+    constexpr value_type&& __get() && noexcept
+    {
+        return _VSTD::move(this->__val_);
+    }
+    _LIBCPP_INLINE_VISIBILITY
+    constexpr const value_type&& __get() const&& noexcept
+    {
+        return _VSTD::move(this->__val_);
+    }
+
+    template <class... _Args>
+    _LIBCPP_INLINE_VISIBILITY
+    void __construct(_Args&&... __args)
+    {
+        _LIBCPP_ASSERT(!has_value(), "__construct called for engaged __optional_storage");
+        ::new(_VSTD::addressof(this->__val_)) value_type(_VSTD::forward<_Args>(__args)...);
+        this->__engaged_ = true;
+    }
+
+    template <class _That>
+    _LIBCPP_INLINE_VISIBILITY
+    void __construct_from(_That&& __opt)
+    {
+        if (__opt.has_value())
+            __construct(_VSTD::forward<_That>(__opt).__get());
+    }
+
+    template <class _That>
+    _LIBCPP_INLINE_VISIBILITY
+    void __assign_from(_That&& __opt)
+    {
+        if (this->__engaged_ == __opt.has_value())
+        {
+            if (this->__engaged_)
+                this->__val_ = _VSTD::forward<_That>(__opt).__get();
+        }
+        else
+        {
+            if (this->__engaged_)
+                this->reset();
+            else
+                __construct(_VSTD::forward<_That>(__opt).__get());
+        }
+    }
+};
+
+template <class _Tp, bool = is_trivially_copyable_v<_Tp>>
+struct __optional_storage;
+
+template <class _Tp>
+struct __optional_storage<_Tp, true> : __optional_storage_base<_Tp>
+{
+    using __optional_storage_base<_Tp>::__optional_storage_base;
+};
+
+template <class _Tp>
+struct __optional_storage<_Tp, false> : __optional_storage_base<_Tp>
+{
+    using typename __optional_storage_base<_Tp>::value_type;
+    using __optional_storage_base<_Tp>::__optional_storage_base;
+
+    _LIBCPP_INLINE_VISIBILITY
+    __optional_storage() = default;
+
+    _LIBCPP_INLINE_VISIBILITY
+    __optional_storage(const __optional_storage& __opt)
+    {
+        this->__construct_from(__opt);
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    __optional_storage(__optional_storage&& __opt)
+        noexcept(is_nothrow_move_constructible_v<value_type>)
+    {
+        this->__construct_from(_VSTD::move(__opt));
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    __optional_storage& operator=(const __optional_storage& __opt)
+    {
+        this->__assign_from(__opt);
+        return *this;
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    __optional_storage& operator=(__optional_storage&& __opt)
+        noexcept(is_nothrow_move_assignable_v<value_type> &&
+                 is_nothrow_move_constructible_v<value_type>)
+    {
+        this->__assign_from(_VSTD::move(__opt));
+        return *this;
+    }
+};
+
+template <class _Tp, template <class...> class _Template>
+constexpr bool _Is_specialization = false;
+template <class... _Args, template <class...> class _Template>
+constexpr bool _Is_specialization<_Template<_Args...>, _Template> = true;
+
+template <class _Tp>
+using __optional_sfinae_ctor_base_t = __sfinae_ctor_base<
+    is_copy_constructible<_Tp>::value,
+    is_move_constructible<_Tp>::value
+>;
+
+template <class _Tp>
+using __optional_sfinae_assign_base_t = __sfinae_assign_base<
+    (is_copy_constructible<_Tp>::value && is_copy_assignable<_Tp>::value),
+    (is_move_constructible<_Tp>::value && is_move_assignable<_Tp>::value) ||
+        (is_copy_constructible<_Tp>::value && is_copy_assignable<_Tp>::value)
+>;
+
+template <class _Tp>
+class optional
+    : __optional_storage<_Tp>
+    , __optional_sfinae_ctor_base_t<_Tp>
+    , __optional_sfinae_assign_base_t<_Tp>
+{
+public:
+    using __base = __optional_storage<_Tp>;
+    using typename __base::value_type;
+
+    static_assert(!is_reference_v<value_type>,
+        "Instantiation of optional with a reference type is ill-formed.");
+    static_assert(!is_same_v<remove_cv_t<value_type>, nullopt_t>,
+        "Instantiation of optional with a nullopt_t type is ill-formed.");
+    static_assert(is_reference_v<value_type> || is_object_v<value_type>,
+        "Instantiation of optional with a non-object type is undefined behavior.");
+
+    _LIBCPP_INLINE_VISIBILITY constexpr optional() noexcept {}
+    _LIBCPP_INLINE_VISIBILITY optional(const optional&) = default;
+    _LIBCPP_INLINE_VISIBILITY optional(optional&&) = default;
+    _LIBCPP_INLINE_VISIBILITY constexpr optional(nullopt_t) noexcept {}
+
+    template <class... _Args,
+              class = enable_if_t
+                      <
+                           is_constructible_v<value_type, _Args...>
+                      >
+             >
+    _LIBCPP_INLINE_VISIBILITY
+    constexpr explicit optional(in_place_t, _Args&&... __args)
+        : __base(in_place, _VSTD::forward<_Args>(__args)...) {}
+
+    template <class _Up, class... _Args,
+              class = enable_if_t
+                      <
+                           is_constructible_v<value_type, initializer_list<_Up>&, _Args...>
+                      >
+             >
+    _LIBCPP_INLINE_VISIBILITY
+    constexpr explicit optional(in_place_t, initializer_list<_Up> __il, _Args&&... __args)
+        : __base(in_place, __il, _VSTD::forward<_Args>(__args)...) {}
+
+    // LWG2756: conditionally explicit conversion from _Up
+    template <class _Up>
+    using _AllowDirectConversion = typename conjunction<
+        negation<bool_constant<_Is_specialization<decay_t<_Up>, _VSTD::optional>>>,
+        negation<is_same<_Up, in_place_t>>,
+        is_constructible<value_type, _Up>>::type;
+    template <class _Up = value_type, enable_if_t<conjunction_v<
+        _AllowDirectConversion<_Up>, is_convertible<_Up, value_type>>, int> = 0>
+    _LIBCPP_INLINE_VISIBILITY
+    constexpr optional(_Up&& __v)
+        : __base(in_place, _VSTD::forward<_Up>(__v)) {}
+    template <class _Up, enable_if_t<conjunction_v<
+        _AllowDirectConversion<_Up>, negation<is_convertible<_Up, value_type>>>, int> = 0>
+    _LIBCPP_INLINE_VISIBILITY
+    constexpr explicit optional(_Up&& __v)
+        : __base(in_place, _VSTD::forward<_Up>(__v)) {}
+
+    // LWG2756: conditionally explicit conversion from const optional<_Up>&
+    template <class _Up, enable_if_t<
+        is_constructible_v<value_type, const _Up&> &&
+        is_convertible_v<const _Up&, value_type>, int> = 0>
+    _LIBCPP_INLINE_VISIBILITY
+    optional(const optional<_Up>& __v)
+    {
+        this->__construct_from(__v);
+    }
+    template <class _Up, enable_if_t<
+        is_constructible_v<value_type, const _Up&> &&
+        !is_convertible_v<const _Up&, value_type>, int> = 0>
+    _LIBCPP_INLINE_VISIBILITY
+    explicit optional(const optional<_Up>& __v)
+    {
+        this->__construct_from(__v);
+    }
+
+    // LWG2756: conditionally explicit conversion from optional<_Up>&&
+    template <class _Up, enable_if_t<
+        is_constructible_v<value_type, _Up> &&
+        is_convertible_v<_Up, value_type>, int> = 0>
+    _LIBCPP_INLINE_VISIBILITY
+    optional(optional<_Up>&& __v)
+    {
+        this->__construct_from(_VSTD::move(__v));
+    }
+    template <class _Up, enable_if_t<
+        is_constructible_v<value_type, _Up> &&
+        !is_convertible_v<_Up, value_type>, int> = 0>
+    _LIBCPP_INLINE_VISIBILITY
+    explicit optional(optional<_Up>&& __v)
+    {
+        this->__construct_from(_VSTD::move(__v));
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    optional& operator=(nullopt_t) noexcept
+    {
+        reset();
+        return *this;
+    }
+
+    _LIBCPP_INLINE_VISIBILITY optional& operator=(const optional&) = default;
+    _LIBCPP_INLINE_VISIBILITY optional& operator=(optional&&) = default;
+
+    // LWG2756
+    template <class _Up = value_type,
+              class = enable_if_t
+                      <
+                          !_Is_specialization<_Up, _VSTD::optional> &&
+                          is_constructible_v<value_type, _Up> &&
+                          is_assignable_v<value_type&, _Up>
+                      >
+             >
+    _LIBCPP_INLINE_VISIBILITY
+    optional&
+    operator=(_Up&& __v)
+    {
+        if (this->has_value())
+            this->__get() = _VSTD::forward<_Up>(__v);
+        else
+            this->__construct(_VSTD::forward<_Up>(__v));
+        return *this;
+    }
+
+    // LWG2756
+    template <class _Up,
+              class = enable_if_t
+                      <
+                          is_constructible_v<value_type, const _Up&> &&
+                          is_assignable_v<value_type&, const _Up&>
+                      >
+             >
+    _LIBCPP_INLINE_VISIBILITY
+    optional&
+    operator=(const optional<_Up>& __v)
+    {
+        this->__assign_from(__v);
+        return *this;
+    }
+
+    // LWG2756
+    template <class _Up,
+              class = enable_if_t
+                      <
+                          is_constructible_v<value_type, _Up> &&
+                          is_assignable_v<value_type&, _Up>
+                      >
+             >
+    _LIBCPP_INLINE_VISIBILITY
+    optional&
+    operator=(optional<_Up>&& __v)
+    {
+        this->__assign_from(_VSTD::move(__v));
+        return *this;
+    }
+
+    template <class... _Args,
+              class = enable_if_t
+                      <
+                          is_constructible_v<value_type, _Args...>
+                      >
+             >
+    _LIBCPP_INLINE_VISIBILITY
+    void
+    emplace(_Args&&... __args)
+    {
+        reset();
+        this->__construct(_VSTD::forward<_Args>(__args)...);
+    }
+
+    template <class _Up, class... _Args,
+              class = enable_if_t
+                      <
+                          is_constructible_v<value_type, initializer_list<_Up>&, _Args...>
+                      >
+             >
+    _LIBCPP_INLINE_VISIBILITY
+    void
+    emplace(initializer_list<_Up> __il, _Args&&... __args)
+    {
+        reset();
+        this->__construct(__il, _VSTD::forward<_Args>(__args)...);
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    void
+    swap(optional& __opt)
+        noexcept(is_nothrow_move_constructible_v<value_type> &&
+                 is_nothrow_swappable_v<value_type>)
+    {
+        if (this->has_value() == __opt.has_value())
+        {
+            using _VSTD::swap;
+            if (this->has_value())
+                swap(this->__get(), __opt.__get());
+        }
+        else
+        {
+            if (this->has_value())
+            {
+                __opt.__construct(_VSTD::move(this->__get()));
+                reset();
+            }
+            else
+            {
+                this->__construct(_VSTD::move(__opt.__get()));
+                __opt.reset();
+            }
+        }
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    constexpr
+    value_type const*
+    operator->() const
+    {
+        _LIBCPP_ASSERT(this->has_value(), "optional operator-> called for disengaged value");
+#if __has_builtin(__builtin_addressof)
+        return _VSTD::addressof(this->__get());
+#else
+        return __operator_arrow(__has_operator_addressof<value_type>{}, this->__get());
+#endif
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    constexpr
+    value_type*
+    operator->()
+    {
+        _LIBCPP_ASSERT(this->has_value(), "optional operator-> called for disengaged value");
+#if __has_builtin(__builtin_addressof)
+        return _VSTD::addressof(this->__get());
+#else
+        return __operator_arrow(__has_operator_addressof<value_type>{}, this->__get());
+#endif
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    constexpr
+    const value_type&
+    operator*() const&
+    {
+        _LIBCPP_ASSERT(this->has_value(), "optional operator* called for disengaged value");
+        return this->__get();
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    constexpr
+    value_type&
+    operator*() &
+    {
+        _LIBCPP_ASSERT(this->has_value(), "optional operator* called for disengaged value");
+        return this->__get();
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    constexpr
+    value_type&&
+    operator*() &&
+    {
+        _LIBCPP_ASSERT(this->has_value(), "optional operator* called for disengaged value");
+        return _VSTD::move(this->__get());
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    constexpr
+    const value_type&&
+    operator*() const&&
+    {
+        _LIBCPP_ASSERT(this->has_value(), "optional operator* called for disengaged value");
+        return _VSTD::move(this->__get());
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    constexpr explicit operator bool() const noexcept { return has_value(); }
+
+    using __base::has_value;
+    using __base::__get;
+
+    _LIBCPP_INLINE_VISIBILITY
+    constexpr value_type const& value() const&
+    {
+        if (!this->has_value())
+            __libcpp_throw(bad_optional_access());
+        return this->__get();
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    constexpr value_type& value() &
+    {
+        if (!this->has_value())
+            __libcpp_throw(bad_optional_access());
+        return this->__get();
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    constexpr value_type&& value() &&
+    {
+        if (!this->has_value())
+            __libcpp_throw(bad_optional_access());
+        return _VSTD::move(this->__get());
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    constexpr value_type const&& value() const&&
+    {
+        if (!this->has_value())
+            __libcpp_throw(bad_optional_access());
+        return _VSTD::move(this->__get());
+    }
+
+    template <class _Up>
+    _LIBCPP_INLINE_VISIBILITY
+    constexpr value_type value_or(_Up&& __v) const&
+    {
+        static_assert(is_copy_constructible_v<value_type>,
+                      "optional<T>::value_or: T must be copy constructible");
+        static_assert(is_convertible_v<_Up, value_type>,
+                      "optional<T>::value_or: U must be convertible to T");
+        return this->has_value() ? this->__get() :
+                                  static_cast<value_type>(_VSTD::forward<_Up>(__v));
+    }
+
+    template <class _Up>
+    _LIBCPP_INLINE_VISIBILITY
+    value_type value_or(_Up&& __v) &&
+    {
+        static_assert(is_move_constructible_v<value_type>,
+                      "optional<T>::value_or: T must be move constructible");
+        static_assert(is_convertible_v<_Up, value_type>,
+                      "optional<T>::value_or: U must be convertible to T");
+        return this->has_value() ? _VSTD::move(this->__get()) :
+                                  static_cast<value_type>(_VSTD::forward<_Up>(__v));
+    }
+
+    using __base::reset;
+
+private:
+    template <class _Up>
+    _LIBCPP_INLINE_VISIBILITY
+    static _Up*
+    __operator_arrow(true_type, _Up& __x)
+    {
+        return _VSTD::addressof(__x);
+    }
+
+    template <class _Up>
+    _LIBCPP_INLINE_VISIBILITY
+    static constexpr _Up*
+    __operator_arrow(false_type, _Up& __x)
+    {
+        return &__x;
+    }
+};
+
+// Comparisons between optionals
+template <class _Tp>
+_LIBCPP_INLINE_VISIBILITY constexpr
+enable_if_t<
+    is_convertible_v<decltype(_VSTD::declval<const _Tp&>() ==
+        _VSTD::declval<const _Tp&>()), bool>,
+    bool
+>
+operator==(const optional<_Tp>& __x, const optional<_Tp>& __y)
+{
+    if (static_cast<bool>(__x) != static_cast<bool>(__y))
+        return false;
+    if (!static_cast<bool>(__x))
+        return true;
+    return *__x == *__y;
+}
+
+template <class _Tp>
+_LIBCPP_INLINE_VISIBILITY constexpr
+enable_if_t<
+    is_convertible_v<decltype(_VSTD::declval<const _Tp&>() !=
+        _VSTD::declval<const _Tp&>()), bool>,
+    bool
+>
+operator!=(const optional<_Tp>& __x, const optional<_Tp>& __y)
+{
+    if (static_cast<bool>(__x) != static_cast<bool>(__y))
+        return true;
+    if (!static_cast<bool>(__x))
+        return false;
+    return *__x != *__y;
+}
+
+template <class _Tp>
+_LIBCPP_INLINE_VISIBILITY constexpr
+enable_if_t<
+    is_convertible_v<decltype(_VSTD::declval<const _Tp&>() <
+        _VSTD::declval<const _Tp&>()), bool>,
+    bool
+>
+operator<(const optional<_Tp>& __x, const optional<_Tp>& __y)
+{
+    if (!static_cast<bool>(__y))
+        return false;
+    if (!static_cast<bool>(__x))
+        return true;
+    return *__x < *__y;
+}
+
+template <class _Tp>
+_LIBCPP_INLINE_VISIBILITY constexpr
+enable_if_t<
+    is_convertible_v<decltype(_VSTD::declval<const _Tp&>() >
+        _VSTD::declval<const _Tp&>()), bool>,
+    bool
+>
+operator>(const optional<_Tp>& __x, const optional<_Tp>& __y)
+{
+    if (!static_cast<bool>(__x))
+        return false;
+    if (!static_cast<bool>(__y))
+        return true;
+    return *__x > *__y;
+}
+
+template <class _Tp>
+_LIBCPP_INLINE_VISIBILITY constexpr
+enable_if_t<
+    is_convertible_v<decltype(_VSTD::declval<const _Tp&>() <=
+        _VSTD::declval<const _Tp&>()), bool>,
+    bool
+>
+operator<=(const optional<_Tp>& __x, const optional<_Tp>& __y)
+{
+    if (!static_cast<bool>(__x))
+        return true;
+    if (!static_cast<bool>(__y))
+        return false;
+    return *__x <= *__y;
+}
+
+template <class _Tp>
+_LIBCPP_INLINE_VISIBILITY constexpr
+enable_if_t<
+    is_convertible_v<decltype(_VSTD::declval<const _Tp&>() >=
+        _VSTD::declval<const _Tp&>()), bool>,
+    bool
+>
+operator>=(const optional<_Tp>& __x, const optional<_Tp>& __y)
+{
+    if (!static_cast<bool>(__y))
+        return true;
+    if (!static_cast<bool>(__x))
+        return false;
+    return *__x >= *__y;
+}
+
+
+// Comparisons with nullopt
+template <class _Tp>
+_LIBCPP_INLINE_VISIBILITY constexpr
+bool
+operator==(const optional<_Tp>& __x, nullopt_t) noexcept
+{
+    return !static_cast<bool>(__x);
+}
+
+template <class _Tp>
+_LIBCPP_INLINE_VISIBILITY constexpr
+bool
+operator==(nullopt_t, const optional<_Tp>& __x) noexcept
+{
+    return !static_cast<bool>(__x);
+}
+
+template <class _Tp>
+_LIBCPP_INLINE_VISIBILITY constexpr
+bool
+operator!=(const optional<_Tp>& __x, nullopt_t) noexcept
+{
+    return static_cast<bool>(__x);
+}
+
+template <class _Tp>
+_LIBCPP_INLINE_VISIBILITY constexpr
+bool
+operator!=(nullopt_t, const optional<_Tp>& __x) noexcept
+{
+    return static_cast<bool>(__x);
+}
+
+template <class _Tp>
+_LIBCPP_INLINE_VISIBILITY constexpr
+bool
+operator<(const optional<_Tp>&, nullopt_t) noexcept
+{
+    return false;
+}
+
+template <class _Tp>
+_LIBCPP_INLINE_VISIBILITY constexpr
+bool
+operator<(nullopt_t, const optional<_Tp>& __x) noexcept
+{
+    return static_cast<bool>(__x);
+}
+
+template <class _Tp>
+_LIBCPP_INLINE_VISIBILITY constexpr
+bool
+operator<=(const optional<_Tp>& __x, nullopt_t) noexcept
+{
+    return !static_cast<bool>(__x);
+}
+
+template <class _Tp>
+_LIBCPP_INLINE_VISIBILITY constexpr
+bool
+operator<=(nullopt_t, const optional<_Tp>& __x) noexcept
+{
+    return true;
+}
+
+template <class _Tp>
+_LIBCPP_INLINE_VISIBILITY constexpr
+bool
+operator>(const optional<_Tp>& __x, nullopt_t) noexcept
+{
+    return static_cast<bool>(__x);
+}
+
+template <class _Tp>
+_LIBCPP_INLINE_VISIBILITY constexpr
+bool
+operator>(nullopt_t, const optional<_Tp>& __x) noexcept
+{
+    return false;
+}
+
+template <class _Tp>
+_LIBCPP_INLINE_VISIBILITY constexpr
+bool
+operator>=(const optional<_Tp>&, nullopt_t) noexcept
+{
+    return true;
+}
+
+template <class _Tp>
+_LIBCPP_INLINE_VISIBILITY constexpr
+bool
+operator>=(nullopt_t, const optional<_Tp>& __x) noexcept
+{
+    return !static_cast<bool>(__x);
+}
+
+// Comparisons with T
+template <class _Tp>
+_LIBCPP_INLINE_VISIBILITY constexpr
+enable_if_t<
+    is_convertible_v<decltype(_VSTD::declval<const _Tp&>() ==
+        _VSTD::declval<const _Tp&>()), bool>,
+    bool
+>
+operator==(const optional<_Tp>& __x, const _Tp& __v)
+{
+    return static_cast<bool>(__x) ? *__x == __v : false;
+}
+
+template <class _Tp>
+_LIBCPP_INLINE_VISIBILITY constexpr
+enable_if_t<
+    is_convertible_v<decltype(_VSTD::declval<const _Tp&>() ==
+        _VSTD::declval<const _Tp&>()), bool>,
+    bool
+>
+operator==(const _Tp& __v, const optional<_Tp>& __x)
+{
+    return static_cast<bool>(__x) ? __v == *__x : false;
+}
+
+template <class _Tp>
+_LIBCPP_INLINE_VISIBILITY constexpr
+enable_if_t<
+    is_convertible_v<decltype(_VSTD::declval<const _Tp&>() !=
+        _VSTD::declval<const _Tp&>()), bool>,
+    bool
+>
+operator!=(const optional<_Tp>& __x, const _Tp& __v)
+{
+    return static_cast<bool>(__x) ? *__x != __v : true;
+}
+
+template <class _Tp>
+_LIBCPP_INLINE_VISIBILITY constexpr
+enable_if_t<
+    is_convertible_v<decltype(_VSTD::declval<const _Tp&>() !=
+        _VSTD::declval<const _Tp&>()), bool>,
+    bool
+>
+operator!=(const _Tp& __v, const optional<_Tp>& __x)
+{
+    return static_cast<bool>(__x) ? __v != *__x : true;
+}
+
+template <class _Tp>
+_LIBCPP_INLINE_VISIBILITY constexpr
+enable_if_t<
+    is_convertible_v<decltype(_VSTD::declval<const _Tp&>() <
+        _VSTD::declval<const _Tp&>()), bool>,
+    bool
+>
+operator<(const optional<_Tp>& __x, const _Tp& __v)
+{
+    return static_cast<bool>(__x) ? *__x < __v : true;
+}
+
+template <class _Tp>
+_LIBCPP_INLINE_VISIBILITY constexpr
+enable_if_t<
+    is_convertible_v<decltype(_VSTD::declval<const _Tp&>() <
+        _VSTD::declval<const _Tp&>()), bool>,
+    bool
+>
+operator<(const _Tp& __v, const optional<_Tp>& __x)
+{
+    return static_cast<bool>(__x) ? __v < *__x : false;
+}
+
+template <class _Tp>
+_LIBCPP_INLINE_VISIBILITY constexpr
+enable_if_t<
+    is_convertible_v<decltype(_VSTD::declval<const _Tp&>() <=
+        _VSTD::declval<const _Tp&>()), bool>,
+    bool
+>
+operator<=(const optional<_Tp>& __x, const _Tp& __v)
+{
+    return static_cast<bool>(__x) ? *__x <= __v : true;
+}
+
+template <class _Tp>
+_LIBCPP_INLINE_VISIBILITY constexpr
+enable_if_t<
+    is_convertible_v<decltype(_VSTD::declval<const _Tp&>() <=
+        _VSTD::declval<const _Tp&>()), bool>,
+    bool
+>
+operator<=(const _Tp& __v, const optional<_Tp>& __x)
+{
+    return static_cast<bool>(__x) ? __v <= *__x : false;
+}
+
+template <class _Tp>
+_LIBCPP_INLINE_VISIBILITY constexpr
+enable_if_t<
+    is_convertible_v<decltype(_VSTD::declval<const _Tp&>() >
+        _VSTD::declval<const _Tp&>()), bool>,
+    bool
+>
+operator>(const optional<_Tp>& __x, const _Tp& __v)
+{
+    return static_cast<bool>(__x) ? *__x > __v : false;
+}
+
+template <class _Tp>
+_LIBCPP_INLINE_VISIBILITY constexpr
+enable_if_t<
+    is_convertible_v<decltype(_VSTD::declval<const _Tp&>() >
+        _VSTD::declval<const _Tp&>()), bool>,
+    bool
+>
+operator>(const _Tp& __v, const optional<_Tp>& __x)
+{
+    return static_cast<bool>(__x) ? __v > *__x : true;
+}
+
+template <class _Tp>
+_LIBCPP_INLINE_VISIBILITY constexpr
+enable_if_t<
+    is_convertible_v<decltype(_VSTD::declval<const _Tp&>() >=
+        _VSTD::declval<const _Tp&>()), bool>,
+    bool
+>
+operator>=(const optional<_Tp>& __x, const _Tp& __v)
+{
+    return static_cast<bool>(__x) ? *__x >= __v : false;
+}
+
+template <class _Tp>
+_LIBCPP_INLINE_VISIBILITY constexpr
+enable_if_t<
+    is_convertible_v<decltype(_VSTD::declval<const _Tp&>() >=
+        _VSTD::declval<const _Tp&>()), bool>,
+    bool
+>
+operator>=(const _Tp& __v, const optional<_Tp>& __x)
+{
+    return static_cast<bool>(__x) ? __v >= *__x : true;
+}
+
+
+template <class _Tp>
+inline _LIBCPP_INLINE_VISIBILITY
+enable_if_t<
+    is_move_constructible_v<_Tp> && is_swappable_v<_Tp>,
+    void
+>
+swap(optional<_Tp>& __x, optional<_Tp>& __y) noexcept(noexcept(__x.swap(__y)))
+{
+    __x.swap(__y);
+}
+
+template <class _Tp>
+_LIBCPP_INLINE_VISIBILITY constexpr
+optional<decay_t<_Tp>> make_optional(_Tp&& __v)
+{
+    return optional<decay_t<_Tp>>(_VSTD::forward<_Tp>(__v));
+}
+
+template <class _Tp, class... _Args>
+_LIBCPP_INLINE_VISIBILITY constexpr
+optional<_Tp> make_optional(_Args&&... __args)
+{
+    return optional<_Tp>(in_place, _VSTD::forward<_Args>(__args)...);
+}
+
+template <class _Tp, class _Up, class... _Args>
+_LIBCPP_INLINE_VISIBILITY constexpr
+optional<_Tp> make_optional(initializer_list<_Up> __il,  _Args&&... __args)
+{
+    return optional<_Tp>(in_place, __il, _VSTD::forward<_Args>(__args)...);
+}
+
+template <class _Tp>
+struct _LIBCPP_TYPE_VIS_ONLY hash<optional<_Tp> >
+{
+    typedef optional<_Tp> argument_type;
+    typedef size_t        result_type;
+
+    _LIBCPP_INLINE_VISIBILITY
+    result_type operator()(const argument_type& __opt) const _NOEXCEPT
+    {
+        return static_cast<bool>(__opt) ? hash<_Tp>()(*__opt) : 0;
+    }
+};
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif  // _LIBCPP_STD_VER > 14
+
+#endif  // _LIBCPP_OPTIONAL
Index: src/optional.cpp
===================================================================
--- src/optional.cpp
+++ src/optional.cpp
@@ -7,8 +7,24 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "optional"
 #include "experimental/optional"
 
+namespace std
+{
+
+#ifdef _LIBCPP_HAS_NO_DEFAULTED_FUNCTIONS
+
+bad_optional_access::~bad_optional_access() _NOEXCEPT {}
+
+#else
+
+bad_optional_access::~bad_optional_access() _NOEXCEPT = default;
+
+#endif
+
+} // std
+
 _LIBCPP_BEGIN_NAMESPACE_EXPERIMENTAL
 
 #ifdef _LIBCPP_HAS_NO_DEFAULTED_FUNCTIONS
Index: test/libcxx/utilities/optional/optional.object/optional.object.assign/copy.pass.cpp
===================================================================
--- /dev/null
+++ test/libcxx/utilities/optional/optional.object/optional.object.assign/copy.pass.cpp
@@ -0,0 +1,81 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// XFAIL: libcpp-no-exceptions
+// <optional>
+
+// optional<T>& operator=(const optional<T>& rhs);
+
+#include <optional>
+#include <string>
+#include <type_traits>
+
+using std::optional;
+
+struct X {};
+
+struct Y
+{
+    Y() = default;
+    Y& operator=(const Y&) { return *this; }
+};
+
+struct Z1
+{
+    Z1() = default;
+    Z1(Z1&&) = default;
+    Z1(const Z1&) = default;
+    Z1& operator=(Z1&&) = default;
+    Z1& operator=(const Z1&) = delete;
+};
+
+struct Z2
+{
+    Z2() = default;
+    Z2(Z2&&) = default;
+    Z2(const Z2&) = delete;
+    Z2& operator=(Z2&&) = default;
+    Z2& operator=(const Z2&) = default;
+};
+
+#if __cplusplus >= 201402
+template <class T>
+constexpr bool
+test()
+{
+    optional<T> opt;
+    optional<T> opt2;
+    opt = opt2;
+    return true;
+}
+#endif
+
+int main()
+{
+    {
+        using T = int;
+        static_assert((std::is_trivially_copy_assignable<optional<T>>::value), "");
+#if __cplusplus >= 201402
+        static_assert(test<T>(), "");
+#endif
+    }
+    {
+        using T = X;
+        static_assert((std::is_trivially_copy_assignable<optional<T>>::value), "");
+#if __cplusplus >= 201402
+        static_assert(test<T>(), "");
+#endif
+    }
+    static_assert(!(std::is_trivially_copy_assignable<optional<Y>>::value), "");
+    static_assert(!(std::is_trivially_copy_assignable<optional<std::string>>::value), "");
+
+    static_assert(!(std::is_copy_assignable<optional<Z1>>::value), "");
+    static_assert(!(std::is_copy_assignable<optional<Z2>>::value), "");
+}
Index: test/libcxx/utilities/optional/optional.object/optional.object.assign/move.pass.cpp
===================================================================
--- /dev/null
+++ test/libcxx/utilities/optional/optional.object/optional.object.assign/move.pass.cpp
@@ -0,0 +1,78 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// XFAIL: libcpp-no-exceptions
+// <optional>
+
+// optional<T>& operator=(optional<T>&& rhs);
+
+#include <optional>
+#include <string>
+#include <type_traits>
+#include <utility>
+
+using std::optional;
+
+struct X {};
+
+struct Y
+{
+    Y() = default;
+    Y& operator=(Y&&) { return *this; }
+};
+
+struct Z1
+{
+    Z1() = default;
+    Z1(Z1&&) = default;
+    Z1& operator=(Z1&&) = delete;
+};
+
+struct Z2
+{
+    Z2() = default;
+    Z2(Z2&&) = delete;
+    Z2& operator=(Z2&&) = default;
+};
+
+#if __cplusplus >= 201402
+template <class T>
+constexpr bool
+test()
+{
+    optional<T> opt;
+    optional<T> opt2;
+    opt = std::move(opt2);
+    return true;
+}
+#endif
+
+int main()
+{
+    {
+        using T = int;
+        static_assert((std::is_trivially_copy_constructible<optional<T>>::value), "");
+#if __cplusplus >= 201402
+        static_assert(test<T>(), "");
+#endif
+    }
+    {
+        using T = X;
+        static_assert((std::is_trivially_copy_constructible<optional<T>>::value), "");
+#if __cplusplus >= 201402
+        static_assert(test<T>(), "");
+#endif
+    }
+    static_assert(!(std::is_trivially_move_assignable<optional<Y>>::value), "");
+    static_assert(!(std::is_trivially_move_assignable<optional<std::string>>::value), "");
+
+    static_assert(!(std::is_move_assignable<optional<Z1>>::value), "");
+    static_assert(!(std::is_move_assignable<optional<Z2>>::value), "");
+}
Index: test/libcxx/utilities/optional/optional.object/optional.object.ctor/copy.pass.cpp
===================================================================
--- /dev/null
+++ test/libcxx/utilities/optional/optional.object/optional.object.ctor/copy.pass.cpp
@@ -0,0 +1,59 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// XFAIL: libcpp-no-exceptions
+// <optional>
+
+// optional(const optional<T>& rhs);
+
+#include <optional>
+#include <string>
+#include <type_traits>
+
+using std::optional;
+
+struct X {};
+
+struct Y
+{
+    Y() = default;
+    Y(const Y&) {}
+};
+
+struct Z
+{
+    Z() = default;
+    Z(Z&&) = delete;
+    Z(const Z&) = delete;
+    Z& operator=(Z&&) = delete;
+    Z& operator=(const Z&) = delete;
+};
+
+int main()
+{
+    {
+        using T = int;
+        static_assert((std::is_trivially_copy_constructible<optional<T>>::value), "");
+        constexpr optional<T> opt;
+        constexpr optional<T> opt2 = opt;
+        (void)opt2;
+    }
+    {
+        using T = X;
+        static_assert((std::is_trivially_copy_constructible<optional<T>>::value), "");
+        constexpr optional<T> opt;
+        constexpr optional<T> opt2 = opt;
+        (void)opt2;
+    }
+    static_assert(!(std::is_trivially_copy_constructible<optional<Y>>::value), "");
+    static_assert(!(std::is_trivially_copy_constructible<optional<std::string>>::value), "");
+
+    static_assert(!(std::is_copy_constructible<optional<Z>>::value), "");
+}
Index: test/libcxx/utilities/optional/optional.object/optional.object.ctor/move.pass.cpp
===================================================================
--- /dev/null
+++ test/libcxx/utilities/optional/optional.object/optional.object.ctor/move.pass.cpp
@@ -0,0 +1,60 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// XFAIL: libcpp-no-exceptions
+// <optional>
+
+// optional(optional<T>&& rhs);
+
+#include <optional>
+#include <string>
+#include <type_traits>
+#include <utility>
+
+using std::optional;
+
+struct X {};
+
+struct Y
+{
+    Y() = default;
+    Y(Y&&) {}
+};
+
+struct Z
+{
+    Z() = default;
+    Z(Z&&) = delete;
+    Z(const Z&) = delete;
+    Z& operator=(Z&&) = delete;
+    Z& operator=(const Z&) = delete;
+};
+
+int main()
+{
+    {
+        using T = int;
+        static_assert((std::is_trivially_copy_constructible<optional<T>>::value), "");
+        constexpr optional<T> opt;
+        constexpr optional<T> opt2 = std::move(opt);
+        (void)opt2;
+    }
+    {
+        using T = X;
+        static_assert((std::is_trivially_copy_constructible<optional<T>>::value), "");
+        constexpr optional<T> opt;
+        constexpr optional<T> opt2 = std::move(opt);
+        (void)opt2;
+    }
+    static_assert(!(std::is_trivially_move_constructible<optional<Y>>::value), "");
+    static_assert(!(std::is_trivially_move_constructible<optional<std::string>>::value), "");
+
+    static_assert(!(std::is_move_constructible<optional<Z>>::value), "");
+}
Index: test/libcxx/utilities/optional/optional.object/special_member_gen.pass.cpp
===================================================================
--- /dev/null
+++ test/libcxx/utilities/optional/optional.object/special_member_gen.pass.cpp
@@ -0,0 +1,66 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// <optional>
+
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+#include "archetypes.hpp"
+
+template <class T>
+struct SpecialMemberTest {
+    using O = std::optional<T>;
+
+    template <template <class> class TestMF>
+    static constexpr bool check_same() {
+        return TestMF<O>::value == TestMF<T>::value;
+    }
+
+    // Test that optional inherits the correct trivial/non-trivial members
+    static_assert(check_same<std::is_trivially_destructible>(), "");
+    static_assert(check_same<std::is_trivially_copyable>(), "");
+};
+
+template <class ...Args> static void sink(Args&&...) {}
+
+template <class ...TestTypes>
+struct DoTestsMetafunction {
+    DoTestsMetafunction() { sink(SpecialMemberTest<TestTypes>{}...); }
+};
+
+struct TrivialMoveNonTrivialCopy {
+    TrivialMoveNonTrivialCopy() = default;
+    TrivialMoveNonTrivialCopy(const TrivialMoveNonTrivialCopy&) {}
+    TrivialMoveNonTrivialCopy(TrivialMoveNonTrivialCopy&&) = default;
+    TrivialMoveNonTrivialCopy& operator=(const TrivialMoveNonTrivialCopy&) { return *this; }
+    TrivialMoveNonTrivialCopy& operator=(TrivialMoveNonTrivialCopy&&) = default;
+};
+
+struct TrivialCopyNonTrivialMove {
+    TrivialCopyNonTrivialMove() = default;
+    TrivialCopyNonTrivialMove(const TrivialCopyNonTrivialMove&) = default;
+    TrivialCopyNonTrivialMove(TrivialCopyNonTrivialMove&&) {}
+    TrivialCopyNonTrivialMove& operator=(const TrivialCopyNonTrivialMove&) = default;
+    TrivialCopyNonTrivialMove& operator=(TrivialCopyNonTrivialMove&&) { return *this; }
+};
+
+int main()
+{
+    sink(
+        ImplicitTypes::ApplyTypes<DoTestsMetafunction>{},
+        ExplicitTypes::ApplyTypes<DoTestsMetafunction>{},
+        NonLiteralTypes::ApplyTypes<DoTestsMetafunction>{},
+        NonTrivialTypes::ApplyTypes<DoTestsMetafunction>{},
+        DoTestsMetafunction<TrivialMoveNonTrivialCopy, TrivialCopyNonTrivialMove>{}
+    );
+}
Index: test/libcxx/utilities/optional/version.pass.cpp
===================================================================
--- /dev/null
+++ test/libcxx/utilities/optional/version.pass.cpp
@@ -0,0 +1,20 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <optional>
+
+#include <optional>
+
+#ifndef _LIBCPP_VERSION
+#error _LIBCPP_VERSION not defined
+#endif
+
+int main()
+{
+}
Index: test/std/utilities/meta/meta.unary/meta.unary.prop/is_nothrow_swappable_with.pass.cpp
===================================================================
--- test/std/utilities/meta/meta.unary/meta.unary.prop/is_nothrow_swappable_with.pass.cpp
+++ test/std/utilities/meta/meta.unary/meta.unary.prop/is_nothrow_swappable_with.pass.cpp
@@ -59,7 +59,7 @@
                       !std::is_nothrow_swappable_with<A&, A&>::value, "");
     }
     {
-        // test that hetrogenius swap is allowed only if both 'swap(A, B)' and
+        // test that heterogeneous swap is allowed only if both 'swap(A, B)' and
         // 'swap(B, A)' are valid.
         static_assert(std::is_nothrow_swappable_with<A&, B&>::value, "");
         static_assert(!std::is_nothrow_swappable_with<A&, C&>::value &&
Index: test/std/utilities/optional/optional.hash/hash.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.hash/hash.pass.cpp
@@ -0,0 +1,48 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// <optional>
+
+// template <class T> struct hash<optional<T>>;
+
+#include <optional>
+#include <string>
+#include <memory>
+#include <cassert>
+
+
+int main()
+{
+    using std::optional;
+    const std::size_t nullopt_hash =
+        std::hash<optional<double>>{}(optional<double>{});
+
+    {
+        typedef int T;
+        optional<T> opt;
+        assert(std::hash<optional<T>>{}(opt) == nullopt_hash);
+        opt = 2;
+        assert(std::hash<optional<T>>{}(opt) == std::hash<T>{}(*opt));
+    }
+    {
+        typedef std::string T;
+        optional<T> opt;
+        assert(std::hash<optional<T>>{}(opt) == nullopt_hash);
+        opt = std::string("123");
+        assert(std::hash<optional<T>>{}(opt) == std::hash<T>{}(*opt));
+    }
+    {
+        typedef std::unique_ptr<int> T;
+        optional<T> opt;
+        assert(std::hash<optional<T>>{}(opt) == nullopt_hash);
+        opt = std::unique_ptr<int>(new int(3));
+        assert(std::hash<optional<T>>{}(opt) == std::hash<T>{}(*opt));
+    }
+}
Index: test/std/utilities/optional/optional.bad_optional_access/default.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.bad_optional_access/default.pass.cpp
@@ -0,0 +1,23 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+
+// <optional>
+
+// class bad_optional_access is default constructible
+
+#include <optional>
+#include <type_traits>
+
+int main()
+{
+    using std::bad_optional_access;
+    bad_optional_access ex;
+}
Index: test/std/utilities/optional/optional.bad_optional_access/derive.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.bad_optional_access/derive.pass.cpp
@@ -0,0 +1,25 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+
+// <optional>
+
+// class bad_optional_access : public logic_error
+
+#include <optional>
+#include <type_traits>
+
+int main()
+{
+    using std::bad_optional_access;
+
+    static_assert(std::is_base_of<std::logic_error, bad_optional_access>::value, "");
+    static_assert(std::is_convertible<bad_optional_access*, std::logic_error*>::value, "");
+}
Index: test/std/utilities/optional/optional.comp_with_t/equal.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.comp_with_t/equal.pass.cpp
@@ -0,0 +1,53 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// <optional>
+
+// template <class T> constexpr bool operator==(const optional<T>& x, const T& v);
+// template <class T> constexpr bool operator==(const T& v, const optional<T>& x);
+
+#include <optional>
+
+using std::optional;
+
+struct X
+{
+    int i_;
+
+    constexpr X(int i) : i_(i) {}
+};
+
+constexpr bool operator == ( const X &lhs, const X &rhs )
+    { return lhs.i_ == rhs.i_ ; }
+
+int main()
+{
+    {
+    typedef X T;
+    typedef optional<T> O;
+
+    constexpr T val(2);
+    constexpr O o1;       // disengaged
+    constexpr O o2{1};    // engaged
+    constexpr O o3{val};  // engaged
+
+    static_assert ( !(o1 == T(1)), "" );
+    static_assert (  (o2 == T(1)), "" );
+    static_assert ( !(o3 == T(1)), "" );
+    static_assert (  (o3 == T(2)), "" );
+    static_assert (  (o3 == val),  "" );
+
+    static_assert ( !(T(1) == o1), "" );
+    static_assert (  (T(1) == o2), "" );
+    static_assert ( !(T(1) == o3), "" );
+    static_assert (  (T(2) == o3), "" );
+    static_assert (  (val  == o3), "" );
+    }
+}
Index: test/std/utilities/optional/optional.comp_with_t/greater.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.comp_with_t/greater.pass.cpp
@@ -0,0 +1,55 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// <optional>
+
+// template <class T> constexpr bool operator>(const optional<T>& x, const T& v);
+// template <class T> constexpr bool operator>(const T& v, const optional<T>& x);
+
+#include <optional>
+
+using std::optional;
+
+struct X
+{
+    int i_;
+
+    constexpr X(int i) : i_(i) {}
+};
+
+constexpr bool operator > ( const X &lhs, const X &rhs )
+    { return lhs.i_ > rhs.i_ ; }
+
+int main()
+{
+    {
+    typedef X T;
+    typedef optional<T> O;
+
+    constexpr T val(2);
+    constexpr O o1;       // disengaged
+    constexpr O o2{1};    // engaged
+    constexpr O o3{val};  // engaged
+
+    static_assert ( !(o1 > T(1)), "" );
+    static_assert ( !(o2 > T(1)), "" );  // equal
+    static_assert (  (o3 > T(1)), "" );
+    static_assert ( !(o2 >  val), "" );
+    static_assert ( !(o3 >  val), "" );  // equal
+    static_assert ( !(o3 > T(3)), "" );
+
+    static_assert (   (T(1) > o1), "" );
+    static_assert (  !(T(1) > o2), "" ); // equal
+    static_assert (  !(T(1) > o3), "" );
+    static_assert (   (val  > o2), "" );
+    static_assert (  !(val  > o3), "" ); // equal
+    static_assert (   (T(3) > o3), "" );
+    }
+}
Index: test/std/utilities/optional/optional.comp_with_t/greater_equal.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.comp_with_t/greater_equal.pass.cpp
@@ -0,0 +1,55 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// <optional>
+
+// template <class T> constexpr bool operator>=(const optional<T>& x, const T& v);
+// template <class T> constexpr bool operator>=(const T& v, const optional<T>& x);
+
+#include <optional>
+
+using std::optional;
+
+struct X
+{
+    int i_;
+
+    constexpr X(int i) : i_(i) {}
+};
+
+constexpr bool operator >= ( const X &lhs, const X &rhs )
+    { return lhs.i_ >= rhs.i_ ; }
+
+int main()
+{
+    {
+    typedef X T;
+    typedef optional<T> O;
+
+    constexpr T val(2);
+    constexpr O o1;       // disengaged
+    constexpr O o2{1};    // engaged
+    constexpr O o3{val};  // engaged
+
+    static_assert ( !(o1 >= T(1)), "" );
+    static_assert (  (o2 >= T(1)), "" );  // equal
+    static_assert (  (o3 >= T(1)), "" );
+    static_assert ( !(o2 >=  val), "" );
+    static_assert (  (o3 >=  val), "" );  // equal
+    static_assert ( !(o3 >= T(3)), "" );
+
+    static_assert (   (T(1) >= o1), "" );
+    static_assert (   (T(1) >= o2), "" ); // equal
+    static_assert (  !(T(1) >= o3), "" );
+    static_assert (   (val  >= o2), "" );
+    static_assert (   (val  >= o3), "" ); // equal
+    static_assert (   (T(3) >= o3), "" );
+    }
+}
Index: test/std/utilities/optional/optional.comp_with_t/less_equal.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.comp_with_t/less_equal.pass.cpp
@@ -0,0 +1,55 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// <optional>
+
+// template <class T> constexpr bool operator<=(const optional<T>& x, const T& v);
+// template <class T> constexpr bool operator<=(const T& v, const optional<T>& x);
+
+#include <optional>
+
+using std::optional;
+
+struct X
+{
+    int i_;
+
+    constexpr X(int i) : i_(i) {}
+};
+
+constexpr bool operator <= ( const X &lhs, const X &rhs )
+    { return lhs.i_ <= rhs.i_ ; }
+
+int main()
+{
+    {
+    typedef X T;
+    typedef optional<T> O;
+
+    constexpr T val(2);
+    constexpr O o1;       // disengaged
+    constexpr O o2{1};    // engaged
+    constexpr O o3{val};  // engaged
+
+    static_assert (  (o1 <= T(1)), "" );
+    static_assert (  (o2 <= T(1)), "" );  // equal
+    static_assert ( !(o3 <= T(1)), "" );
+    static_assert (  (o2 <=  val), "" );
+    static_assert (  (o3 <=  val), "" );  // equal
+    static_assert (  (o3 <= T(3)), "" );
+
+    static_assert (  !(T(1) <= o1), "" );
+    static_assert (   (T(1) <= o2), "" ); // equal
+    static_assert (   (T(1) <= o3), "" );
+    static_assert (  !(val  <= o2), "" );
+    static_assert (   (val  <= o3), "" ); // equal
+    static_assert (  !(T(3) <= o3), "" );
+    }
+}
Index: test/std/utilities/optional/optional.comp_with_t/less_than.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.comp_with_t/less_than.pass.cpp
@@ -0,0 +1,55 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// <optional>
+
+// template <class T> constexpr bool operator<(const optional<T>& x, const T& v);
+// template <class T> constexpr bool operator<(const T& v, const optional<T>& x);
+
+#include <optional>
+
+using std::optional;
+
+struct X
+{
+    int i_;
+
+    constexpr X(int i) : i_(i) {}
+};
+
+constexpr bool operator < ( const X &lhs, const X &rhs )
+    { return lhs.i_ < rhs.i_ ; }
+
+int main()
+{
+    {
+    typedef X T;
+    typedef optional<T> O;
+
+    constexpr T val(2);
+    constexpr O o1;       // disengaged
+    constexpr O o2{1};    // engaged
+    constexpr O o3{val};  // engaged
+
+    static_assert (  (o1 < T(1)), "" );
+    static_assert ( !(o2 < T(1)), "" );  // equal
+    static_assert ( !(o3 < T(1)), "" );
+    static_assert (  (o2 <  val), "" );
+    static_assert ( !(o3 <  val), "" );  // equal
+    static_assert (  (o3 < T(3)), "" );
+
+    static_assert (  !(T(1) < o1), "" );
+    static_assert (  !(T(1) < o2), "" ); // equal
+    static_assert (   (T(1) < o3), "" );
+    static_assert (  !(val  < o2), "" );
+    static_assert (  !(val  < o3), "" ); // equal
+    static_assert (  !(T(3) < o3), "" );
+    }
+}
Index: test/std/utilities/optional/optional.comp_with_t/not_equal.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.comp_with_t/not_equal.pass.cpp
@@ -0,0 +1,53 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// <optional>
+
+// template <class T> constexpr bool operator!=(const optional<T>& x, const T& v);
+// template <class T> constexpr bool operator!=(const T& v, const optional<T>& x);
+
+#include <optional>
+
+using std::optional;
+
+struct X
+{
+    int i_;
+
+    constexpr X(int i) : i_(i) {}
+};
+
+constexpr bool operator != ( const X &lhs, const X &rhs )
+    { return lhs.i_ != rhs.i_ ; }
+
+int main()
+{
+    {
+    typedef X T;
+    typedef optional<T> O;
+
+    constexpr T val(2);
+    constexpr O o1;       // disengaged
+    constexpr O o2{1};    // engaged
+    constexpr O o3{val};  // engaged
+
+    static_assert (  (o1 != T(1)), "" );
+    static_assert ( !(o2 != T(1)), "" );
+    static_assert (  (o3 != T(1)), "" );
+    static_assert ( !(o3 != T(2)), "" );
+    static_assert ( !(o3 != val),  "" );
+
+    static_assert (  (T(1) != o1), "" );
+    static_assert ( !(T(1) != o2), "" );
+    static_assert (  (T(1) != o3), "" );
+    static_assert ( !(T(2) != o3), "" );
+    static_assert ( !(val  != o3), "" );
+    }
+}
Index: test/std/utilities/optional/optional.nullops/equal.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.nullops/equal.pass.cpp
@@ -0,0 +1,39 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// <optional>
+
+// template <class T> constexpr bool operator==(const optional<T>& x, nullopt_t) noexcept;
+// template <class T> constexpr bool operator==(nullopt_t, const optional<T>& x) noexcept;
+
+#include <optional>
+
+int main()
+{
+    using std::optional;
+    using std::nullopt_t;
+    using std::nullopt;
+
+    {
+    typedef int T;
+    typedef optional<T> O;
+
+    constexpr O o1;     // disengaged
+    constexpr O o2{1};  // engaged
+
+    static_assert (  (nullopt == o1), "" );
+    static_assert ( !(nullopt == o2), "" );
+    static_assert (  (o1 == nullopt), "" );
+    static_assert ( !(o2 == nullopt), "" );
+
+    static_assert (noexcept(nullopt == o1), "");
+    static_assert (noexcept(o1 == nullopt), "");
+    }
+}
Index: test/std/utilities/optional/optional.nullops/greater.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.nullops/greater.pass.cpp
@@ -0,0 +1,39 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// <optional>
+
+// template <class T> constexpr bool operator>(const optional<T>& x, nullopt_t) noexcept;
+// template <class T> constexpr bool operator>(nullopt_t, const optional<T>& x) noexcept;
+
+#include <optional>
+
+int main()
+{
+    using std::optional;
+    using std::nullopt_t;
+    using std::nullopt;
+
+    {
+    typedef int T;
+    typedef optional<T> O;
+
+    constexpr O o1;     // disengaged
+    constexpr O o2{1};  // engaged
+
+    static_assert ( !(nullopt > o1), "" );
+    static_assert ( !(nullopt > o2), "" );
+    static_assert ( !(o1 > nullopt), "" );
+    static_assert (  (o2 > nullopt), "" );
+
+    static_assert (noexcept(nullopt > o1), "");
+    static_assert (noexcept(o1 > nullopt), "");
+    }
+}
Index: test/std/utilities/optional/optional.nullops/greater_equal.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.nullops/greater_equal.pass.cpp
@@ -0,0 +1,39 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// <optional>
+
+// template <class T> constexpr bool operator>=(const optional<T>& x, nullopt_t) noexcept;
+// template <class T> constexpr bool operator>=(nullopt_t, const optional<T>& x) noexcept;
+
+#include <optional>
+
+int main()
+{
+    using std::optional;
+    using std::nullopt_t;
+    using std::nullopt;
+
+    {
+    typedef int T;
+    typedef optional<T> O;
+
+    constexpr O o1;     // disengaged
+    constexpr O o2{1};  // engaged
+
+    static_assert (  (nullopt >= o1), "" );
+    static_assert ( !(nullopt >= o2), "" );
+    static_assert (  (o1 >= nullopt), "" );
+    static_assert (  (o2 >= nullopt), "" );
+
+    static_assert (noexcept(nullopt >= o1), "");
+    static_assert (noexcept(o1 >= nullopt), "");
+    }
+}
Index: test/std/utilities/optional/optional.nullops/less_equal.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.nullops/less_equal.pass.cpp
@@ -0,0 +1,41 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+
+// <optional>
+
+// template <class T> constexpr bool operator<=(const optional<T>& x, nullopt_t) noexcept;
+// template <class T> constexpr bool operator<=(nullopt_t, const optional<T>& x) noexcept;
+
+#include <optional>
+
+int main()
+{
+#if _LIBCPP_STD_VER > 11
+    using std::optional;
+    using std::nullopt_t;
+    using std::nullopt;
+
+    {
+    typedef int T;
+    typedef optional<T> O;
+
+    constexpr O o1;     // disengaged
+    constexpr O o2{1};  // engaged
+
+    static_assert (  (nullopt <= o1), "" );
+    static_assert (  (nullopt <= o2), "" );
+    static_assert (  (o1 <= nullopt), "" );
+    static_assert ( !(o2 <= nullopt), "" );
+
+    static_assert (noexcept(nullopt <= o1), "");
+    static_assert (noexcept(o1 <= nullopt), "");
+    }
+#endif
+}
Index: test/std/utilities/optional/optional.nullops/less_than.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.nullops/less_than.pass.cpp
@@ -0,0 +1,39 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// <optional>
+
+// template <class T> constexpr bool operator<(const optional<T>& x, nullopt_t) noexcept;
+// template <class T> constexpr bool operator<(nullopt_t, const optional<T>& x) noexcept;
+
+#include <optional>
+
+int main()
+{
+    using std::optional;
+    using std::nullopt_t;
+    using std::nullopt;
+
+    {
+    typedef int T;
+    typedef optional<T> O;
+
+    constexpr O o1;     // disengaged
+    constexpr O o2{1};  // engaged
+
+    static_assert ( !(nullopt < o1), "" );
+    static_assert (  (nullopt < o2), "" );
+    static_assert ( !(o1 < nullopt), "" );
+    static_assert ( !(o2 < nullopt), "" );
+
+    static_assert (noexcept(nullopt < o1), "");
+    static_assert (noexcept(o1 < nullopt), "");
+    }
+}
Index: test/std/utilities/optional/optional.nullops/not_equal.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.nullops/not_equal.pass.cpp
@@ -0,0 +1,39 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// <optional>
+
+// template <class T> constexpr bool operator!=(const optional<T>& x, nullopt_t) noexcept;
+// template <class T> constexpr bool operator!=(nullopt_t, const optional<T>& x) noexcept;
+
+#include <optional>
+
+int main()
+{
+    using std::optional;
+    using std::nullopt_t;
+    using std::nullopt;
+
+    {
+    typedef int T;
+    typedef optional<T> O;
+
+    constexpr O o1;     // disengaged
+    constexpr O o2{1};  // engaged
+
+    static_assert ( !(nullopt != o1), "" );
+    static_assert (  (nullopt != o2), "" );
+    static_assert ( !(o1 != nullopt), "" );
+    static_assert (  (o2 != nullopt), "" );
+
+    static_assert (noexcept(nullopt != o1), "");
+    static_assert (noexcept(o1 != nullopt), "");
+    }
+}
Index: test/std/utilities/optional/optional.nullopt/not_brace_initializable.fail.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.nullopt/not_brace_initializable.fail.cpp
@@ -0,0 +1,25 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// <optional>
+
+// struct nullopt_t{see below};
+
+#include <optional>
+
+using std::optional;
+using std::nullopt_t;
+
+int main()
+{
+    // I roughly interpret LWG2736 as "it shall not be possible to copy-list-initialize nullopt_t with an
+    // empty braced-init-list."
+    nullopt_t foo = {};
+}
Index: test/std/utilities/optional/optional.nullopt/nullopt_t.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.nullopt/nullopt_t.pass.cpp
@@ -0,0 +1,38 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// <optional>
+
+// struct nullopt_t{see below};
+// constexpr nullopt_t nullopt(unspecified);
+
+#include <optional>
+#include <type_traits>
+
+using std::optional;
+using std::nullopt_t;
+using std::nullopt;
+
+constexpr
+int
+test(const nullopt_t&)
+{
+    return 3;
+}
+
+int main()
+{
+    static_assert((std::is_class<nullopt_t>::value), "");
+    static_assert((std::is_empty<nullopt_t>::value), "");
+    static_assert((std::is_literal_type<nullopt_t>::value), "");
+    static_assert((!std::is_default_constructible<nullopt_t>::value), "");
+
+    static_assert(test(nullopt) == 3, "");
+}
Index: test/std/utilities/optional/optional.object/optional.object.assign/assign_value.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.object/optional.object.assign/assign_value.pass.cpp
@@ -0,0 +1,67 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// <optional>
+
+// template <class U> optional<T>& operator=(U&& v);
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+#include <memory>
+
+using std::optional;
+
+struct X
+{
+};
+
+int main()
+{
+    static_assert(std::is_assignable<optional<int>, int>::value, "");
+    static_assert(std::is_assignable<optional<int>, int&>::value, "");
+    static_assert(std::is_assignable<optional<int>&, int>::value, "");
+    static_assert(std::is_assignable<optional<int>&, int&>::value, "");
+    static_assert(std::is_assignable<optional<int>&, const int&>::value, "");
+    static_assert(!std::is_assignable<const optional<int>&, const int&>::value, "");
+    static_assert(!std::is_assignable<optional<int>, X>::value, "");
+    {
+        optional<int> opt;
+        opt = 1;
+        assert(static_cast<bool>(opt) == true);
+        assert(*opt == 1);
+    }
+    {
+        optional<int> opt;
+        const int i = 2;
+        opt = i;
+        assert(static_cast<bool>(opt) == true);
+        assert(*opt == i);
+    }
+    {
+        optional<int> opt(3);
+        const int i = 2;
+        opt = i;
+        assert(static_cast<bool>(opt) == true);
+        assert(*opt == i);
+    }
+    {
+        optional<std::unique_ptr<int>> opt;
+        opt = std::unique_ptr<int>(new int(3));
+        assert(static_cast<bool>(opt) == true);
+        assert(**opt == 3);
+    }
+    {
+        optional<std::unique_ptr<int>> opt(std::unique_ptr<int>(new int(2)));
+        opt = std::unique_ptr<int>(new int(3));
+        assert(static_cast<bool>(opt) == true);
+        assert(**opt == 3);
+    }
+}
Index: test/std/utilities/optional/optional.object/optional.object.assign/const_optional_U.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.object/optional.object.assign/const_optional_U.pass.cpp
@@ -0,0 +1,102 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// XFAIL: libcpp-no-exceptions
+// <optional>
+
+// From LWG2451:
+// template<class U>
+//   optional<T>& operator=(const optional<U>& rhs);
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+using std::optional;
+
+struct X
+{
+    static bool throw_now;
+
+    X() = default;
+    X(int)
+    {
+        if (throw_now)
+            throw 6;
+    }
+};
+
+bool X::throw_now = false;
+
+struct Y1
+{
+    Y1() = default;
+    Y1(const int&) {}
+    Y1& operator=(const Y1&) = delete;
+};
+
+struct Y2
+{
+    Y2() = default;
+    Y2(const int&) = delete;
+    Y2& operator=(const int&) { return *this; }
+};
+
+int main()
+{
+    {
+        optional<int> opt;
+        constexpr optional<short> opt2;
+        opt = opt2;
+        static_assert(static_cast<bool>(opt2) == false, "");
+        assert(static_cast<bool>(opt) == static_cast<bool>(opt2));
+    }
+    {
+        optional<int> opt;
+        constexpr optional<short> opt2(short{2});
+        opt = opt2;
+        static_assert(static_cast<bool>(opt2) == true, "");
+        static_assert(*opt2 == 2, "");
+        assert(static_cast<bool>(opt) == static_cast<bool>(opt2));
+        assert(*opt == *opt2);
+    }
+    {
+        optional<int> opt(3);
+        constexpr optional<short> opt2;
+        opt = opt2;
+        static_assert(static_cast<bool>(opt2) == false, "");
+        assert(static_cast<bool>(opt) == static_cast<bool>(opt2));
+    }
+    {
+        optional<int> opt(3);
+        constexpr optional<short> opt2(short{2});
+        opt = opt2;
+        static_assert(static_cast<bool>(opt2) == true, "");
+        static_assert(*opt2 == 2, "");
+        assert(static_cast<bool>(opt) == static_cast<bool>(opt2));
+        assert(*opt == *opt2);
+    }
+    {
+        optional<X> opt;
+        optional<int> opt2(42);
+        assert(static_cast<bool>(opt2) == true);
+        try
+        {
+            X::throw_now = true;
+            opt = opt2;
+            assert(false);
+        }
+        catch (int i)
+        {
+            assert(i == 6);
+            assert(static_cast<bool>(opt) == false);
+        }
+    }
+}
Index: test/std/utilities/optional/optional.object/optional.object.assign/copy.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.object/optional.object.assign/copy.pass.cpp
@@ -0,0 +1,86 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// XFAIL: libcpp-no-exceptions
+// <optional>
+
+// optional<T>& operator=(const optional<T>& rhs);
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+using std::optional;
+
+struct X
+{
+    static bool throw_now;
+
+    X() = default;
+    X(const X&)
+    {
+        if (throw_now)
+            throw 6;
+    }
+};
+
+bool X::throw_now = false;
+
+int main()
+{
+    {
+        optional<int> opt;
+        constexpr optional<int> opt2;
+        opt = opt2;
+        static_assert(static_cast<bool>(opt2) == false, "");
+        assert(static_cast<bool>(opt) == static_cast<bool>(opt2));
+    }
+    {
+        optional<int> opt;
+        constexpr optional<int> opt2(2);
+        opt = opt2;
+        static_assert(static_cast<bool>(opt2) == true, "");
+        static_assert(*opt2 == 2, "");
+        assert(static_cast<bool>(opt) == static_cast<bool>(opt2));
+        assert(*opt == *opt2);
+    }
+    {
+        optional<int> opt(3);
+        constexpr optional<int> opt2;
+        opt = opt2;
+        static_assert(static_cast<bool>(opt2) == false, "");
+        assert(static_cast<bool>(opt) == static_cast<bool>(opt2));
+    }
+    {
+        optional<int> opt(3);
+        constexpr optional<int> opt2(2);
+        opt = opt2;
+        static_assert(static_cast<bool>(opt2) == true, "");
+        static_assert(*opt2 == 2, "");
+        assert(static_cast<bool>(opt) == static_cast<bool>(opt2));
+        assert(*opt == *opt2);
+    }
+    {
+        optional<X> opt;
+        optional<X> opt2(X{});
+        assert(static_cast<bool>(opt2) == true);
+        try
+        {
+            X::throw_now = true;
+            opt = opt2;
+            assert(false);
+        }
+        catch (int i)
+        {
+            assert(i == 6);
+            assert(static_cast<bool>(opt) == false);
+        }
+    }
+}
Index: test/std/utilities/optional/optional.object/optional.object.assign/emplace.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.object/optional.object.assign/emplace.pass.cpp
@@ -0,0 +1,133 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// XFAIL: libcpp-no-exceptions
+// <optional>
+
+// template <class... Args> void optional<T>::emplace(Args&&... args);
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+#include <memory>
+
+using std::optional;
+
+class X
+{
+    int i_;
+    int j_ = 0;
+public:
+    X() : i_(0) {}
+    X(int i) : i_(i) {}
+    X(int i, int j) : i_(i), j_(j) {}
+
+    friend bool operator==(const X& x, const X& y)
+        {return x.i_ == y.i_ && x.j_ == y.j_;}
+};
+
+class Y
+{
+public:
+    static bool dtor_called;
+    Y() = default;
+    Y(int) {throw 6;}
+    ~Y() {dtor_called = true;}
+};
+
+bool Y::dtor_called = false;
+
+int main()
+{
+    {
+        optional<int> opt;
+        opt.emplace();
+        assert(static_cast<bool>(opt) == true);
+        assert(*opt == 0);
+    }
+    {
+        optional<int> opt;
+        opt.emplace(1);
+        assert(static_cast<bool>(opt) == true);
+        assert(*opt == 1);
+    }
+    {
+        optional<int> opt(2);
+        opt.emplace();
+        assert(static_cast<bool>(opt) == true);
+        assert(*opt == 0);
+    }
+    {
+        optional<int> opt(2);
+        opt.emplace(1);
+        assert(static_cast<bool>(opt) == true);
+        assert(*opt == 1);
+    }
+    {
+        optional<X> opt;
+        opt.emplace();
+        assert(static_cast<bool>(opt) == true);
+        assert(*opt == X());
+    }
+    {
+        optional<X> opt;
+        opt.emplace(1);
+        assert(static_cast<bool>(opt) == true);
+        assert(*opt == X(1));
+    }
+    {
+        optional<X> opt;
+        opt.emplace(1, 2);
+        assert(static_cast<bool>(opt) == true);
+        assert(*opt == X(1, 2));
+    }
+    {
+        optional<X> opt(X{3});
+        opt.emplace();
+        assert(static_cast<bool>(opt) == true);
+        assert(*opt == X());
+    }
+    {
+        optional<X> opt(X{3});
+        opt.emplace(1);
+        assert(static_cast<bool>(opt) == true);
+        assert(*opt == X(1));
+    }
+    {
+        optional<X> opt(X{3});
+        opt.emplace(1, 2);
+        assert(static_cast<bool>(opt) == true);
+        assert(*opt == X(1, 2));
+    }
+    {
+        Y y;
+        optional<Y> opt(y);
+        assert(Y::dtor_called == false);
+        opt.emplace();
+        assert(Y::dtor_called == true);
+    }
+    Y::dtor_called = false;
+    {
+        Y y;
+        optional<Y> opt(y);
+        try
+        {
+            assert(static_cast<bool>(opt) == true);
+            assert(Y::dtor_called == false);
+            opt.emplace(1);
+        }
+        catch (int i)
+        {
+            assert(i == 6);
+            assert(static_cast<bool>(opt) == false);
+            assert(Y::dtor_called == true);
+        }
+    }
+}
Index: test/std/utilities/optional/optional.object/optional.object.assign/emplace_initializer_list.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.object/optional.object.assign/emplace_initializer_list.pass.cpp
@@ -0,0 +1,110 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// XFAIL: libcpp-no-exceptions
+// <optional>
+
+// template <class U, class... Args>
+//   void optional<T>::emplace(initializer_list<U> il, Args&&... args);
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+#include <vector>
+
+using std::optional;
+
+class X
+{
+    int i_;
+    int j_ = 0;
+public:
+    static bool dtor_called;
+    constexpr X() : i_(0) {}
+    constexpr X(int i) : i_(i) {}
+    constexpr X(std::initializer_list<int> il) : i_(il.begin()[0]), j_(il.begin()[1]) {}
+    ~X() {dtor_called = true;}
+
+    friend constexpr bool operator==(const X& x, const X& y)
+        {return x.i_ == y.i_ && x.j_ == y.j_;}
+};
+
+bool X::dtor_called = false;
+
+class Y
+{
+    int i_;
+    int j_ = 0;
+public:
+    constexpr Y() : i_(0) {}
+    constexpr Y(int i) : i_(i) {}
+    constexpr Y(std::initializer_list<int> il) : i_(il.begin()[0]), j_(il.begin()[1]) {}
+
+    friend constexpr bool operator==(const Y& x, const Y& y)
+        {return x.i_ == y.i_ && x.j_ == y.j_;}
+};
+
+class Z
+{
+    int i_;
+    int j_ = 0;
+public:
+    static bool dtor_called;
+    Z() : i_(0) {}
+    Z(int i) : i_(i) {}
+    Z(std::initializer_list<int> il) : i_(il.begin()[0]), j_(il.begin()[1])
+        {throw 6;}
+    ~Z() {dtor_called = true;}
+
+    friend bool operator==(const Z& x, const Z& y)
+        {return x.i_ == y.i_ && x.j_ == y.j_;}
+};
+
+bool Z::dtor_called = false;
+
+int main()
+{
+    {
+        X x;
+        optional<X> opt(x);
+        assert(X::dtor_called == false);
+        opt.emplace({1, 2});
+        assert(X::dtor_called == true);
+        assert(*opt == X({1, 2}));
+    }
+    {
+        optional<std::vector<int>> opt;
+        opt.emplace({1, 2, 3}, std::allocator<int>());
+        assert(static_cast<bool>(opt) == true);
+        assert(*opt == std::vector<int>({1, 2, 3}));
+    }
+    {
+        optional<Y> opt;
+        opt.emplace({1, 2});
+        assert(static_cast<bool>(opt) == true);
+        assert(*opt == Y({1, 2}));
+    }
+    {
+        Z z;
+        optional<Z> opt(z);
+        try
+        {
+            assert(static_cast<bool>(opt) == true);
+            assert(Z::dtor_called == false);
+            opt.emplace({1, 2});
+        }
+        catch (int i)
+        {
+            assert(i == 6);
+            assert(static_cast<bool>(opt) == false);
+            assert(Z::dtor_called == true);
+        }
+    }
+}
Index: test/std/utilities/optional/optional.object/optional.object.assign/move.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.object/optional.object.assign/move.pass.cpp
@@ -0,0 +1,99 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// XFAIL: libcpp-no-exceptions
+// <optional>
+
+// optional<T>& operator=(optional<T>&& rhs)
+//     noexcept(is_nothrow_move_assignable<T>::value &&
+//              is_nothrow_move_constructible<T>::value);
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+using std::optional;
+
+struct X
+{
+    static bool throw_now;
+
+    X() = default;
+    X(X&&)
+    {
+        if (throw_now)
+            throw 6;
+    }
+    X& operator=(X&&) noexcept
+    {
+        return *this;
+    }
+};
+
+struct Y {};
+
+bool X::throw_now = false;
+
+int main()
+{
+    {
+        static_assert(std::is_nothrow_move_assignable<optional<int>>::value, "");
+        optional<int> opt;
+        constexpr optional<int> opt2;
+        opt = std::move(opt2);
+        static_assert(static_cast<bool>(opt2) == false, "");
+        assert(static_cast<bool>(opt) == static_cast<bool>(opt2));
+    }
+    {
+        optional<int> opt;
+        constexpr optional<int> opt2(2);
+        opt = std::move(opt2);
+        static_assert(static_cast<bool>(opt2) == true, "");
+        static_assert(*opt2 == 2, "");
+        assert(static_cast<bool>(opt) == static_cast<bool>(opt2));
+        assert(*opt == *opt2);
+    }
+    {
+        optional<int> opt(3);
+        constexpr optional<int> opt2;
+        opt = std::move(opt2);
+        static_assert(static_cast<bool>(opt2) == false, "");
+        assert(static_cast<bool>(opt) == static_cast<bool>(opt2));
+    }
+    {
+        optional<int> opt(3);
+        constexpr optional<int> opt2(2);
+        opt = std::move(opt2);
+        static_assert(static_cast<bool>(opt2) == true, "");
+        static_assert(*opt2 == 2, "");
+        assert(static_cast<bool>(opt) == static_cast<bool>(opt2));
+        assert(*opt == *opt2);
+    }
+    {
+        static_assert(!std::is_nothrow_move_assignable<optional<X>>::value, "");
+        optional<X> opt;
+        optional<X> opt2(X{});
+        assert(static_cast<bool>(opt2) == true);
+        try
+        {
+            X::throw_now = true;
+            opt = std::move(opt2);
+            assert(false);
+        }
+        catch (int i)
+        {
+            assert(i == 6);
+            assert(static_cast<bool>(opt) == false);
+        }
+    }
+    {
+        static_assert(std::is_nothrow_move_assignable<optional<Y>>::value, "");
+    }
+}
Index: test/std/utilities/optional/optional.object/optional.object.assign/nullopt_t.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.object/optional.object.assign/nullopt_t.pass.cpp
@@ -0,0 +1,61 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// <optional>
+
+// optional<T>& operator=(nullopt_t) noexcept;
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+using std::optional;
+using std::nullopt_t;
+using std::nullopt;
+
+struct X
+{
+    static bool dtor_called;
+    ~X() {dtor_called = true;}
+};
+
+bool X::dtor_called = false;
+
+int main()
+{
+    {
+        optional<int> opt;
+        static_assert(noexcept(opt = nullopt) == true, "");
+        opt = nullopt;
+        assert(static_cast<bool>(opt) == false);
+    }
+    {
+        optional<int> opt(3);
+        opt = nullopt;
+        assert(static_cast<bool>(opt) == false);
+    }
+    {
+        optional<X> opt;
+        static_assert(noexcept(opt = nullopt) == true, "");
+        assert(X::dtor_called == false);
+        opt = nullopt;
+        assert(X::dtor_called == false);
+        assert(static_cast<bool>(opt) == false);
+    }
+    assert(X::dtor_called == false); // TRANSITION, Clang/C2 VSO#239997
+    {
+        X x;
+        optional<X> opt(x);
+        assert(X::dtor_called == false);
+        opt = nullopt;
+        assert(X::dtor_called == true);
+        assert(static_cast<bool>(opt) == false);
+    }
+}
Index: test/std/utilities/optional/optional.object/optional.object.assign/optional_U.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.object/optional.object.assign/optional_U.pass.cpp
@@ -0,0 +1,102 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// XFAIL: libcpp-no-exceptions
+// <optional>
+
+// From LWG2451:
+// template <class U>
+// optional<T>& operator=(optional<U>&& rhs);
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+using std::optional;
+
+struct X
+{
+    static bool throw_now;
+
+    X() = default;
+    X(int &&)
+    {
+        if (throw_now)
+            throw 6;
+    }
+};
+
+bool X::throw_now = false;
+
+struct Y1
+{
+    Y1() = default;
+    Y1(const int&) {}
+    Y1& operator=(const Y1&) = delete;
+};
+
+struct Y2
+{
+    Y2() = default;
+    Y2(const int&) = delete;
+    Y2& operator=(const int&) { return *this; }
+};
+
+int main()
+{
+    {
+        optional<int> opt;
+        optional<short> opt2;
+        opt = std::move(opt2);
+        assert(static_cast<bool>(opt2) == false);
+        assert(static_cast<bool>(opt) == static_cast<bool>(opt2));
+    }
+    {
+        optional<int> opt;
+        optional<short> opt2(short{2});
+        opt = std::move(opt2);
+        assert(static_cast<bool>(opt2) == true);
+        assert(*opt2 == 2);
+        assert(static_cast<bool>(opt) == static_cast<bool>(opt2));
+        assert(*opt == *opt2);
+    }
+    {
+        optional<int> opt(3);
+        optional<short> opt2;
+        opt = std::move(opt2);
+        assert(static_cast<bool>(opt2) == false);
+        assert(static_cast<bool>(opt) == static_cast<bool>(opt2));
+    }
+    {
+        optional<int> opt(3);
+        optional<short> opt2(short{2});
+        opt = std::move(opt2);
+        assert(static_cast<bool>(opt2) == true);
+        assert(*opt2 == 2);
+        assert(static_cast<bool>(opt) == static_cast<bool>(opt2));
+        assert(*opt == *opt2);
+    }
+    {
+        optional<X> opt;
+        optional<int> opt2(42);
+        assert(static_cast<bool>(opt2) == true);
+        try
+        {
+            X::throw_now = true;
+            opt = std::move(opt2);
+            assert(false);
+        }
+        catch (int i)
+        {
+            assert(i == 6);
+            assert(static_cast<bool>(opt) == false);
+        }
+    }
+}
Index: test/std/utilities/optional/optional.object/optional.object.ctor/U.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.object/optional.object.ctor/U.pass.cpp
@@ -0,0 +1,114 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// XFAIL: libcpp-no-exceptions
+
+// <optional>
+
+// template <class U>
+//   constexpr optional(U&& u);
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+using std::optional;
+
+class X
+{
+    int i_;
+public:
+    X(int i) : i_(i) {}
+
+    friend bool operator==(const X& x, const X& y) {return x.i_ == y.i_;}
+};
+
+class Y
+{
+    int i_;
+public:
+    constexpr Y(int i) : i_(i) {}
+
+    friend constexpr bool operator==(const Y& x, const Y& y) {return x.i_ == y.i_;}
+};
+
+struct Z
+{
+    Z(int) {throw 6;}
+};
+
+template <class To, class From>
+constexpr bool implicit_conversion(optional<To>&& opt, const From& v)
+{
+    return opt && *opt == static_cast<To>(v);
+}
+
+int main()
+{
+    {
+        typedef int T;
+        typedef long long U;
+        constexpr T t(5);
+        static_assert(implicit_conversion<U>(t, t), "");
+
+        struct test_constexpr_ctor
+            : public optional<U>
+        {
+            constexpr test_constexpr_ctor(const T& t)
+                : optional<U>(t)
+            {}
+        };
+    }
+    {
+        typedef double T;
+        typedef long double U;
+        constexpr T t(3.14);
+        static_assert(implicit_conversion<U>(t, t), "");
+
+        struct test_constexpr_ctor
+            : public optional<U>
+        {
+            constexpr test_constexpr_ctor(const T& t)
+                : optional<U>(t)
+            {}
+        };
+    }
+    {
+        assert(implicit_conversion<X>(3, 3));
+    }
+    {
+        static_assert(implicit_conversion<Y>(3, 3), "");
+
+        struct test_constexpr_ctor
+            : public optional<Y>
+        {
+            constexpr test_constexpr_ctor(int i)
+                : optional<Y>(i)
+            {}
+        };
+
+    }
+    {
+        typedef Z T;
+        try
+        {
+            optional<T> opt = 3;
+            (void)opt;
+            assert(false);
+        }
+        catch (int i)
+        {
+            assert(i == 6);
+        }
+    }
+
+    static_assert(!(std::is_constructible<optional<X>, Y>::value), "");
+    static_assert(!(std::is_constructible<optional<X>, const Y&>::value), "");
+}
Index: test/std/utilities/optional/optional.object/optional.object.ctor/const_T.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.object/optional.object.ctor/const_T.pass.cpp
@@ -0,0 +1,113 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// XFAIL: libcpp-no-exceptions
+
+// <optional>
+
+// constexpr optional(const T& v);
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+using std::optional;
+
+class X
+{
+    int i_;
+public:
+    X(int i) : i_(i) {}
+
+    friend bool operator==(const X& x, const X& y) {return x.i_ == y.i_;}
+};
+
+class Y
+{
+    int i_;
+public:
+    constexpr Y(int i) : i_(i) {}
+
+    friend constexpr bool operator==(const Y& x, const Y& y) {return x.i_ == y.i_;}
+};
+
+class Z
+{
+public:
+    Z(int) {}
+    Z(const Z&) {throw 6;}
+};
+
+
+int main()
+{
+    {
+        typedef int T;
+        constexpr T t(5);
+        constexpr optional<T> opt(t);
+        static_assert(static_cast<bool>(opt) == true, "");
+        static_assert(*opt == 5, "");
+
+        struct test_constexpr_ctor
+            : public optional<T>
+        {
+            constexpr test_constexpr_ctor(const T&) {}
+        };
+
+    }
+    {
+        typedef double T;
+        constexpr T t(3);
+        constexpr optional<T> opt(t);
+        static_assert(static_cast<bool>(opt) == true, "");
+        static_assert(*opt == 3, "");
+
+        struct test_constexpr_ctor
+            : public optional<T>
+        {
+            constexpr test_constexpr_ctor(const T&) {}
+        };
+
+    }
+    {
+        typedef X T;
+        const T t(3);
+        optional<T> opt(t);
+        assert(static_cast<bool>(opt) == true);
+        assert(*opt == 3);
+    }
+    {
+        typedef Y T;
+        constexpr T t(3);
+        constexpr optional<T> opt(t);
+        static_assert(static_cast<bool>(opt) == true, "");
+        static_assert(*opt == 3, "");
+
+        struct test_constexpr_ctor
+            : public optional<T>
+        {
+            constexpr test_constexpr_ctor(const T&) {}
+        };
+
+    }
+    {
+        typedef Z T;
+        try
+        {
+            const T t(3);
+            optional<T> opt(t);
+            assert(false);
+        }
+        catch (int i)
+        {
+            assert(i == 6);
+        }
+    }
+}
Index: test/std/utilities/optional/optional.object/optional.object.ctor/const_optional_U.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.object/optional.object.ctor/const_optional_U.pass.cpp
@@ -0,0 +1,125 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// XFAIL: libcpp-no-exceptions
+// <optional>
+
+// template <class U>
+//   optional(const optional<U>& rhs);
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+using std::optional;
+
+template <class T, class U>
+void
+test(const optional<U>& rhs, bool is_going_to_throw = false)
+{
+    bool rhs_engaged = static_cast<bool>(rhs);
+    try
+    {
+        optional<T> lhs = rhs;
+        assert(is_going_to_throw == false);
+        assert(static_cast<bool>(lhs) == rhs_engaged);
+        if (rhs_engaged)
+            assert(*lhs == *rhs);
+    }
+    catch (int i)
+    {
+        assert(i == 6);
+    }
+}
+
+class X
+{
+    int i_;
+public:
+    X(int i) : i_(i) {}
+    X(const X& x) : i_(x.i_) {}
+    ~X() {i_ = 0;}
+    friend bool operator==(const X& x, const X& y) {return x.i_ == y.i_;}
+};
+
+class Y
+{
+    int i_;
+public:
+    Y(int i) : i_(i) {}
+
+    friend constexpr bool operator==(const Y& x, const Y& y) {return x.i_ == y.i_;}
+};
+
+int count = 0;
+
+class Z
+{
+    int i_;
+public:
+    Z(int i) : i_(i) {throw 6;}
+
+    friend constexpr bool operator==(const Z& x, const Z& y) {return x.i_ == y.i_;}
+};
+
+
+int main()
+{
+    {
+        typedef short U;
+        typedef int T;
+        optional<U> rhs;
+        test<T>(rhs);
+    }
+    {
+        typedef short U;
+        typedef int T;
+        optional<U> rhs(U{3});
+        test<T>(rhs);
+    }
+    {
+        typedef X T;
+        typedef int U;
+        optional<U> rhs;
+        test<T>(rhs);
+    }
+    {
+        typedef X T;
+        typedef int U;
+        optional<U> rhs(U{3});
+        test<T>(rhs);
+    }
+    {
+        typedef Y T;
+        typedef int U;
+        optional<U> rhs;
+        test<T>(rhs);
+    }
+    {
+        typedef Y T;
+        typedef int U;
+        optional<U> rhs(U{3});
+        test<T>(rhs);
+    }
+    {
+        typedef Z T;
+        typedef int U;
+        optional<U> rhs;
+        test<T>(rhs);
+    }
+    {
+        typedef Z T;
+        typedef int U;
+        optional<U> rhs(U{3});
+        test<T>(rhs, true);
+    }
+
+    static_assert(!(std::is_constructible<optional<X>, const optional<Y>&>::value), "");
+}
Index: test/std/utilities/optional/optional.object/optional.object.ctor/copy.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.object/optional.object.ctor/copy.pass.cpp
@@ -0,0 +1,120 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// XFAIL: libcpp-no-exceptions
+// <optional>
+
+// optional(const optional<T>& rhs);
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+using std::optional;
+
+template <class T>
+void
+test(const optional<T>& rhs, bool is_going_to_throw = false)
+{
+    bool rhs_engaged = static_cast<bool>(rhs);
+    try
+    {
+        optional<T> lhs = rhs;
+        assert(is_going_to_throw == false);
+        assert(static_cast<bool>(lhs) == rhs_engaged);
+        if (rhs_engaged)
+            assert(*lhs == *rhs);
+    }
+    catch (int i)
+    {
+        assert(i == 6);
+    }
+}
+
+class X
+{
+    int i_;
+public:
+    X(int i) : i_(i) {}
+    X(const X& x) : i_(x.i_) {}
+    ~X() {i_ = 0;}
+    friend bool operator==(const X& x, const X& y) {return x.i_ == y.i_;}
+};
+
+class Y
+{
+    int i_;
+public:
+    Y(int i) : i_(i) {}
+    Y(const Y& x) : i_(x.i_) {}
+
+    friend constexpr bool operator==(const Y& x, const Y& y) {return x.i_ == y.i_;}
+};
+
+int count = 0;
+
+class Z
+{
+    int i_;
+public:
+    Z(int i) : i_(i) {}
+    Z(const Z&)
+    {
+        if (++count == 2)
+            throw 6;
+    }
+
+    friend constexpr bool operator==(const Z& x, const Z& y) {return x.i_ == y.i_;}
+};
+
+
+int main()
+{
+    {
+        typedef int T;
+        optional<T> rhs;
+        test(rhs);
+    }
+    {
+        typedef int T;
+        optional<T> rhs(3);
+        test(rhs);
+    }
+    {
+        typedef X T;
+        optional<T> rhs;
+        test(rhs);
+    }
+    {
+        typedef X T;
+        optional<T> rhs(X(3));
+        test(rhs);
+    }
+    {
+        typedef Y T;
+        optional<T> rhs;
+        test(rhs);
+    }
+    {
+        typedef Y T;
+        optional<T> rhs(Y(3));
+        test(rhs);
+    }
+    {
+        typedef Z T;
+        optional<T> rhs;
+        test(rhs);
+    }
+    {
+        typedef Z T;
+        optional<T> rhs(Z(3));
+        test(rhs, true);
+    }
+}
Index: test/std/utilities/optional/optional.object/optional.object.ctor/default.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.object/optional.object.ctor/default.pass.cpp
@@ -0,0 +1,61 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// <optional>
+
+// constexpr optional() noexcept;
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+using std::optional;
+
+template <class Opt>
+void
+test_constexpr()
+{
+    static_assert(std::is_nothrow_default_constructible<Opt>::value, "");
+    constexpr Opt opt;
+    static_assert(static_cast<bool>(opt) == false, "");
+
+    struct test_constexpr_ctor
+        : public Opt
+    {
+        constexpr test_constexpr_ctor() {}
+    };
+}
+
+template <class Opt>
+void
+test()
+{
+    static_assert(std::is_nothrow_default_constructible<Opt>::value, "");
+    Opt opt;
+    assert(static_cast<bool>(opt) == false);
+
+    struct test_constexpr_ctor
+        : public Opt
+    {
+        constexpr test_constexpr_ctor() {}
+    };
+}
+
+struct X
+{
+    X();
+};
+
+int main()
+{
+    test_constexpr<optional<int>>();
+    test_constexpr<optional<int*>>();
+    test<optional<X>>();
+}
Index: test/std/utilities/optional/optional.object/optional.object.ctor/explicit_U.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.object/optional.object.ctor/explicit_U.pass.cpp
@@ -0,0 +1,87 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// XFAIL: libcpp-no-exceptions
+
+// <optional>
+
+// template <class U>
+//   explicit constexpr optional(U&& u);
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+using std::optional;
+
+class X
+{
+    int i_;
+public:
+    explicit X(int i) : i_(i) {}
+
+    friend bool operator==(const X& x, const X& y) {return x.i_ == y.i_;}
+};
+
+class Y
+{
+    int i_;
+public:
+    constexpr explicit Y(int i) : i_(i) {}
+
+    friend constexpr bool operator==(const Y& x, const Y& y) {return x.i_ == y.i_;}
+};
+
+class Z
+{
+public:
+    explicit Z(int) {throw 6;}
+};
+
+
+int main()
+{
+    {
+        typedef X T;
+        static_assert(!(std::is_convertible<int, optional<T>>::value), "");
+        optional<T> opt(3);
+        assert(static_cast<bool>(opt) == true);
+        assert(*opt == T(3));
+    }
+    {
+        typedef Y T;
+        static_assert(!(std::is_convertible<int, optional<T>>::value), "");
+        constexpr optional<T> opt(3);
+        static_assert(static_cast<bool>(opt) == true, "");
+        static_assert(*opt == T(3), "");
+
+        struct test_constexpr_ctor
+            : public optional<T>
+        {
+            constexpr test_constexpr_ctor(int i)
+                : optional<T>(i)
+            {}
+        };
+
+    }
+    {
+        typedef Z T;
+        static_assert(!(std::is_convertible<int, optional<T>>::value), "");
+        try
+        {
+            optional<T> opt(3);
+            assert(false);
+        }
+        catch (int i)
+        {
+            assert(i == 6);
+        }
+    }
+}
Index: test/std/utilities/optional/optional.object/optional.object.ctor/explicit_const_optional_U.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.object/optional.object.ctor/explicit_const_optional_U.pass.cpp
@@ -0,0 +1,112 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// XFAIL: libcpp-no-exceptions
+// <optional>
+
+// template <class U>
+//   explicit optional(const optional<U>& rhs);
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+using std::optional;
+
+template <class T, class U>
+void
+test(const optional<U>& rhs, bool is_going_to_throw = false)
+{
+    bool rhs_engaged = static_cast<bool>(rhs);
+    try
+    {
+        static_assert(!(std::is_convertible<const optional<U>&, optional<T>>::value), "");
+        optional<T> lhs(rhs);
+        assert(is_going_to_throw == false);
+        assert(static_cast<bool>(lhs) == rhs_engaged);
+        if (rhs_engaged)
+            assert(*lhs == T(*rhs));
+    }
+    catch (int i)
+    {
+        assert(i == 6);
+    }
+}
+
+class X
+{
+    int i_;
+public:
+    explicit X(int i) : i_(i) {}
+    X(const X& x) : i_(x.i_) {}
+    ~X() {i_ = 0;}
+    friend bool operator==(const X& x, const X& y) {return x.i_ == y.i_;}
+};
+
+class Y
+{
+    int i_;
+public:
+    explicit Y(int i) : i_(i) {}
+
+    friend constexpr bool operator==(const Y& x, const Y& y) {return x.i_ == y.i_;}
+};
+
+int count = 0;
+
+class Z
+{
+    int i_;
+public:
+    explicit Z(int i) : i_(i) {throw 6;}
+
+    friend constexpr bool operator==(const Z& x, const Z& y) {return x.i_ == y.i_;}
+};
+
+
+int main()
+{
+    {
+        typedef X T;
+        typedef int U;
+        optional<U> rhs;
+        test<T>(rhs);
+    }
+    {
+        typedef X T;
+        typedef int U;
+        optional<U> rhs(3);
+        test<T>(rhs);
+    }
+    {
+        typedef Y T;
+        typedef int U;
+        optional<U> rhs;
+        test<T>(rhs);
+    }
+    {
+        typedef Y T;
+        typedef int U;
+        optional<U> rhs(3);
+        test<T>(rhs);
+    }
+    {
+        typedef Z T;
+        typedef int U;
+        optional<U> rhs;
+        test<T>(rhs);
+    }
+    {
+        typedef Z T;
+        typedef int U;
+        optional<U> rhs(3);
+        test<T>(rhs, true);
+    }
+}
Index: test/std/utilities/optional/optional.object/optional.object.ctor/explicit_optional_U.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.object/optional.object.ctor/explicit_optional_U.pass.cpp
@@ -0,0 +1,77 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// XFAIL: libcpp-no-exceptions
+// <optional>
+
+// template <class U>
+//   explicit optional(optional<U>&& rhs);
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+using std::optional;
+
+template <class T, class U>
+void
+test(optional<U>&& rhs, bool is_going_to_throw = false)
+{
+    bool rhs_engaged = static_cast<bool>(rhs);
+    try
+    {
+        static_assert(!(std::is_convertible<optional<U>&&, optional<T>>::value), "");
+        optional<T> lhs(std::move(rhs));
+        assert(is_going_to_throw == false);
+        assert(static_cast<bool>(lhs) == rhs_engaged);
+    }
+    catch (int i)
+    {
+        assert(i == 6);
+    }
+}
+
+class X
+{
+    int i_;
+public:
+    explicit X(int i) : i_(i) {}
+    X(X&& x) : i_(std::exchange(x.i_, 0)) {}
+    ~X() {i_ = 0;}
+    friend bool operator==(const X& x, const X& y) {return x.i_ == y.i_;}
+};
+
+int count = 0;
+
+class Z
+{
+public:
+    explicit Z(int) { throw 6; }
+};
+
+int main()
+{
+    {
+        optional<int> rhs;
+        test<X>(std::move(rhs));
+    }
+    {
+        optional<int> rhs(3);
+        test<X>(std::move(rhs));
+    }
+    {
+        optional<int> rhs;
+        test<Z>(std::move(rhs));
+    }
+    {
+        optional<int> rhs(3);
+        test<Z>(std::move(rhs), true);
+    }
+}
Index: test/std/utilities/optional/optional.object/optional.object.ctor/in_place_t.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.object/optional.object.ctor/in_place_t.pass.cpp
@@ -0,0 +1,142 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// XFAIL: libcpp-no-exceptions
+
+// <optional>
+
+// template <class... Args>
+//   constexpr explicit optional(in_place_t, Args&&... args);
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+
+using std::optional;
+using std::in_place_t;
+using std::in_place;
+
+class X
+{
+    int i_;
+    int j_ = 0;
+public:
+    X() : i_(0) {}
+    X(int i) : i_(i) {}
+    X(int i, int j) : i_(i), j_(j) {}
+
+    ~X() {}
+
+    friend bool operator==(const X& x, const X& y)
+        {return x.i_ == y.i_ && x.j_ == y.j_;}
+};
+
+class Y
+{
+    int i_;
+    int j_ = 0;
+public:
+    constexpr Y() : i_(0) {}
+    constexpr Y(int i) : i_(i) {}
+    constexpr Y(int i, int j) : i_(i), j_(j) {}
+
+    friend constexpr bool operator==(const Y& x, const Y& y)
+        {return x.i_ == y.i_ && x.j_ == y.j_;}
+};
+
+class Z
+{
+public:
+    Z(int i) {throw 6;}
+};
+
+
+int main()
+{
+    {
+        constexpr optional<int> opt(in_place, 5);
+        static_assert(static_cast<bool>(opt) == true, "");
+        static_assert(*opt == 5, "");
+
+        struct test_constexpr_ctor
+            : public optional<int>
+        {
+            constexpr test_constexpr_ctor(in_place_t, int i)
+                : optional<int>(in_place, i) {}
+        };
+
+    }
+    {
+        const optional<X> opt(in_place);
+        assert(static_cast<bool>(opt) == true);
+        assert(*opt == X());
+    }
+    {
+        const optional<X> opt(in_place, 5);
+        assert(static_cast<bool>(opt) == true);
+        assert(*opt == X(5));
+    }
+    {
+        const optional<X> opt(in_place, 5, 4);
+        assert(static_cast<bool>(opt) == true);
+        assert(*opt == X(5, 4));
+    }
+    {
+        constexpr optional<Y> opt(in_place);
+        static_assert(static_cast<bool>(opt) == true, "");
+        static_assert(*opt == Y(), "");
+
+        struct test_constexpr_ctor
+            : public optional<Y>
+        {
+            constexpr test_constexpr_ctor(in_place_t)
+                : optional<Y>(in_place) {}
+        };
+
+    }
+    {
+        constexpr optional<Y> opt(in_place, 5);
+        static_assert(static_cast<bool>(opt) == true, "");
+        static_assert(*opt == Y(5), "");
+
+        struct test_constexpr_ctor
+            : public optional<Y>
+        {
+            constexpr test_constexpr_ctor(in_place_t, int i)
+                : optional<Y>(in_place, i) {}
+        };
+
+    }
+    {
+        constexpr optional<Y> opt(in_place, 5, 4);
+        static_assert(static_cast<bool>(opt) == true, "");
+        static_assert(*opt == Y(5, 4), "");
+
+        struct test_constexpr_ctor
+            : public optional<Y>
+        {
+            constexpr test_constexpr_ctor(in_place_t, int i, int j)
+                : optional<Y>(in_place, i, j) {}
+        };
+
+    }
+    {
+        try
+        {
+            const optional<Z> opt(in_place, 1);
+            assert(false);
+        }
+        catch (int i)
+        {
+            assert(i == 6);
+        }
+    }
+}
Index: test/std/utilities/optional/optional.object/optional.object.ctor/initializer_list.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.object/optional.object.ctor/initializer_list.pass.cpp
@@ -0,0 +1,113 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// XFAIL: libcpp-no-exceptions
+// <optional>
+
+// template <class U, class... Args>
+//     constexpr
+//     explicit optional(in_place_t, initializer_list<U> il, Args&&... args);
+
+#include <optional>
+#include <type_traits>
+#include <vector>
+#include <cassert>
+
+using std::optional;
+using std::in_place_t;
+using std::in_place;
+
+class X
+{
+    int i_;
+    int j_ = 0;
+public:
+    X() : i_(0) {}
+    X(int i) : i_(i) {}
+    X(int i, int j) : i_(i), j_(j) {}
+
+    ~X() {}
+
+    friend bool operator==(const X& x, const X& y)
+        {return x.i_ == y.i_ && x.j_ == y.j_;}
+};
+
+class Y
+{
+    int i_;
+    int j_ = 0;
+public:
+    constexpr Y() : i_(0) {}
+    constexpr Y(int i) : i_(i) {}
+    constexpr Y(std::initializer_list<int> il) : i_(il.begin()[0]), j_(il.begin()[1]) {}
+
+    friend constexpr bool operator==(const Y& x, const Y& y)
+        {return x.i_ == y.i_ && x.j_ == y.j_;}
+};
+
+class Z
+{
+    int i_;
+    int j_ = 0;
+public:
+    Z() : i_(0) {}
+    Z(int i) : i_(i) {}
+    Z(std::initializer_list<int> il) : i_(il.begin()[0]), j_(il.begin()[1])
+        {throw 6;}
+
+    friend bool operator==(const Z& x, const Z& y)
+        {return x.i_ == y.i_ && x.j_ == y.j_;}
+};
+
+int main()
+{
+    {
+        static_assert(!std::is_constructible<X, std::initializer_list<int>&>::value, "");
+        static_assert(!std::is_constructible<optional<X>, std::initializer_list<int>&>::value, "");
+    }
+    {
+        optional<std::vector<int>> opt(in_place, {3, 1});
+        assert(static_cast<bool>(opt) == true);
+        assert((*opt == std::vector<int>{3, 1}));
+        assert(opt->size() == 2);
+    }
+    {
+        optional<std::vector<int>> opt(in_place, {3, 1}, std::allocator<int>());
+        assert(static_cast<bool>(opt) == true);
+        assert((*opt == std::vector<int>{3, 1}));
+        assert(opt->size() == 2);
+    }
+    {
+        static_assert(std::is_constructible<optional<Y>, std::initializer_list<int>&>::value, "");
+        constexpr optional<Y> opt(in_place, {3, 1});
+        static_assert(static_cast<bool>(opt) == true, "");
+        static_assert(*opt == Y{3, 1}, "");
+
+        struct test_constexpr_ctor
+            : public optional<Y>
+        {
+            constexpr test_constexpr_ctor(in_place_t, std::initializer_list<int> i)
+                : optional<Y>(in_place, i) {}
+        };
+
+    }
+    {
+        static_assert(std::is_constructible<optional<Z>, std::initializer_list<int>&>::value, "");
+        try
+        {
+            optional<Z> opt(in_place, {3, 1});
+            assert(false);
+        }
+        catch (int i)
+        {
+            assert(i == 6);
+        }
+    }
+}
Index: test/std/utilities/optional/optional.object/optional.object.ctor/move.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.object/optional.object.ctor/move.pass.cpp
@@ -0,0 +1,119 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// XFAIL: libcpp-no-exceptions
+// <optional>
+
+// optional(optional<T>&& rhs) noexcept(is_nothrow_move_constructible<T>::value);
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+using std::optional;
+
+template <class T>
+void
+test(optional<T>& rhs, bool is_going_to_throw = false)
+{
+    static_assert(std::is_nothrow_move_constructible<optional<T>>::value ==
+                  std::is_nothrow_move_constructible<T>::value, "");
+    bool rhs_engaged = static_cast<bool>(rhs);
+    try
+    {
+        optional<T> lhs = std::move(rhs);
+        assert(is_going_to_throw == false);
+        assert(static_cast<bool>(lhs) == rhs_engaged);
+    }
+    catch (int i)
+    {
+        assert(i == 6);
+    }
+}
+
+class X
+{
+    int i_;
+public:
+    X(int i) : i_(i) {}
+    X(X&& x) : i_(x.i_) {x.i_ = 0;}
+    ~X() {i_ = 0;}
+    friend bool operator==(const X& x, const X& y) {return x.i_ == y.i_;}
+};
+
+class Y
+{
+    int i_;
+public:
+    Y(int i) : i_(i) {}
+    Y(Y&& x) noexcept : i_(x.i_) {x.i_ = 0;}
+
+    friend constexpr bool operator==(const Y& x, const Y& y) {return x.i_ == y.i_;}
+};
+
+int count = 0;
+
+class Z
+{
+    int i_;
+public:
+    Z(int i) : i_(i) {}
+    Z(Z&&)
+    {
+        if (++count == 2)
+            throw 6;
+    }
+
+    friend constexpr bool operator==(const Z& x, const Z& y) {return x.i_ == y.i_;}
+};
+
+int main()
+{
+    {
+        typedef int T;
+        optional<T> rhs;
+        test(rhs);
+    }
+    {
+        typedef int T;
+        optional<T> rhs(3);
+        test(rhs);
+    }
+    {
+        typedef X T;
+        optional<T> rhs;
+        test(rhs);
+    }
+    {
+        typedef X T;
+        optional<T> rhs(X(3));
+        test(rhs);
+    }
+    {
+        typedef Y T;
+        optional<T> rhs;
+        test(rhs);
+    }
+    {
+        typedef Y T;
+        optional<T> rhs(Y(3));
+        test(rhs);
+    }
+    {
+        typedef Z T;
+        optional<T> rhs;
+        test(rhs);
+    }
+    {
+        typedef Z T;
+        optional<T> rhs(Z(3));
+        test(rhs, true);
+    }
+}
Index: test/std/utilities/optional/optional.object/optional.object.ctor/nullopt_t.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.object/optional.object.ctor/nullopt_t.pass.cpp
@@ -0,0 +1,63 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// <optional>
+
+// constexpr optional(nullopt_t) noexcept;
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+using std::optional;
+using std::nullopt_t;
+using std::nullopt;
+
+template <class Opt>
+void
+test_constexpr()
+{
+    static_assert(noexcept(Opt(nullopt)), "");
+    constexpr Opt opt(nullopt);
+    static_assert(static_cast<bool>(opt) == false, "");
+
+    struct test_constexpr_ctor
+        : public Opt
+    {
+        constexpr test_constexpr_ctor() {}
+    };
+}
+
+template <class Opt>
+void
+test()
+{
+    static_assert(noexcept(Opt(nullopt)), "");
+    Opt opt(nullopt);
+    assert(static_cast<bool>(opt) == false);
+
+    struct test_constexpr_ctor
+        : public Opt
+    {
+        constexpr test_constexpr_ctor() {}
+    };
+}
+
+struct X
+{
+    X();
+};
+
+int main()
+{
+    test_constexpr<optional<int>>();
+    test_constexpr<optional<int*>>();
+    test<optional<X>>();
+}
Index: test/std/utilities/optional/optional.object/optional.object.ctor/optional_U.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.object/optional.object.ctor/optional_U.pass.cpp
@@ -0,0 +1,85 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// XFAIL: libcpp-no-exceptions
+// <optional>
+
+// template <class U>
+//   optional(optional<U>&& rhs);
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+using std::optional;
+
+template <class T, class U>
+void
+test(optional<U>&& rhs, bool is_going_to_throw = false)
+{
+    bool rhs_engaged = static_cast<bool>(rhs);
+    try
+    {
+        optional<T> lhs = std::move(rhs);
+        assert(is_going_to_throw == false);
+        assert(static_cast<bool>(lhs) == rhs_engaged);
+    }
+    catch (int i)
+    {
+        assert(i == 6);
+    }
+}
+
+class X
+{
+    int i_;
+public:
+    X(int i) : i_(i) {}
+    X(X&& x) : i_(std::exchange(x.i_, 0)) {}
+    ~X() {i_ = 0;}
+    friend bool operator==(const X& x, const X& y) {return x.i_ == y.i_;}
+};
+
+int count = 0;
+
+struct Z
+{
+    Z(int) { throw 6; }
+};
+
+int main()
+{
+    {
+        optional<short> rhs;
+        test<int>(std::move(rhs));
+    }
+    {
+        optional<short> rhs(short{3});
+        test<int>(std::move(rhs));
+    }
+    {
+        optional<int> rhs;
+        test<X>(std::move(rhs));
+    }
+    {
+        optional<int> rhs(3);
+        test<X>(std::move(rhs));
+    }
+    {
+        optional<int> rhs;
+        test<Z>(std::move(rhs));
+    }
+    {
+        optional<int> rhs(3);
+        test<Z>(std::move(rhs), true);
+    }
+
+    static_assert(!(std::is_constructible<optional<X>, optional<Z>>::value), "");
+}
Index: test/std/utilities/optional/optional.object/optional.object.ctor/rvalue_T.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.object/optional.object.ctor/rvalue_T.pass.cpp
@@ -0,0 +1,107 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// XFAIL: libcpp-no-exceptions
+
+// <optional>
+
+// constexpr optional(T&& v);
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+using std::optional;
+
+class X
+{
+    int i_;
+public:
+    X(int i) : i_(i) {}
+    X(X&& x) : i_(x.i_) {}
+
+    friend bool operator==(const X& x, const X& y) {return x.i_ == y.i_;}
+};
+
+class Y
+{
+    int i_;
+public:
+    constexpr Y(int i) : i_(i) {}
+    constexpr Y(Y&& x) : i_(x.i_) {}
+
+    friend constexpr bool operator==(const Y& x, const Y& y) {return x.i_ == y.i_;}
+};
+
+class Z
+{
+public:
+    Z(int) {}
+    Z(Z&&) {throw 6;}
+};
+
+
+int main()
+{
+    {
+        typedef int T;
+        constexpr optional<T> opt(T(5));
+        static_assert(static_cast<bool>(opt) == true, "");
+        static_assert(*opt == 5, "");
+
+        struct test_constexpr_ctor
+            : public optional<T>
+        {
+            constexpr test_constexpr_ctor(T&&) {}
+        };
+    }
+    {
+        typedef double T;
+        constexpr optional<T> opt(T(3));
+        static_assert(static_cast<bool>(opt) == true, "");
+        static_assert(*opt == 3, "");
+
+        struct test_constexpr_ctor
+            : public optional<T>
+        {
+            constexpr test_constexpr_ctor(T&&) {}
+        };
+    }
+    {
+        typedef X T;
+        optional<T> opt(T(3));
+        assert(static_cast<bool>(opt) == true);
+        assert(*opt == 3);
+    }
+    {
+        typedef Y T;
+        constexpr optional<T> opt(T(3));
+        static_assert(static_cast<bool>(opt) == true, "");
+        static_assert(*opt == 3, "");
+
+        struct test_constexpr_ctor
+            : public optional<T>
+        {
+            constexpr test_constexpr_ctor(T&&) {}
+        };
+    }
+    {
+        typedef Z T;
+        try
+        {
+            optional<T> opt(T(3));
+            assert(false);
+        }
+        catch (int i)
+        {
+            assert(i == 6);
+        }
+    }
+}
Index: test/std/utilities/optional/optional.object/optional.object.dtor/dtor.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.object/optional.object.dtor/dtor.pass.cpp
@@ -0,0 +1,54 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// <optional>
+
+// ~optional();
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+using std::optional;
+
+class X
+{
+public:
+    static bool dtor_called;
+    X() = default;
+    ~X() {dtor_called = true;}
+};
+
+bool X::dtor_called = false;
+
+int main()
+{
+    {
+        typedef int T;
+        static_assert(std::is_trivially_destructible<T>::value, "");
+        static_assert(std::is_trivially_destructible<optional<T>>::value, "");
+    }
+    {
+        typedef double T;
+        static_assert(std::is_trivially_destructible<T>::value, "");
+        static_assert(std::is_trivially_destructible<optional<T>>::value, "");
+    }
+    {
+        typedef X T;
+        static_assert(!std::is_trivially_destructible<T>::value, "");
+        static_assert(!std::is_trivially_destructible<optional<T>>::value, "");
+        {
+            X x;
+            optional<X> opt{x};
+            assert(X::dtor_called == false);
+        }
+        assert(X::dtor_called == true);
+    }
+}
Index: test/std/utilities/optional/optional.object/optional.object.mod/reset.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.object/optional.object.mod/reset.pass.cpp
@@ -0,0 +1,60 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+
+// <optional>
+
+// void reset() noexcept;
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+using std::optional;
+
+struct X
+{
+    static bool dtor_called;
+    ~X() {dtor_called = true;}
+};
+
+bool X::dtor_called = false;
+
+int main()
+{
+    {
+        optional<int> opt;
+        static_assert(noexcept(opt.reset()) == true, "");
+        opt.reset();
+        assert(static_cast<bool>(opt) == false);
+    }
+    {
+        optional<int> opt(3);
+        opt.reset();
+        assert(static_cast<bool>(opt) == false);
+    }
+    {
+        optional<X> opt;
+        static_assert(noexcept(opt.reset()) == true, "");
+        assert(X::dtor_called == false);
+        opt.reset();
+        assert(X::dtor_called == false);
+        assert(static_cast<bool>(opt) == false);
+    }
+    assert(X::dtor_called == false); // TRANSITION, Clang/C2 VSO#239997
+    {
+        X x;
+        optional<X> opt(x);
+        assert(X::dtor_called == false);
+        opt.reset();
+        assert(X::dtor_called == true);
+        assert(static_cast<bool>(opt) == false);
+    }
+}
Index: test/std/utilities/optional/optional.object/optional.object.observe/bool.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.object/optional.object.observe/bool.pass.cpp
@@ -0,0 +1,31 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// <optional>
+
+// constexpr explicit optional<T>::operator bool() const noexcept;
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+int main()
+{
+    using std::optional;
+
+    {
+        constexpr optional<int> opt;
+        static_assert(!opt, "");
+    }
+    {
+        constexpr optional<int> opt(0);
+        static_assert(opt, "");
+    }
+}
Index: test/std/utilities/optional/optional.object/optional.object.observe/dereference.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.object/optional.object.observe/dereference.pass.cpp
@@ -0,0 +1,63 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// <optional>
+
+// constexpr T& optional<T>::operator*() &;
+
+#ifdef _LIBCPP_DEBUG
+#define _LIBCPP_ASSERT(x, m) ((x) ? (void)0 : std::exit(0))
+#endif
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+using std::optional;
+
+struct X
+{
+    constexpr int test() const& {return 3;}
+    int test() & {return 4;}
+    constexpr int test() const&& {return 5;}
+    int test() && {return 6;}
+};
+
+#if __cplusplus >= 201402
+struct Y
+{
+    constexpr int test() {return 7;}
+};
+
+constexpr int
+test()
+{
+    optional<Y> opt{Y{}};
+    return (*opt).test();
+}
+#endif
+
+int main()
+{
+    {
+        optional<X> opt(X{});
+        assert((*opt).test() == 4);
+    }
+#if __cplusplus >= 201402
+    static_assert(test() == 7, "");
+#endif
+#ifdef _LIBCPP_DEBUG
+    {
+        optional<X> opt;
+        assert((*opt).test() == 3);
+        assert(false);
+    }
+#endif  // _LIBCPP_DEBUG
+}
Index: test/std/utilities/optional/optional.object/optional.object.observe/dereference_const.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.object/optional.object.observe/dereference_const.pass.cpp
@@ -0,0 +1,55 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// <optional>
+
+// constexpr const T& optional<T>::operator*() const &;
+
+#ifdef _LIBCPP_DEBUG
+#define _LIBCPP_ASSERT(x, m) ((x) ? (void)0 : std::exit(0))
+#endif
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+using std::optional;
+
+struct X
+{
+    constexpr int test() const& {return 3;}
+    int test() & {return 4;}
+    constexpr int test() const&& {return 5;}
+    int test() && {return 6;}
+};
+
+struct Y
+{
+    int test() const {return 2;}
+};
+
+int main()
+{
+    {
+        constexpr optional<X> opt(X{});
+        static_assert((*opt).test() == 3, "");
+    }
+    {
+        constexpr optional<Y> opt(Y{});
+        assert((*opt).test() == 2);
+    }
+#ifdef _LIBCPP_DEBUG
+    {
+        const optional<X> opt;
+        assert((*opt).test() == 3);
+        assert(false);
+    }
+#endif  // _LIBCPP_DEBUG
+}
Index: test/std/utilities/optional/optional.object/optional.object.observe/dereference_const_rvalue.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.object/optional.object.observe/dereference_const_rvalue.pass.cpp
@@ -0,0 +1,55 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// <optional>
+
+// constexpr T&& optional<T>::operator*() const &&;
+
+#ifdef _LIBCPP_DEBUG
+#define _LIBCPP_ASSERT(x, m) ((x) ? (void)0 : std::exit(0))
+#endif
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+using std::optional;
+
+struct X
+{
+    constexpr int test() const& {return 3;}
+    int test() & {return 4;}
+    constexpr int test() const&& {return 5;}
+    int test() && {return 6;}
+};
+
+struct Y
+{
+    int test() const && {return 2;}
+};
+
+int main()
+{
+    {
+        constexpr optional<X> opt(X{});
+        static_assert((*std::move(opt)).test() == 5, "");
+    }
+    {
+        constexpr optional<Y> opt(Y{});
+        assert((*std::move(opt)).test() == 2);
+    }
+#ifdef _LIBCPP_DEBUG
+    {
+        optional<X> opt;
+        assert((*std::move(opt)).test() == 5);
+        assert(false);
+    }
+#endif  // _LIBCPP_DEBUG
+}
Index: test/std/utilities/optional/optional.object/optional.object.observe/dereference_rvalue.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.object/optional.object.observe/dereference_rvalue.pass.cpp
@@ -0,0 +1,63 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// <optional>
+
+// constexpr T&& optional<T>::operator*() &&;
+
+#ifdef _LIBCPP_DEBUG
+#define _LIBCPP_ASSERT(x, m) ((x) ? (void)0 : std::exit(0))
+#endif
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+using std::optional;
+
+struct X
+{
+    constexpr int test() const& {return 3;}
+    int test() & {return 4;}
+    constexpr int test() const&& {return 5;}
+    int test() && {return 6;}
+};
+
+#if __cplusplus >= 201402
+struct Y
+{
+    constexpr int test() && {return 7;}
+};
+
+constexpr int
+test()
+{
+    optional<Y> opt{Y{}};
+    return (*std::move(opt)).test();
+}
+#endif
+
+int main()
+{
+    {
+        optional<X> opt(X{});
+        assert((*std::move(opt)).test() == 6);
+    }
+#if __cplusplus >= 201402
+    static_assert(test() == 7, "");
+#endif
+#ifdef _LIBCPP_DEBUG
+    {
+        optional<X> opt;
+        assert((*std::move(opt)).test() == 3);
+        assert(false);
+    }
+#endif  // _LIBCPP_DEBUG
+}
Index: test/std/utilities/optional/optional.object/optional.object.observe/has_value.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.object/optional.object.observe/has_value.pass.cpp
@@ -0,0 +1,31 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// <optional>
+
+// constexpr bool optional<T>::has_value() const noexcept;
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+int main()
+{
+    using std::optional;
+
+    {
+        constexpr optional<int> opt;
+        static_assert(!opt.has_value(), "");
+    }
+    {
+        constexpr optional<int> opt(0);
+        static_assert(opt.has_value(), "");
+    }
+}
Index: test/std/utilities/optional/optional.object/optional.object.observe/op_arrow.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.object/optional.object.observe/op_arrow.pass.cpp
@@ -0,0 +1,60 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// <optional>
+
+// constexpr T* optional<T>::operator->();
+
+#ifdef _LIBCPP_DEBUG
+#define _LIBCPP_ASSERT(x, m) ((x) ? (void)0 : std::exit(0))
+#endif
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+using std::optional;
+
+struct X
+{
+    int test() {return 3;}
+};
+
+#if __cplusplus >= 201402
+struct Y
+{
+    constexpr int test() {return 3;}
+};
+
+constexpr int
+test()
+{
+    optional<Y> opt{Y{}};
+    return opt->test();
+}
+#endif
+
+int main()
+{
+    {
+        optional<X> opt(X{});
+        assert(opt->test() == 3);
+    }
+#if __cplusplus >= 201402
+    static_assert(test() == 3, "");
+#endif
+#ifdef _LIBCPP_DEBUG
+    {
+        optional<X> opt;
+        assert(opt->test() == 3);
+        assert(false);
+    }
+#endif  // _LIBCPP_DEBUG
+}
Index: test/std/utilities/optional/optional.object/optional.object.observe/op_arrow_const.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.object/optional.object.observe/op_arrow_const.pass.cpp
@@ -0,0 +1,62 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// <optional>
+
+// constexpr const T* optional<T>::operator->() const;
+
+#ifdef _LIBCPP_DEBUG
+#define _LIBCPP_ASSERT(x, m) ((x) ? (void)0 : std::exit(0))
+#endif
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+using std::optional;
+
+struct X
+{
+    constexpr int test() const {return 3;}
+};
+
+struct Y
+{
+    int test() const {return 2;}
+};
+
+struct Z
+{
+    const Z* operator&() const;
+    constexpr int test() const {return 1;}
+};
+
+int main()
+{
+    {
+        constexpr optional<X> opt(X{});
+        static_assert(opt->test() == 3, "");
+    }
+    {
+        constexpr optional<Y> opt(Y{});
+        assert(opt->test() == 2);
+    }
+    {
+        constexpr optional<Z> opt(Z{});
+        static_assert(opt->test() == 1, "");
+    }
+#ifdef _LIBCPP_DEBUG
+    {
+        const optional<X> opt;
+        assert(opt->test() == 3);
+        assert(false);
+    }
+#endif  // _LIBCPP_DEBUG
+}
Index: test/std/utilities/optional/optional.object/optional.object.observe/value.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.object/optional.object.observe/value.pass.cpp
@@ -0,0 +1,68 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// XFAIL: libcpp-no-exceptions
+// <optional>
+
+// constexpr T& optional<T>::value() &;
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+using std::optional;
+using std::bad_optional_access;
+
+struct X
+{
+    X() = default;
+    X(const X&) = delete;
+    constexpr int test() const & {return 3;}
+    int test() & {return 4;}
+    constexpr int test() const && {return 5;}
+    int test() && {return 6;}
+};
+
+#if __cplusplus >= 201402
+struct Y
+{
+    constexpr int test() & {return 7;}
+};
+
+constexpr int
+test()
+{
+    optional<Y> opt{Y{}};
+    return opt.value().test();
+}
+#endif
+
+int main()
+{
+    {
+        optional<X> opt;
+        opt.emplace();
+        assert(opt.value().test() == 4);
+    }
+    {
+        optional<X> opt;
+        try
+        {
+            opt.value();
+            assert(false);
+        }
+        catch (const bad_optional_access&)
+        {
+        }
+    }
+#if __cplusplus >= 201402
+    static_assert(test() == 7, "");
+#endif
+}
Index: test/std/utilities/optional/optional.object/optional.object.observe/value_const.fail.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.object/optional.object.observe/value_const.fail.cpp
@@ -0,0 +1,33 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// <optional>
+
+// constexpr const T& optional<T>::value() const &;
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+using std::optional;
+
+struct X
+{
+    constexpr int test() const {return 3;}
+    int test() {return 4;}
+};
+
+int main()
+{
+    {
+        constexpr optional<X> opt;
+        static_assert(opt.value().test() == 3, "");
+    }
+}
Index: test/std/utilities/optional/optional.object/optional.object.observe/value_const.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.object/optional.object.observe/value_const.pass.cpp
@@ -0,0 +1,56 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// XFAIL: libcpp-no-exceptions
+// <optional>
+
+// constexpr const T& optional<T>::value() const &;
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+using std::optional;
+using std::in_place_t;
+using std::in_place;
+using std::bad_optional_access;
+
+struct X
+{
+    X() = default;
+    X(const X&) = delete;
+    constexpr int test() const & {return 3;}
+    int test() & {return 4;}
+    constexpr int test() const && {return 5;}
+    int test() && {return 6;}
+};
+
+int main()
+{
+    {
+        constexpr optional<X> opt(in_place);
+        static_assert(opt.value().test() == 3, "");
+    }
+    {
+        const optional<X> opt(in_place);
+        assert(opt.value().test() == 3);
+    }
+    {
+        const optional<X> opt;
+        try
+        {
+            opt.value();
+            assert(false);
+        }
+        catch (const bad_optional_access&)
+        {
+        }
+    }
+}
Index: test/std/utilities/optional/optional.object/optional.object.observe/value_const_rvalue.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.object/optional.object.observe/value_const_rvalue.pass.cpp
@@ -0,0 +1,56 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// XFAIL: libcpp-no-exceptions
+// <optional>
+
+// constexpr const T& optional<T>::value() const &&;
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+using std::optional;
+using std::in_place_t;
+using std::in_place;
+using std::bad_optional_access;
+
+struct X
+{
+    X() = default;
+    X(const X&) = delete;
+    constexpr int test() const & {return 3;}
+    int test() & {return 4;}
+    constexpr int test() const && {return 5;}
+    int test() && {return 6;}
+};
+
+int main()
+{
+    {
+        constexpr optional<X> opt(in_place);
+        static_assert(std::move(opt).value().test() == 5, "");
+    }
+    {
+        const optional<X> opt(in_place);
+        assert(std::move(opt).value().test() == 5);
+    }
+    {
+        const optional<X> opt;
+        try
+        {
+            std::move(opt).value();
+            assert(false);
+        }
+        catch (const bad_optional_access&)
+        {
+        }
+    }
+}
Index: test/std/utilities/optional/optional.object/optional.object.observe/value_or.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.object/optional.object.observe/value_or.pass.cpp
@@ -0,0 +1,66 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// <optional>
+
+// template <class U> T optional<T>::value_or(U&& v) &&;
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+using std::optional;
+using std::in_place_t;
+using std::in_place;
+
+struct Y
+{
+    int i_;
+
+    Y(int i) : i_(i) {}
+};
+
+struct X
+{
+    int i_;
+
+    X(int i) : i_(i) {}
+    X(X&& x) : i_(x.i_) {x.i_ = 0;}
+    X(const Y& y) : i_(y.i_) {}
+    X(Y&& y) : i_(y.i_+1) {}
+    friend constexpr bool operator==(const X& x, const X& y)
+        {return x.i_ == y.i_;}
+};
+
+int main()
+{
+    {
+        optional<X> opt(in_place, 2);
+        Y y(3);
+        assert(std::move(opt).value_or(y) == 2);
+        assert(*opt == 0);
+    }
+    {
+        optional<X> opt(in_place, 2);
+        assert(std::move(opt).value_or(Y(3)) == 2);
+        assert(*opt == 0);
+    }
+    {
+        optional<X> opt;
+        Y y(3);
+        assert(std::move(opt).value_or(y) == 3);
+        assert(!opt);
+    }
+    {
+        optional<X> opt;
+        assert(std::move(opt).value_or(Y(3)) == 4);
+        assert(!opt);
+    }
+}
Index: test/std/utilities/optional/optional.object/optional.object.observe/value_or_const.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.object/optional.object.observe/value_or_const.pass.cpp
@@ -0,0 +1,77 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// <optional>
+
+// template <class U> constexpr T optional<T>::value_or(U&& v) const&;
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+using std::optional;
+
+struct Y
+{
+    int i_;
+
+    constexpr Y(int i) : i_(i) {}
+};
+
+struct X
+{
+    int i_;
+
+    constexpr X(int i) : i_(i) {}
+    constexpr X(const Y& y) : i_(y.i_) {}
+    constexpr X(Y&& y) : i_(y.i_+1) {}
+    friend constexpr bool operator==(const X& x, const X& y)
+        {return x.i_ == y.i_;}
+};
+
+int main()
+{
+    {
+        constexpr optional<X> opt(2);
+        constexpr Y y(3);
+        static_assert(opt.value_or(y) == 2, "");
+    }
+    {
+        constexpr optional<X> opt(2);
+        static_assert(opt.value_or(Y(3)) == 2, "");
+    }
+    {
+        constexpr optional<X> opt;
+        constexpr Y y(3);
+        static_assert(opt.value_or(y) == 3, "");
+    }
+    {
+        constexpr optional<X> opt;
+        static_assert(opt.value_or(Y(3)) == 4, "");
+    }
+    {
+        const optional<X> opt(2);
+        const Y y(3);
+        assert(opt.value_or(y) == 2);
+    }
+    {
+        const optional<X> opt(2);
+        assert(opt.value_or(Y(3)) == 2);
+    }
+    {
+        const optional<X> opt;
+        const Y y(3);
+        assert(opt.value_or(y) == 3);
+    }
+    {
+        const optional<X> opt;
+        assert(opt.value_or(Y(3)) == 4);
+    }
+}
Index: test/std/utilities/optional/optional.object/optional.object.observe/value_rvalue.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.object/optional.object.observe/value_rvalue.pass.cpp
@@ -0,0 +1,68 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// XFAIL: libcpp-no-exceptions
+// <optional>
+
+// constexpr T& optional<T>::value() &&;
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+using std::optional;
+using std::bad_optional_access;
+
+struct X
+{
+    X() = default;
+    X(const X&) = delete;
+    constexpr int test() const & {return 3;}
+    int test() & {return 4;}
+    constexpr int test() const && {return 5;}
+    int test() && {return 6;}
+};
+
+#if __cplusplus >= 201402
+struct Y
+{
+    constexpr int test() && {return 7;}
+};
+
+constexpr int
+test()
+{
+    optional<Y> opt{Y{}};
+    return std::move(opt).value().test();
+}
+#endif
+
+int main()
+{
+    {
+        optional<X> opt;
+        opt.emplace();
+        assert(std::move(opt).value().test() == 6);
+    }
+    {
+        optional<X> opt;
+        try
+        {
+            std::move(opt).value();
+            assert(false);
+        }
+        catch (const bad_optional_access&)
+        {
+        }
+    }
+#if __cplusplus >= 201402
+    static_assert(test() == 7, "");
+#endif
+}
Index: test/std/utilities/optional/optional.object/optional.object.swap/swap.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.object/optional.object.swap/swap.pass.cpp
@@ -0,0 +1,301 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// XFAIL: libcpp-no-exceptions
+// <optional>
+
+// void swap(optional&)
+//     noexcept(is_nothrow_move_constructible<T>::value &&
+//              is_nothrow_swappable<T>::value)
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+using std::optional;
+
+class X
+{
+    int i_;
+public:
+    static unsigned dtor_called;
+    X(int i) : i_(i) {}
+    X(X&& x) = default;
+    X& operator=(X&&) = default;
+    ~X() {++dtor_called;}
+
+    friend bool operator==(const X& x, const X& y) {return x.i_ == y.i_;}
+};
+
+unsigned X::dtor_called = 0;
+
+class Y
+{
+    int i_;
+public:
+    static unsigned dtor_called;
+    Y(int i) : i_(i) {}
+    Y(Y&&) = default;
+    ~Y() {++dtor_called;}
+
+    friend constexpr bool operator==(const Y& x, const Y& y) {return x.i_ == y.i_;}
+    friend void swap(Y& x, Y& y) {std::swap(x.i_, y.i_);}
+};
+
+unsigned Y::dtor_called = 0;
+
+class Z
+{
+    int i_;
+public:
+    Z(int i) : i_(i) {}
+    Z(Z&&) {throw 7;}
+
+    friend constexpr bool operator==(const Z& x, const Z& y) {return x.i_ == y.i_;}
+    friend void swap(Z& x, Z& y) {throw 6;}
+};
+
+int main()
+{
+    {
+        optional<int> opt1;
+        optional<int> opt2;
+        static_assert(noexcept(opt1.swap(opt2)) == true, "");
+        assert(static_cast<bool>(opt1) == false);
+        assert(static_cast<bool>(opt2) == false);
+        opt1.swap(opt2);
+        assert(static_cast<bool>(opt1) == false);
+        assert(static_cast<bool>(opt2) == false);
+    }
+    {
+        optional<int> opt1(1);
+        optional<int> opt2;
+        static_assert(noexcept(opt1.swap(opt2)) == true, "");
+        assert(static_cast<bool>(opt1) == true);
+        assert(*opt1 == 1);
+        assert(static_cast<bool>(opt2) == false);
+        opt1.swap(opt2);
+        assert(static_cast<bool>(opt1) == false);
+        assert(static_cast<bool>(opt2) == true);
+        assert(*opt2 == 1);
+    }
+    {
+        optional<int> opt1;
+        optional<int> opt2(2);
+        static_assert(noexcept(opt1.swap(opt2)) == true, "");
+        assert(static_cast<bool>(opt1) == false);
+        assert(static_cast<bool>(opt2) == true);
+        assert(*opt2 == 2);
+        opt1.swap(opt2);
+        assert(static_cast<bool>(opt1) == true);
+        assert(*opt1 == 2);
+        assert(static_cast<bool>(opt2) == false);
+    }
+    {
+        optional<int> opt1(1);
+        optional<int> opt2(2);
+        static_assert(noexcept(opt1.swap(opt2)) == true, "");
+        assert(static_cast<bool>(opt1) == true);
+        assert(*opt1 == 1);
+        assert(static_cast<bool>(opt2) == true);
+        assert(*opt2 == 2);
+        opt1.swap(opt2);
+        assert(static_cast<bool>(opt1) == true);
+        assert(*opt1 == 2);
+        assert(static_cast<bool>(opt2) == true);
+        assert(*opt2 == 1);
+    }
+    {
+        optional<X> opt1;
+        optional<X> opt2;
+        static_assert(noexcept(opt1.swap(opt2)) == true, "");
+        assert(static_cast<bool>(opt1) == false);
+        assert(static_cast<bool>(opt2) == false);
+        opt1.swap(opt2);
+        assert(static_cast<bool>(opt1) == false);
+        assert(static_cast<bool>(opt2) == false);
+        assert(X::dtor_called == 0);
+    }
+    {
+        optional<X> opt1(1);
+        optional<X> opt2;
+        static_assert(noexcept(opt1.swap(opt2)) == true, "");
+        assert(static_cast<bool>(opt1) == true);
+        assert(*opt1 == 1);
+        assert(static_cast<bool>(opt2) == false);
+        X::dtor_called = 0;
+        opt1.swap(opt2);
+        assert(X::dtor_called == 1);
+        assert(static_cast<bool>(opt1) == false);
+        assert(static_cast<bool>(opt2) == true);
+        assert(*opt2 == 1);
+    }
+    {
+        optional<X> opt1;
+        optional<X> opt2(2);
+        static_assert(noexcept(opt1.swap(opt2)) == true, "");
+        assert(static_cast<bool>(opt1) == false);
+        assert(static_cast<bool>(opt2) == true);
+        assert(*opt2 == 2);
+        X::dtor_called = 0;
+        opt1.swap(opt2);
+        assert(X::dtor_called == 1);
+        assert(static_cast<bool>(opt1) == true);
+        assert(*opt1 == 2);
+        assert(static_cast<bool>(opt2) == false);
+    }
+    {
+        optional<X> opt1(1);
+        optional<X> opt2(2);
+        static_assert(noexcept(opt1.swap(opt2)) == true, "");
+        assert(static_cast<bool>(opt1) == true);
+        assert(*opt1 == 1);
+        assert(static_cast<bool>(opt2) == true);
+        assert(*opt2 == 2);
+        X::dtor_called = 0;
+        opt1.swap(opt2);
+        assert(X::dtor_called == 1);  // from inside std::swap
+        assert(static_cast<bool>(opt1) == true);
+        assert(*opt1 == 2);
+        assert(static_cast<bool>(opt2) == true);
+        assert(*opt2 == 1);
+    }
+    {
+        optional<Y> opt1;
+        optional<Y> opt2;
+        static_assert(noexcept(opt1.swap(opt2)) == false, "");
+        assert(static_cast<bool>(opt1) == false);
+        assert(static_cast<bool>(opt2) == false);
+        opt1.swap(opt2);
+        assert(static_cast<bool>(opt1) == false);
+        assert(static_cast<bool>(opt2) == false);
+        assert(Y::dtor_called == 0);
+    }
+    {
+        optional<Y> opt1(1);
+        optional<Y> opt2;
+        static_assert(noexcept(opt1.swap(opt2)) == false, "");
+        assert(static_cast<bool>(opt1) == true);
+        assert(*opt1 == 1);
+        assert(static_cast<bool>(opt2) == false);
+        Y::dtor_called = 0;
+        opt1.swap(opt2);
+        assert(Y::dtor_called == 1);
+        assert(static_cast<bool>(opt1) == false);
+        assert(static_cast<bool>(opt2) == true);
+        assert(*opt2 == 1);
+    }
+    {
+        optional<Y> opt1;
+        optional<Y> opt2(2);
+        static_assert(noexcept(opt1.swap(opt2)) == false, "");
+        assert(static_cast<bool>(opt1) == false);
+        assert(static_cast<bool>(opt2) == true);
+        assert(*opt2 == 2);
+        Y::dtor_called = 0;
+        opt1.swap(opt2);
+        assert(Y::dtor_called == 1);
+        assert(static_cast<bool>(opt1) == true);
+        assert(*opt1 == 2);
+        assert(static_cast<bool>(opt2) == false);
+    }
+    {
+        optional<Y> opt1(1);
+        optional<Y> opt2(2);
+        static_assert(noexcept(opt1.swap(opt2)) == false, "");
+        assert(static_cast<bool>(opt1) == true);
+        assert(*opt1 == 1);
+        assert(static_cast<bool>(opt2) == true);
+        assert(*opt2 == 2);
+        Y::dtor_called = 0;
+        opt1.swap(opt2);
+        assert(Y::dtor_called == 0);
+        assert(static_cast<bool>(opt1) == true);
+        assert(*opt1 == 2);
+        assert(static_cast<bool>(opt2) == true);
+        assert(*opt2 == 1);
+    }
+    {
+        optional<Z> opt1;
+        optional<Z> opt2;
+        static_assert(noexcept(opt1.swap(opt2)) == false, "");
+        assert(static_cast<bool>(opt1) == false);
+        assert(static_cast<bool>(opt2) == false);
+        opt1.swap(opt2);
+        assert(static_cast<bool>(opt1) == false);
+        assert(static_cast<bool>(opt2) == false);
+    }
+    {
+        optional<Z> opt1;
+        opt1.emplace(1);
+        optional<Z> opt2;
+        static_assert(noexcept(opt1.swap(opt2)) == false, "");
+        assert(static_cast<bool>(opt1) == true);
+        assert(*opt1 == 1);
+        assert(static_cast<bool>(opt2) == false);
+        try
+        {
+            opt1.swap(opt2);
+            assert(false);
+        }
+        catch (int i)
+        {
+            assert(i == 7);
+        }
+        assert(static_cast<bool>(opt1) == true);
+        assert(*opt1 == 1);
+        assert(static_cast<bool>(opt2) == false);
+    }
+    {
+        optional<Z> opt1;
+        optional<Z> opt2;
+        opt2.emplace(2);
+        static_assert(noexcept(opt1.swap(opt2)) == false, "");
+        assert(static_cast<bool>(opt1) == false);
+        assert(static_cast<bool>(opt2) == true);
+        assert(*opt2 == 2);
+        try
+        {
+            opt1.swap(opt2);
+            assert(false);
+        }
+        catch (int i)
+        {
+            assert(i == 7);
+        }
+        assert(static_cast<bool>(opt1) == false);
+        assert(static_cast<bool>(opt2) == true);
+        assert(*opt2 == 2);
+    }
+    {
+        optional<Z> opt1;
+        opt1.emplace(1);
+        optional<Z> opt2;
+        opt2.emplace(2);
+        static_assert(noexcept(opt1.swap(opt2)) == false, "");
+        assert(static_cast<bool>(opt1) == true);
+        assert(*opt1 == 1);
+        assert(static_cast<bool>(opt2) == true);
+        assert(*opt2 == 2);
+        try
+        {
+            opt1.swap(opt2);
+            assert(false);
+        }
+        catch (int i)
+        {
+            assert(i == 6);
+        }
+        assert(static_cast<bool>(opt1) == true);
+        assert(*opt1 == 1);
+        assert(static_cast<bool>(opt2) == true);
+        assert(*opt2 == 2);
+    }
+}
Index: test/std/utilities/optional/optional.object/optional_const_void.fail.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.object/optional_const_void.fail.cpp
@@ -0,0 +1,22 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// <optional>
+
+// T shall be an object type and shall satisfy the requirements of Destructible
+
+#include <optional>
+
+int main()
+{
+    using std::optional;
+
+    optional<const void> opt;
+}
Index: test/std/utilities/optional/optional.object/optional_not_destructible.fail.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.object/optional_not_destructible.fail.cpp
@@ -0,0 +1,28 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// <optional>
+
+// T shall be an object type and shall satisfy the requirements of Destructible
+
+#include <optional>
+
+using std::optional;
+
+struct X
+{
+private:
+    ~X() {}
+};
+
+int main()
+{
+    optional<X> opt;
+}
Index: test/std/utilities/optional/optional.object/optional_void.fail.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.object/optional_void.fail.cpp
@@ -0,0 +1,22 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// <optional>
+
+// T shall be an object type and shall satisfy the requirements of Destructible
+
+#include <optional>
+
+int main()
+{
+    using std::optional;
+
+    optional<void> opt;
+}
Index: test/std/utilities/optional/optional.object/special_member_gen.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.object/special_member_gen.pass.cpp
@@ -0,0 +1,74 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// <optional>
+
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+#include "archetypes.hpp"
+
+template <class T>
+struct SpecialMemberTest {
+    using O = std::optional<T>;
+
+    static_assert(std::is_default_constructible_v<O>,
+        "optional is always default constructible.");
+    static_assert(std::is_copy_constructible_v<O> == std::is_copy_constructible_v<T>,
+        "optional<T> is copy constructible if and only if T is copy constructible.");
+    static_assert(std::is_move_constructible_v<O> ==
+        (std::is_copy_constructible_v<T> || std::is_move_constructible_v<T>),
+        "optional<T> is move constructible if and only if T is copy or move constructible.");
+    static_assert(std::is_copy_assignable_v<O> ==
+        (std::is_copy_constructible_v<T> && std::is_copy_assignable_v<T>),
+        "optional<T> is copy assignable if and only if T is both copy "
+        "constructible and copy assignable.");
+    static_assert(std::is_move_assignable_v<O> ==
+        ((std::is_copy_constructible_v<T> && std::is_copy_assignable_v<T>) ||
+         (std::is_move_constructible_v<T> && std::is_move_assignable_v<T>)),
+        "optional<T> is move assignable if and only if T is both move assignable and "
+        "move constructible, or both copy constructible and copy assignable.");
+};
+
+template <class ...Args> static void sink(Args&&...) {}
+
+template <class ...TestTypes>
+struct DoTestsMetafunction {
+    DoTestsMetafunction() { sink(SpecialMemberTest<TestTypes>{}...); }
+};
+
+struct TrivialMoveNonTrivialCopy {
+    TrivialMoveNonTrivialCopy() = default;
+    TrivialMoveNonTrivialCopy(const TrivialMoveNonTrivialCopy&) {}
+    TrivialMoveNonTrivialCopy(TrivialMoveNonTrivialCopy&&) = default;
+    TrivialMoveNonTrivialCopy& operator=(const TrivialMoveNonTrivialCopy&) { return *this; }
+    TrivialMoveNonTrivialCopy& operator=(TrivialMoveNonTrivialCopy&&) = default;
+};
+
+struct TrivialCopyNonTrivialMove {
+    TrivialCopyNonTrivialMove() = default;
+    TrivialCopyNonTrivialMove(const TrivialCopyNonTrivialMove&) = default;
+    TrivialCopyNonTrivialMove(TrivialCopyNonTrivialMove&&) {}
+    TrivialCopyNonTrivialMove& operator=(const TrivialCopyNonTrivialMove&) = default;
+    TrivialCopyNonTrivialMove& operator=(TrivialCopyNonTrivialMove&&) { return *this; }
+};
+
+int main()
+{
+    sink(
+        ImplicitTypes::ApplyTypes<DoTestsMetafunction>{},
+        ExplicitTypes::ApplyTypes<DoTestsMetafunction>{},
+        NonLiteralTypes::ApplyTypes<DoTestsMetafunction>{},
+        NonTrivialTypes::ApplyTypes<DoTestsMetafunction>{},
+        DoTestsMetafunction<TrivialMoveNonTrivialCopy, TrivialCopyNonTrivialMove>{}
+    );
+}
Index: test/std/utilities/optional/optional.object/types.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.object/types.pass.cpp
@@ -0,0 +1,38 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// <optional>
+
+// template <class T>
+// class optional
+// {
+// public:
+//     typedef T value_type;
+//     ...
+
+#include <optional>
+#include <type_traits>
+
+using std::optional;
+
+template <class Opt, class T>
+void
+test()
+{
+    static_assert(std::is_same<typename Opt::value_type, T>::value, "");
+}
+
+int main()
+{
+    test<optional<int>, int>();
+    test<optional<const int>, const int>();
+    test<optional<double>, double>();
+    test<optional<const double>, const double>();
+}
Index: test/std/utilities/optional/optional.relops/equal.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.relops/equal.pass.cpp
@@ -0,0 +1,74 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// <optional>
+
+// template <class T> constexpr bool operator==(const optional<T>& x, const optional<T>& y);
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+using std::optional;
+
+struct X
+{
+    int i_;
+
+    constexpr X(int i) : i_(i) {}
+};
+
+constexpr bool operator == ( const X &lhs, const X &rhs )
+    { return lhs.i_ == rhs.i_ ; }
+
+int main()
+{
+    {
+    typedef X T;
+    typedef optional<T> O;
+
+    constexpr O o1;     // disengaged
+    constexpr O o2;     // disengaged
+    constexpr O o3{1};  // engaged
+    constexpr O o4{2};  // engaged
+    constexpr O o5{1};  // engaged
+
+    static_assert (   o1 == o1 , "" );
+    static_assert (   o1 == o2 , "" );
+    static_assert ( !(o1 == o3), "" );
+    static_assert ( !(o1 == o4), "" );
+    static_assert ( !(o1 == o5), "" );
+
+    static_assert (   o2 == o1 , "" );
+    static_assert (   o2 == o2 , "" );
+    static_assert ( !(o2 == o3), "" );
+    static_assert ( !(o2 == o4), "" );
+    static_assert ( !(o2 == o5), "" );
+
+    static_assert ( !(o3 == o1), "" );
+    static_assert ( !(o3 == o2), "" );
+    static_assert (   o3 == o3 , "" );
+    static_assert ( !(o3 == o4), "" );
+    static_assert (   o3 == o5 , "" );
+
+    static_assert ( !(o4 == o1), "" );
+    static_assert ( !(o4 == o2), "" );
+    static_assert ( !(o4 == o3), "" );
+    static_assert (   o4 == o4 , "" );
+    static_assert ( !(o4 == o5), "" );
+
+    static_assert ( !(o5 == o1), "" );
+    static_assert ( !(o5 == o2), "" );
+    static_assert (   o5 == o3 , "" );
+    static_assert ( !(o5 == o4), "" );
+    static_assert (   o5 == o5 , "" );
+
+    }
+}
Index: test/std/utilities/optional/optional.relops/greater_equal.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.relops/greater_equal.pass.cpp
@@ -0,0 +1,70 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// <optional>
+
+// template <class T> constexpr bool operator>= (const optional<T>& x, const optional<T>& y);
+
+#include <optional>
+
+using std::optional;
+
+struct X
+{
+    int i_;
+
+    constexpr X(int i) : i_(i) {}
+};
+
+constexpr bool operator >= ( const X &lhs, const X &rhs )
+    { return lhs.i_ >= rhs.i_ ; }
+
+int main()
+{
+    {
+    typedef optional<X> O;
+
+    constexpr O o1;     // disengaged
+    constexpr O o2;     // disengaged
+    constexpr O o3{1};  // engaged
+    constexpr O o4{2};  // engaged
+    constexpr O o5{1};  // engaged
+
+    static_assert (  (o1 >= o1), "" );
+    static_assert (  (o1 >= o2), "" );
+    static_assert ( !(o1 >= o3), "" );
+    static_assert ( !(o1 >= o4), "" );
+    static_assert ( !(o1 >= o5), "" );
+
+    static_assert (  (o2 >= o1), "" );
+    static_assert (  (o2 >= o2), "" );
+    static_assert ( !(o2 >= o3), "" );
+    static_assert ( !(o2 >= o4), "" );
+    static_assert ( !(o2 >= o5), "" );
+
+    static_assert (  (o3 >= o1), "" );
+    static_assert (  (o3 >= o2), "" );
+    static_assert (  (o3 >= o3), "" );
+    static_assert ( !(o3 >= o4), "" );
+    static_assert (  (o3 >= o5), "" );
+
+    static_assert (  (o4 >= o1), "" );
+    static_assert (  (o4 >= o2), "" );
+    static_assert (  (o4 >= o3), "" );
+    static_assert (  (o4 >= o4), "" );
+    static_assert (  (o4 >= o5), "" );
+
+    static_assert (  (o5 >= o1), "" );
+    static_assert (  (o5 >= o2), "" );
+    static_assert (  (o5 >= o3), "" );
+    static_assert ( !(o5 >= o4), "" );
+    static_assert (  (o5 >= o5), "" );
+    }
+}
Index: test/std/utilities/optional/optional.relops/greater_than.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.relops/greater_than.pass.cpp
@@ -0,0 +1,70 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// <optional>
+
+// template <class T> constexpr bool operator> (const optional<T>& x, const optional<T>& y);
+
+#include <optional>
+
+using std::optional;
+
+struct X
+{
+    int i_;
+
+    constexpr X(int i) : i_(i) {}
+};
+
+constexpr bool operator > ( const X &lhs, const X &rhs )
+    { return lhs.i_ > rhs.i_ ; }
+
+int main()
+{
+    {
+    typedef optional<X> O;
+
+    constexpr O o1;     // disengaged
+    constexpr O o2;     // disengaged
+    constexpr O o3{1};  // engaged
+    constexpr O o4{2};  // engaged
+    constexpr O o5{1};  // engaged
+
+    static_assert ( !(o1 > o1), "" );
+    static_assert ( !(o1 > o2), "" );
+    static_assert ( !(o1 > o3), "" );
+    static_assert ( !(o1 > o4), "" );
+    static_assert ( !(o1 > o5), "" );
+
+    static_assert ( !(o2 > o1), "" );
+    static_assert ( !(o2 > o2), "" );
+    static_assert ( !(o2 > o3), "" );
+    static_assert ( !(o2 > o4), "" );
+    static_assert ( !(o2 > o5), "" );
+
+    static_assert (  (o3 > o1), "" );
+    static_assert (  (o3 > o2), "" );
+    static_assert ( !(o3 > o3), "" );
+    static_assert ( !(o3 > o4), "" );
+    static_assert ( !(o3 > o5), "" );
+
+    static_assert (  (o4 > o1), "" );
+    static_assert (  (o4 > o2), "" );
+    static_assert (  (o4 > o3), "" );
+    static_assert ( !(o4 > o4), "" );
+    static_assert (  (o4 > o5), "" );
+
+    static_assert (  (o5 > o1), "" );
+    static_assert (  (o5 > o2), "" );
+    static_assert ( !(o5 > o3), "" );
+    static_assert ( !(o5 > o4), "" );
+    static_assert ( !(o5 > o5), "" );
+    }
+}
Index: test/std/utilities/optional/optional.relops/less_equal.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.relops/less_equal.pass.cpp
@@ -0,0 +1,70 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// <optional>
+
+// template <class T> constexpr bool operator<= (const optional<T>& x, const optional<T>& y);
+
+#include <optional>
+
+using std::optional;
+
+struct X
+{
+    int i_;
+
+    constexpr X(int i) : i_(i) {}
+};
+
+constexpr bool operator <= ( const X &lhs, const X &rhs )
+    { return lhs.i_ <= rhs.i_ ; }
+
+int main()
+{
+    {
+    typedef optional<X> O;
+
+    constexpr O o1;     // disengaged
+    constexpr O o2;     // disengaged
+    constexpr O o3{1};  // engaged
+    constexpr O o4{2};  // engaged
+    constexpr O o5{1};  // engaged
+
+    static_assert (  (o1 <= o1), "" );
+    static_assert (  (o1 <= o2), "" );
+    static_assert (  (o1 <= o3), "" );
+    static_assert (  (o1 <= o4), "" );
+    static_assert (  (o1 <= o5), "" );
+
+    static_assert (  (o2 <= o1), "" );
+    static_assert (  (o2 <= o2), "" );
+    static_assert (  (o2 <= o3), "" );
+    static_assert (  (o2 <= o4), "" );
+    static_assert (  (o2 <= o5), "" );
+
+    static_assert ( !(o3 <= o1), "" );
+    static_assert ( !(o3 <= o2), "" );
+    static_assert (  (o3 <= o3), "" );
+    static_assert (  (o3 <= o4), "" );
+    static_assert (  (o3 <= o5), "" );
+
+    static_assert ( !(o4 <= o1), "" );
+    static_assert ( !(o4 <= o2), "" );
+    static_assert ( !(o4 <= o3), "" );
+    static_assert (  (o4 <= o4), "" );
+    static_assert ( !(o4 <= o5), "" );
+
+    static_assert ( !(o5 <= o1), "" );
+    static_assert ( !(o5 <= o2), "" );
+    static_assert (  (o5 <= o3), "" );
+    static_assert (  (o5 <= o4), "" );
+    static_assert (  (o5 <= o5), "" );
+    }
+}
Index: test/std/utilities/optional/optional.relops/less_than.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.relops/less_than.pass.cpp
@@ -0,0 +1,70 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// <optional>
+
+// template <class T> constexpr bool operator< (const optional<T>& x, const optional<T>& y);
+
+#include <optional>
+
+using std::optional;
+
+struct X
+{
+    int i_;
+
+    constexpr X(int i) : i_(i) {}
+};
+
+constexpr bool operator < ( const X &lhs, const X &rhs )
+    { return lhs.i_ < rhs.i_ ; }
+
+int main()
+{
+    {
+    typedef optional<X> O;
+
+    constexpr O o1;     // disengaged
+    constexpr O o2;     // disengaged
+    constexpr O o3{1};  // engaged
+    constexpr O o4{2};  // engaged
+    constexpr O o5{1};  // engaged
+
+    static_assert ( !(o1 < o1), "" );
+    static_assert ( !(o1 < o2), "" );
+    static_assert (  (o1 < o3), "" );
+    static_assert (  (o1 < o4), "" );
+    static_assert (  (o1 < o5), "" );
+
+    static_assert ( !(o2 < o1), "" );
+    static_assert ( !(o2 < o2), "" );
+    static_assert (  (o2 < o3), "" );
+    static_assert (  (o2 < o4), "" );
+    static_assert (  (o2 < o5), "" );
+
+    static_assert ( !(o3 < o1), "" );
+    static_assert ( !(o3 < o2), "" );
+    static_assert ( !(o3 < o3), "" );
+    static_assert (  (o3 < o4), "" );
+    static_assert ( !(o3 < o5), "" );
+
+    static_assert ( !(o4 < o1), "" );
+    static_assert ( !(o4 < o2), "" );
+    static_assert ( !(o4 < o3), "" );
+    static_assert ( !(o4 < o4), "" );
+    static_assert ( !(o4 < o5), "" );
+
+    static_assert ( !(o5 < o1), "" );
+    static_assert ( !(o5 < o2), "" );
+    static_assert ( !(o5 < o3), "" );
+    static_assert (  (o5 < o4), "" );
+    static_assert ( !(o5 < o5), "" );
+    }
+}
Index: test/std/utilities/optional/optional.relops/not_equal.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.relops/not_equal.pass.cpp
@@ -0,0 +1,74 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// <optional>
+
+// template <class T> constexpr bool operator!=(const optional<T>& x, const optional<T>& y);
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+using std::optional;
+
+struct X
+{
+    int i_;
+
+    constexpr X(int i) : i_(i) {}
+};
+
+constexpr bool operator != ( const X &lhs, const X &rhs )
+    { return lhs.i_ != rhs.i_ ; }
+
+int main()
+{
+    {
+    typedef X T;
+    typedef optional<T> O;
+
+    constexpr O o1;     // disengaged
+    constexpr O o2;     // disengaged
+    constexpr O o3{1};  // engaged
+    constexpr O o4{2};  // engaged
+    constexpr O o5{1};  // engaged
+
+    static_assert ( !(o1 != o1), "" );
+    static_assert ( !(o1 != o2), "" );
+    static_assert (  (o1 != o3), "" );
+    static_assert (  (o1 != o4), "" );
+    static_assert (  (o1 != o5), "" );
+
+    static_assert ( !(o2 != o1), "" );
+    static_assert ( !(o2 != o2), "" );
+    static_assert (  (o2 != o3), "" );
+    static_assert (  (o2 != o4), "" );
+    static_assert (  (o2 != o5), "" );
+
+    static_assert (  (o3 != o1), "" );
+    static_assert (  (o3 != o2), "" );
+    static_assert ( !(o3 != o3), "" );
+    static_assert (  (o3 != o4), "" );
+    static_assert ( !(o3 != o5), "" );
+
+    static_assert (  (o4 != o1), "" );
+    static_assert (  (o4 != o2), "" );
+    static_assert (  (o4 != o3), "" );
+    static_assert ( !(o4 != o4), "" );
+    static_assert (  (o4 != o5), "" );
+
+    static_assert (  (o5 != o1), "" );
+    static_assert (  (o5 != o2), "" );
+    static_assert ( !(o5 != o3), "" );
+    static_assert (  (o5 != o4), "" );
+    static_assert ( !(o5 != o5), "" );
+
+    }
+}
Index: test/std/utilities/optional/optional.specalg/make_optional.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.specalg/make_optional.pass.cpp
@@ -0,0 +1,41 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// <optional>
+
+// template <class T>
+//   constexpr optional<decay_t<T>> make_optional(T&& v);
+
+#include <optional>
+#include <string>
+#include <memory>
+#include <cassert>
+
+int main()
+{
+    using std::optional;
+    using std::make_optional;
+
+    {
+        optional<int> opt = make_optional(2);
+        assert(*opt == 2);
+    }
+    {
+        std::string s("123");
+        optional<std::string> opt = make_optional(s);
+        assert(*opt == s);
+    }
+    {
+        std::unique_ptr<int> s(new int(3));
+        optional<std::unique_ptr<int>> opt = make_optional(std::move(s));
+        assert(**opt == 3);
+        assert(s == nullptr);
+    }
+}
Index: test/std/utilities/optional/optional.specalg/make_optional_explicit.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.specalg/make_optional_explicit.pass.cpp
@@ -0,0 +1,45 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// <optional>
+
+// template <class T, class... Args>
+//   constexpr optional<T> make_optional(Args&&... args);
+
+#include <optional>
+#include <string>
+#include <memory>
+#include <cassert>
+
+int main()
+{
+    using std::optional;
+    using std::make_optional;
+
+    {
+        auto opt = make_optional<int>(2);
+        assert(*opt == 2);
+    }
+    {
+        std::string s("123");
+        auto opt = make_optional<std::string>(s);
+        assert(*opt == s);
+    }
+    {
+        std::unique_ptr<int> s(new int(3));
+        auto opt = make_optional<std::unique_ptr<int>>(std::move(s));
+        assert(**opt == 3);
+        assert(s == nullptr);
+    }
+    {
+        auto opt = make_optional<std::string>(4, 'X');
+        assert(*opt == "XXXX");
+    }
+}
Index: test/std/utilities/optional/optional.specalg/make_optional_explicit_initializer_list.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.specalg/make_optional_explicit_initializer_list.pass.cpp
@@ -0,0 +1,33 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// <optional>
+
+// template <class T, class U, class... Args>
+//   constexpr optional<T> make_optional(initializer_list<U> il, Args&&... args);
+
+#include <optional>
+#include <string>
+#include <memory>
+#include <cassert>
+
+int main()
+{
+    using std::make_optional;
+
+    {
+        auto opt = make_optional<std::string>({'1', '2', '3'});
+        assert(*opt == "123");
+    }
+    {
+        auto opt = make_optional<std::string>({'a', 'b', 'c'}, std::allocator<char>{});
+        assert(*opt == "abc");
+    }
+}
Index: test/std/utilities/optional/optional.specalg/swap.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.specalg/swap.pass.cpp
@@ -0,0 +1,300 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// XFAIL: libcpp-no-exceptions
+// <optional>
+
+// template <class T> void swap(optional<T>& x, optional<T>& y)
+//     noexcept(noexcept(x.swap(y)));
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+using std::optional;
+
+class X
+{
+    int i_;
+public:
+    static unsigned dtor_called;
+    X(int i) : i_(i) {}
+    X(X&& x) = default;
+    X& operator=(X&&) = default;
+    ~X() {++dtor_called;}
+
+    friend bool operator==(const X& x, const X& y) {return x.i_ == y.i_;}
+};
+
+unsigned X::dtor_called = 0;
+
+class Y
+{
+    int i_;
+public:
+    static unsigned dtor_called;
+    Y(int i) : i_(i) {}
+    Y(Y&&) = default;
+    ~Y() {++dtor_called;}
+
+    friend constexpr bool operator==(const Y& x, const Y& y) {return x.i_ == y.i_;}
+    friend void swap(Y& x, Y& y) {std::swap(x.i_, y.i_);}
+};
+
+unsigned Y::dtor_called = 0;
+
+class Z
+{
+    int i_;
+public:
+    Z(int i) : i_(i) {}
+    Z(Z&&) {throw 7;}
+
+    friend constexpr bool operator==(const Z& x, const Z& y) {return x.i_ == y.i_;}
+    friend void swap(Z& x, Z& y) {throw 6;}
+};
+
+int main()
+{
+    {
+        optional<int> opt1;
+        optional<int> opt2;
+        static_assert(noexcept(swap(opt1, opt2)) == true, "");
+        assert(static_cast<bool>(opt1) == false);
+        assert(static_cast<bool>(opt2) == false);
+        swap(opt1, opt2);
+        assert(static_cast<bool>(opt1) == false);
+        assert(static_cast<bool>(opt2) == false);
+    }
+    {
+        optional<int> opt1(1);
+        optional<int> opt2;
+        static_assert(noexcept(swap(opt1, opt2)) == true, "");
+        assert(static_cast<bool>(opt1) == true);
+        assert(*opt1 == 1);
+        assert(static_cast<bool>(opt2) == false);
+        swap(opt1, opt2);
+        assert(static_cast<bool>(opt1) == false);
+        assert(static_cast<bool>(opt2) == true);
+        assert(*opt2 == 1);
+    }
+    {
+        optional<int> opt1;
+        optional<int> opt2(2);
+        static_assert(noexcept(swap(opt1, opt2)) == true, "");
+        assert(static_cast<bool>(opt1) == false);
+        assert(static_cast<bool>(opt2) == true);
+        assert(*opt2 == 2);
+        swap(opt1, opt2);
+        assert(static_cast<bool>(opt1) == true);
+        assert(*opt1 == 2);
+        assert(static_cast<bool>(opt2) == false);
+    }
+    {
+        optional<int> opt1(1);
+        optional<int> opt2(2);
+        static_assert(noexcept(swap(opt1, opt2)) == true, "");
+        assert(static_cast<bool>(opt1) == true);
+        assert(*opt1 == 1);
+        assert(static_cast<bool>(opt2) == true);
+        assert(*opt2 == 2);
+        swap(opt1, opt2);
+        assert(static_cast<bool>(opt1) == true);
+        assert(*opt1 == 2);
+        assert(static_cast<bool>(opt2) == true);
+        assert(*opt2 == 1);
+    }
+    {
+        optional<X> opt1;
+        optional<X> opt2;
+        static_assert(noexcept(swap(opt1, opt2)) == true, "");
+        assert(static_cast<bool>(opt1) == false);
+        assert(static_cast<bool>(opt2) == false);
+        swap(opt1, opt2);
+        assert(static_cast<bool>(opt1) == false);
+        assert(static_cast<bool>(opt2) == false);
+        assert(X::dtor_called == 0);
+    }
+    {
+        optional<X> opt1(1);
+        optional<X> opt2;
+        static_assert(noexcept(swap(opt1, opt2)) == true, "");
+        assert(static_cast<bool>(opt1) == true);
+        assert(*opt1 == 1);
+        assert(static_cast<bool>(opt2) == false);
+        X::dtor_called = 0;
+        swap(opt1, opt2);
+        assert(X::dtor_called == 1);
+        assert(static_cast<bool>(opt1) == false);
+        assert(static_cast<bool>(opt2) == true);
+        assert(*opt2 == 1);
+    }
+    {
+        optional<X> opt1;
+        optional<X> opt2(2);
+        static_assert(noexcept(swap(opt1, opt2)) == true, "");
+        assert(static_cast<bool>(opt1) == false);
+        assert(static_cast<bool>(opt2) == true);
+        assert(*opt2 == 2);
+        X::dtor_called = 0;
+        swap(opt1, opt2);
+        assert(X::dtor_called == 1);
+        assert(static_cast<bool>(opt1) == true);
+        assert(*opt1 == 2);
+        assert(static_cast<bool>(opt2) == false);
+    }
+    {
+        optional<X> opt1(1);
+        optional<X> opt2(2);
+        static_assert(noexcept(swap(opt1, opt2)) == true, "");
+        assert(static_cast<bool>(opt1) == true);
+        assert(*opt1 == 1);
+        assert(static_cast<bool>(opt2) == true);
+        assert(*opt2 == 2);
+        X::dtor_called = 0;
+        swap(opt1, opt2);
+        assert(X::dtor_called == 1);  // from inside std::swap
+        assert(static_cast<bool>(opt1) == true);
+        assert(*opt1 == 2);
+        assert(static_cast<bool>(opt2) == true);
+        assert(*opt2 == 1);
+    }
+    {
+        optional<Y> opt1;
+        optional<Y> opt2;
+        static_assert(noexcept(swap(opt1, opt2)) == false, "");
+        assert(static_cast<bool>(opt1) == false);
+        assert(static_cast<bool>(opt2) == false);
+        swap(opt1, opt2);
+        assert(static_cast<bool>(opt1) == false);
+        assert(static_cast<bool>(opt2) == false);
+        assert(Y::dtor_called == 0);
+    }
+    {
+        optional<Y> opt1(1);
+        optional<Y> opt2;
+        static_assert(noexcept(swap(opt1, opt2)) == false, "");
+        assert(static_cast<bool>(opt1) == true);
+        assert(*opt1 == 1);
+        assert(static_cast<bool>(opt2) == false);
+        Y::dtor_called = 0;
+        swap(opt1, opt2);
+        assert(Y::dtor_called == 1);
+        assert(static_cast<bool>(opt1) == false);
+        assert(static_cast<bool>(opt2) == true);
+        assert(*opt2 == 1);
+    }
+    {
+        optional<Y> opt1;
+        optional<Y> opt2(2);
+        static_assert(noexcept(swap(opt1, opt2)) == false, "");
+        assert(static_cast<bool>(opt1) == false);
+        assert(static_cast<bool>(opt2) == true);
+        assert(*opt2 == 2);
+        Y::dtor_called = 0;
+        swap(opt1, opt2);
+        assert(Y::dtor_called == 1);
+        assert(static_cast<bool>(opt1) == true);
+        assert(*opt1 == 2);
+        assert(static_cast<bool>(opt2) == false);
+    }
+    {
+        optional<Y> opt1(1);
+        optional<Y> opt2(2);
+        static_assert(noexcept(swap(opt1, opt2)) == false, "");
+        assert(static_cast<bool>(opt1) == true);
+        assert(*opt1 == 1);
+        assert(static_cast<bool>(opt2) == true);
+        assert(*opt2 == 2);
+        Y::dtor_called = 0;
+        swap(opt1, opt2);
+        assert(Y::dtor_called == 0);
+        assert(static_cast<bool>(opt1) == true);
+        assert(*opt1 == 2);
+        assert(static_cast<bool>(opt2) == true);
+        assert(*opt2 == 1);
+    }
+    {
+        optional<Z> opt1;
+        optional<Z> opt2;
+        static_assert(noexcept(swap(opt1, opt2)) == false, "");
+        assert(static_cast<bool>(opt1) == false);
+        assert(static_cast<bool>(opt2) == false);
+        swap(opt1, opt2);
+        assert(static_cast<bool>(opt1) == false);
+        assert(static_cast<bool>(opt2) == false);
+    }
+    {
+        optional<Z> opt1;
+        opt1.emplace(1);
+        optional<Z> opt2;
+        static_assert(noexcept(swap(opt1, opt2)) == false, "");
+        assert(static_cast<bool>(opt1) == true);
+        assert(*opt1 == 1);
+        assert(static_cast<bool>(opt2) == false);
+        try
+        {
+            swap(opt1, opt2);
+            assert(false);
+        }
+        catch (int i)
+        {
+            assert(i == 7);
+        }
+        assert(static_cast<bool>(opt1) == true);
+        assert(*opt1 == 1);
+        assert(static_cast<bool>(opt2) == false);
+    }
+    {
+        optional<Z> opt1;
+        optional<Z> opt2;
+        opt2.emplace(2);
+        static_assert(noexcept(swap(opt1, opt2)) == false, "");
+        assert(static_cast<bool>(opt1) == false);
+        assert(static_cast<bool>(opt2) == true);
+        assert(*opt2 == 2);
+        try
+        {
+            swap(opt1, opt2);
+            assert(false);
+        }
+        catch (int i)
+        {
+            assert(i == 7);
+        }
+        assert(static_cast<bool>(opt1) == false);
+        assert(static_cast<bool>(opt2) == true);
+        assert(*opt2 == 2);
+    }
+    {
+        optional<Z> opt1;
+        opt1.emplace(1);
+        optional<Z> opt2;
+        opt2.emplace(2);
+        static_assert(noexcept(swap(opt1, opt2)) == false, "");
+        assert(static_cast<bool>(opt1) == true);
+        assert(*opt1 == 1);
+        assert(static_cast<bool>(opt2) == true);
+        assert(*opt2 == 2);
+        try
+        {
+            swap(opt1, opt2);
+            assert(false);
+        }
+        catch (int i)
+        {
+            assert(i == 6);
+        }
+        assert(static_cast<bool>(opt1) == true);
+        assert(*opt1 == 1);
+        assert(static_cast<bool>(opt2) == true);
+        assert(*opt2 == 2);
+    }
+}
Index: test/std/utilities/optional/optional.syn/optional_const_in_place_t.fail.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.syn/optional_const_in_place_t.fail.cpp
@@ -0,0 +1,25 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// <optional>
+
+// A program that necessitates the instantiation of template optional for
+// (possibly cv-qualified) in_place_t is ill-formed.
+
+#include <optional>
+
+int main()
+{
+    using std::optional;
+    using std::in_place_t;
+    using std::in_place;
+
+    optional<const in_place_t> opt;
+}
Index: test/std/utilities/optional/optional.syn/optional_const_lvalue_ref.fail.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.syn/optional_const_lvalue_ref.fail.cpp
@@ -0,0 +1,23 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// <optional>
+
+// A program that necessitates the instantiation of template optional for a
+// reference type is ill-formed.
+
+#include <optional>
+
+int main()
+{
+    using std::optional;
+
+    optional<const int&> opt;
+}
Index: test/std/utilities/optional/optional.syn/optional_const_nullopt_t.fail.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.syn/optional_const_nullopt_t.fail.cpp
@@ -0,0 +1,25 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// <optional>
+
+// A program that necessitates the instantiation of template optional for
+// (possibly cv-qualified) nullopt_t is ill-formed.
+
+#include <optional>
+
+int main()
+{
+    using std::optional;
+    using std::nullopt_t;
+    using std::nullopt;
+
+    optional<const nullopt_t> opt;
+}
Index: test/std/utilities/optional/optional.syn/optional_in_place_t.fail.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.syn/optional_in_place_t.fail.cpp
@@ -0,0 +1,25 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// <optional>
+
+// A program that necessitates the instantiation of template optional for
+// (possibly cv-qualified) in_place_t is ill-formed.
+
+#include <optional>
+
+int main()
+{
+    using std::optional;
+    using std::in_place_t;
+    using std::in_place;
+
+    optional<in_place_t> opt;
+}
Index: test/std/utilities/optional/optional.syn/optional_includes_initializer_list.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.syn/optional_includes_initializer_list.pass.cpp
@@ -0,0 +1,22 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// <optional>
+
+// #include <initializer_list>
+
+#include <optional>
+
+int main()
+{
+    using std::optional;
+
+    std::initializer_list<int> list;
+}
Index: test/std/utilities/optional/optional.syn/optional_lvalue_ref.fail.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.syn/optional_lvalue_ref.fail.cpp
@@ -0,0 +1,23 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// <optional>
+
+// A program that necessitates the instantiation of template optional for a
+// reference type is ill-formed.
+
+#include <optional>
+
+int main()
+{
+    using std::optional;
+
+    optional<int&> opt;
+}
Index: test/std/utilities/optional/optional.syn/optional_nullopt_t.fail.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.syn/optional_nullopt_t.fail.cpp
@@ -0,0 +1,25 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// <optional>
+
+// A program that necessitates the instantiation of template optional for
+// (possibly cv-qualified) nullopt_t is ill-formed.
+
+#include <optional>
+
+int main()
+{
+    using std::optional;
+    using std::nullopt_t;
+    using std::nullopt;
+
+    optional<nullopt_t> opt;
+}
Index: test/std/utilities/optional/optional.syn/optional_rvalue_ref.fail.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/optional/optional.syn/optional_rvalue_ref.fail.cpp
@@ -0,0 +1,23 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+// <optional>
+
+// A program that necessitates the instantiation of template optional for a
+// reference type is ill-formed.
+
+#include <optional>
+
+int main()
+{
+    using std::optional;
+
+    optional<int&&> opt;
+}