Implement N4606 optional

Summary:
Adapt implementation of Library Fundamentals TS optional into an implementation of N4606 optional.

  - Update relational operators per http://wg21.link/P0307
  - Update to requirements of http://wg21.link/P0032
  - Extension: Implement trivial copy/move construction/assignment for `optional<T>` when `T` is trivially copyable.

Audit P/Rs for optional LWG issues:
  - 2756 "C++ WP optional<T> should 'forward' T's implicit conversions" Implemented, which also resolves 2753 "Optional's constructors and assignments need constraints" (modulo my refusal to explicitly delete the move operations, which is a design error that I'm working on correcting in the 2756 P/R).
  - 2736 "nullopt_t insufficiently constrained" Already conforming. I've added a test ensuring that `nullopt_t` is not copy-initializable from an empty braced-init-list, which I believe is the root intent of the issue, to avoid regression.
  - 2740 "constexpr optional<T>::operator->" Already conforming.
  - 2746 "Inconsistency between requirements for emplace between optional and variant" No P/R, but note that the author's '"suggested resolution" is already implemented.
  - 2748 "swappable traits for optionals" Already conforming.
  - 2753 "Optional's constructors and assignments need constraints" Implemented.

Most of the work for this patch was done by Casey Carter @ Microsoft. Thank you Casey!



Reviewers: mclow.lists, CaseyCarter, EricWF

Differential Revision: https://reviews.llvm.org/D22741

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@283980 91177308-0d34-0410-b5e6-96231b3b80d8

test/std/utilities/optional/optional.object/optional.object.assign/assign_value.pass.cpp

@@ -0,0 +1,261 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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>
+
+#include "test_macros.h"
+#include "archetypes.hpp"
+
+using std::optional;
+
+struct ThrowAssign {
+  static int dtor_called;
+  ThrowAssign() = default;
+  ThrowAssign(int) { TEST_THROW(42); }
+  ThrowAssign& operator=(int) {
+      TEST_THROW(42);
+  }
+  ~ThrowAssign() { ++dtor_called; }
+};
+int ThrowAssign::dtor_called = 0;
+
+template <class T, class Arg = T, bool Expect = true>
+void assert_assignable() {
+    static_assert(std::is_assignable<optional<T>&, Arg>::value == Expect, "");
+    static_assert(!std::is_assignable<const optional<T>&, Arg>::value, "");
+}
+
+struct MismatchType {
+  explicit MismatchType(int) {}
+  explicit MismatchType(char*) {}
+  explicit MismatchType(int*) = delete;
+  MismatchType& operator=(int) { return *this; }
+  MismatchType& operator=(int*) { return *this; }
+  MismatchType& operator=(char*) = delete;
+};
+
+void test_sfinae() {
+    using I = TestTypes::TestType;
+    using E = ExplicitTestTypes::TestType;
+    assert_assignable<int>();
+    assert_assignable<int, int&>();
+    assert_assignable<int, int const&>();
+    // Implicit test type
+    assert_assignable<I, I const&>();
+    assert_assignable<I, I&&>();
+    assert_assignable<I, int>();
+    assert_assignable<I, void*, false>();
+    // Explicit test type
+    assert_assignable<E, E const&>();
+    assert_assignable<E, E &&>();
+    assert_assignable<E, int>();
+    assert_assignable<E, void*, false>();
+    // Mismatch type
+    assert_assignable<MismatchType, int>();
+    assert_assignable<MismatchType, int*, false>();
+    assert_assignable<MismatchType, char*, false>();
+}
+
+void test_with_test_type()
+{
+    using T = TestTypes::TestType;
+    T::reset();
+    { // to empty
+        optional<T> opt;
+        opt = 3;
+        assert(T::alive == 1);
+        assert(T::constructed == 1);
+        assert(T::value_constructed == 1);
+        assert(T::assigned == 0);
+        assert(T::destroyed == 0);
+        assert(static_cast<bool>(opt) == true);
+        assert(*opt == T(3));
+    }
+    { // to existing
+        optional<T> opt(42);
+        T::reset_constructors();
+        opt = 3;
+        assert(T::alive == 1);
+        assert(T::constructed == 0);
+        assert(T::assigned == 1);
+        assert(T::value_assigned == 1);
+        assert(T::destroyed == 0);
+        assert(static_cast<bool>(opt) == true);
+        assert(*opt == T(3));
+    }
+    { // test default argument
+        optional<T> opt;
+        T::reset_constructors();
+        opt = {1, 2};
+        assert(T::alive == 1);
+        assert(T::constructed == 2);
+        assert(T::value_constructed == 1);
+        assert(T::move_constructed == 1);
+        assert(T::assigned == 0);
+        assert(T::destroyed == 1);
+        assert(static_cast<bool>(opt) == true);
+        assert(*opt == T(1, 2));
+    }
+    { // test default argument
+        optional<T> opt(42);
+        T::reset_constructors();
+        opt = {1, 2};
+        assert(T::alive == 1);
+        assert(T::constructed == 1);
+        assert(T::value_constructed == 1);
+        assert(T::assigned == 1);
+        assert(T::move_assigned == 1);
+        assert(T::destroyed == 1);
+        assert(static_cast<bool>(opt) == true);
+        assert(*opt == T(1, 2));
+    }
+    { // test default argument
+        optional<T> opt;
+        T::reset_constructors();
+        opt = {1};
+        assert(T::alive == 1);
+        assert(T::constructed == 2);
+        assert(T::value_constructed == 1);
+        assert(T::move_constructed == 1);
+        assert(T::assigned == 0);
+        assert(T::destroyed == 1);
+        assert(static_cast<bool>(opt) == true);
+        assert(*opt == T(1));
+    }
+    { // test default argument
+        optional<T> opt(42);
+        T::reset_constructors();
+        opt = {};
+        assert(static_cast<bool>(opt) == false);
+        assert(T::alive == 0);
+        assert(T::constructed == 0);
+        assert(T::assigned == 0);
+        assert(T::destroyed == 1);
+    }
+}
+
+template <class T, class Value = int>
+void test_with_type() {
+    { // to empty
+        optional<T> opt;
+        opt = Value(3);
+        assert(static_cast<bool>(opt) == true);
+        assert(*opt == T(3));
+    }
+    { // to existing
+        optional<T> opt(Value(42));
+        opt = Value(3);
+        assert(static_cast<bool>(opt) == true);
+        assert(*opt == T(3));
+    }
+    { // test const
+        optional<T> opt(Value(42));
+        const T t(Value(3));
+        opt = t;
+        assert(static_cast<bool>(opt) == true);
+        assert(*opt == T(3));
+    }
+    { // test default argument
+        optional<T> opt;
+        opt = {Value(1)};
+        assert(static_cast<bool>(opt) == true);
+        assert(*opt == T(1));
+    }
+    { // test default argument
+        optional<T> opt(Value(42));
+        opt = {};
+        assert(static_cast<bool>(opt) == false);
+    }
+}
+
+template <class T>
+void test_with_type_multi() {
+    test_with_type<T>();
+    { // test default argument
+        optional<T> opt;
+        opt = {1, 2};
+        assert(static_cast<bool>(opt) == true);
+        assert(*opt == T(1, 2));
+    }
+    { // test default argument
+        optional<T> opt(42);
+        opt = {1, 2};
+        assert(static_cast<bool>(opt) == true);
+        assert(*opt == T(1, 2));
+    }
+}
+
+void test_throws()
+{
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    using T = ThrowAssign;
+    {
+        using T = ThrowAssign;
+        optional<T> opt;
+        try {
+            opt = 42;
+            assert(false);
+        } catch (int) {}
+        assert(static_cast<bool>(opt) == false);
+    }
+    assert(T::dtor_called == 0);
+    {
+        T::dtor_called = 0;
+        optional<T> opt(std::in_place);
+        try {
+            opt = 42;
+            assert(false);
+        } catch (int) {}
+        assert(static_cast<bool>(opt) == true);
+        assert(T::dtor_called == 0);
+    }
+    assert(T::dtor_called == 1);
+#endif
+}
+
+enum MyEnum { Zero, One, Two, Three, FortyTwo = 42 };
+
+using Fn = void(*)();
+
+int main()
+{
+    test_sfinae();
+    // Test with instrumented type
+    test_with_test_type();
+    // Test with various scalar types
+    test_with_type<int>();
+    test_with_type<MyEnum, MyEnum>();
+    test_with_type<int, MyEnum>();
+    test_with_type<Fn, Fn>();
+    // Test types with multi argument constructors
+    test_with_type_multi<ConstexprTestTypes::TestType>();
+    test_with_type_multi<TrivialTestTypes::TestType>();
+    // Test move only types
+    {
+        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);
+    }
+    test_throws();
+}

test/std/utilities/optional/optional.object/optional.object.assign/const_optional_U.pass.cpp

@@ -0,0 +1,254 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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>
+
+// From LWG2451:
+// template<class U>
+//   optional<T>& operator=(const optional<U>& rhs);
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+#include "test_macros.h"
+#include "archetypes.hpp"
+
+using std::optional;
+
+struct X
+{
+    static bool throw_now;
+
+    X() = default;
+    X(int)
+    {
+        if (throw_now)
+            TEST_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; }
+};
+
+template <class T>
+struct AssignableFrom {
+  static int type_constructed;
+  static int type_assigned;
+static int int_constructed;
+  static int int_assigned;
+
+  static void reset() {
+      type_constructed = int_constructed = 0;
+      type_assigned = int_assigned = 0;
+  }
+
+  AssignableFrom() = default;
+
+  explicit AssignableFrom(T) { ++type_constructed; }
+  AssignableFrom& operator=(T) { ++type_assigned; return *this; }
+
+  AssignableFrom(int) { ++int_constructed; }
+  AssignableFrom& operator=(int) { ++int_assigned; return *this; }
+private:
+  AssignableFrom(AssignableFrom const&) = delete;
+  AssignableFrom& operator=(AssignableFrom const&) = delete;
+};
+
+template <class T> int AssignableFrom<T>::type_constructed = 0;
+template <class T> int AssignableFrom<T>::type_assigned = 0;
+template <class T> int AssignableFrom<T>::int_constructed = 0;
+template <class T> int AssignableFrom<T>::int_assigned = 0;
+
+
+void test_with_test_type() {
+    using T = TestTypes::TestType;
+    T::reset();
+    { // non-empty to empty
+        T::reset_constructors();
+        optional<T> opt;
+        const optional<int> other(42);
+        opt = other;
+        assert(T::alive == 1);
+        assert(T::constructed == 1);
+        assert(T::value_constructed == 1);
+        assert(T::assigned == 0);
+        assert(T::destroyed == 0);
+        assert(static_cast<bool>(other) == true);
+        assert(*other == 42);
+        assert(static_cast<bool>(opt) == true);
+        assert(*opt == T(42));
+    }
+    assert(T::alive == 0);
+    { // non-empty to non-empty
+        optional<T> opt(101);
+        const optional<int> other(42);
+        T::reset_constructors();
+        opt = other;
+        assert(T::alive == 1);
+        assert(T::constructed == 0);
+        assert(T::assigned == 1);
+        assert(T::value_assigned == 1);
+        assert(T::destroyed == 0);
+        assert(static_cast<bool>(other) == true);
+        assert(*other == 42);
+        assert(static_cast<bool>(opt) == true);
+        assert(*opt == T(42));
+    }
+    assert(T::alive == 0);
+    { // empty to non-empty
+        optional<T> opt(101);
+        const optional<int> other;
+        T::reset_constructors();
+        opt = other;
+        assert(T::alive == 0);
+        assert(T::constructed == 0);
+        assert(T::assigned == 0);
+        assert(T::destroyed == 1);
+        assert(static_cast<bool>(other) == false);
+        assert(static_cast<bool>(opt) == false);
+    }
+    assert(T::alive == 0);
+    { // empty to empty
+        optional<T> opt;
+        const optional<int> other;
+        T::reset_constructors();
+        opt = other;
+        assert(T::alive == 0);
+        assert(T::constructed == 0);
+        assert(T::assigned == 0);
+        assert(T::destroyed == 0);
+        assert(static_cast<bool>(other) == false);
+        assert(static_cast<bool>(opt) == false);
+    }
+    assert(T::alive == 0);
+}
+
+void test_ambigious_assign() {
+    using OptInt = std::optional<int>;
+    {
+        using T = AssignableFrom<OptInt const&>;
+        const OptInt a(42);
+        T::reset();
+        {
+            std::optional<T> t;
+            t = a;
+            assert(T::type_constructed == 1);
+            assert(T::type_assigned == 0);
+            assert(T::int_constructed == 0);
+            assert(T::int_assigned == 0);
+        }
+        T::reset();
+        {
+            std::optional<T> t(42);
+            t = a;
+            assert(T::type_constructed == 0);
+            assert(T::type_assigned == 1);
+            assert(T::int_constructed == 1);
+            assert(T::int_assigned == 0);
+        }
+        T::reset();
+        {
+            std::optional<T> t(42);
+            t = std::move(a);
+            assert(T::type_constructed == 0);
+            assert(T::type_assigned == 1);
+            assert(T::int_constructed == 1);
+            assert(T::int_assigned == 0);
+        }
+    }
+    {
+        using T = AssignableFrom<OptInt&>;
+        OptInt a(42);
+        T::reset();
+        {
+            std::optional<T> t;
+            t = a;
+            assert(T::type_constructed == 1);
+            assert(T::type_assigned == 0);
+            assert(T::int_constructed == 0);
+            assert(T::int_assigned == 0);
+        }
+        {
+            using Opt = std::optional<T>;
+            static_assert(!std::is_assignable_v<Opt&, OptInt const&>, "");
+        }
+    }
+}
+
+
+int main()
+{
+    test_with_test_type();
+    test_ambigious_assign();
+    {
+        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);
+    }
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    {
+        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);
+        }
+    }
+#endif
+}

test/std/utilities/optional/optional.object/optional.object.assign/copy.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
+// <optional>
+
+// optional<T>& operator=(const optional<T>& rhs);
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+#include "test_macros.h"
+#include "archetypes.hpp"
+
+using std::optional;
+
+struct X
+{
+    static bool throw_now;
+
+    X() = default;
+    X(const X&)
+    {
+        if (throw_now)
+            TEST_THROW(6);
+    }
+};
+
+bool X::throw_now = false;
+
+template <class Tp>
+constexpr bool assign_empty(optional<Tp>&& lhs) {
+    const optional<Tp> rhs;
+    lhs = rhs;
+    return !lhs.has_value() && !rhs.has_value();
+}
+
+template <class Tp>
+constexpr bool assign_value(optional<Tp>&& lhs) {
+    const optional<Tp> rhs(101);
+    lhs = rhs;
+    return lhs.has_value() && rhs.has_value() && *lhs == *rhs;
+}
+
+int main()
+{
+    {
+        using O = optional<int>;
+        LIBCPP_STATIC_ASSERT(assign_empty(O{42}), "");
+        LIBCPP_STATIC_ASSERT(assign_value(O{42}), "");
+        assert(assign_empty(O{42}));
+        assert(assign_value(O{42}));
+    }
+    {
+        using O = optional<TrivialTestTypes::TestType>;
+        LIBCPP_STATIC_ASSERT(assign_empty(O{42}), "");
+        LIBCPP_STATIC_ASSERT(assign_value(O{42}), "");
+        assert(assign_empty(O{42}));
+        assert(assign_value(O{42}));
+    }
+    {
+        using O = optional<TestTypes::TestType>;
+        assert(assign_empty(O{42}));
+        assert(assign_value(O{42}));
+    }
+    {
+        using T = TestTypes::TestType;
+        T::reset();
+        optional<T> opt(3);
+        const optional<T> opt2;
+        assert(T::alive == 1);
+        opt = opt2;
+        assert(T::alive == 0);
+        assert(!opt2.has_value());
+        assert(!opt.has_value());
+    }
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    {
+        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);
+        }
+    }
+#endif
+}

test/std/utilities/optional/optional.object/optional.object.assign/emplace.pass.cpp

@@ -0,0 +1,237 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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... Args> void optional<T>::emplace(Args&&... args);
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+#include <memory>
+
+#include "test_macros.h"
+#include "archetypes.hpp"
+
+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) { TEST_THROW(6);}
+    ~Y() {dtor_called = true;}
+};
+
+bool Y::dtor_called = false;
+
+template <class T>
+void test_one_arg() {
+    using Opt = std::optional<T>;
+    {
+        Opt opt;
+        opt.emplace();
+        assert(static_cast<bool>(opt) == true);
+        assert(*opt == T(0));
+    }
+    {
+        Opt opt;
+        opt.emplace(1);
+        assert(static_cast<bool>(opt) == true);
+        assert(*opt == T(1));
+    }
+    {
+        Opt opt(2);
+        opt.emplace();
+        assert(static_cast<bool>(opt) == true);
+        assert(*opt == T(0));
+    }
+    {
+        Opt opt(2);
+        opt.emplace(1);
+        assert(static_cast<bool>(opt) == true);
+        assert(*opt == T(1));
+    }
+}
+
+
+template <class T>
+void test_multi_arg()
+{
+    test_one_arg<T>();
+    using Opt = std::optional<T>;
+    Opt opt;
+    {
+        opt.emplace(101, 41);
+        assert(static_cast<bool>(opt) == true);
+        assert(*opt == T(101, 41));
+    }
+    {
+        Opt opt;
+        opt.emplace({1, 2, 3, 4});
+        assert(static_cast<bool>(opt) == true);
+        assert(*opt == T(4)); // T sets its value to the size of the init list
+    }
+    {
+        Opt opt;
+        opt.emplace({1, 2, 3, 4, 5}, 6);
+        assert(static_cast<bool>(opt) == true);
+        assert(*opt == T(5)); // T sets its value to the size of the init list
+    }
+}
+
+template <class T>
+void test_on_test_type() {
+
+    T::reset();
+    optional<T> opt;
+    assert(T::alive == 0);
+    {
+        T::reset_constructors();
+        opt.emplace();
+        assert(T::alive == 1);
+        assert(T::constructed == 1);
+        assert(T::default_constructed == 1);
+        assert(T::destroyed == 0);
+        assert(static_cast<bool>(opt) == true);
+        assert(*opt == T());
+    }
+    {
+        T::reset_constructors();
+        opt.emplace();
+        assert(T::alive == 1);
+        assert(T::constructed == 1);
+        assert(T::default_constructed == 1);
+        assert(T::destroyed == 1);
+        assert(static_cast<bool>(opt) == true);
+        assert(*opt == T());
+    }
+    {
+        T::reset_constructors();
+        opt.emplace(101);
+        assert(T::alive == 1);
+        assert(T::constructed == 1);
+        assert(T::value_constructed == 1);
+        assert(T::destroyed == 1);
+        assert(static_cast<bool>(opt) == true);
+        assert(*opt == T(101));
+    }
+    {
+        T::reset_constructors();
+        opt.emplace(-10, 99);
+        assert(T::alive == 1);
+        assert(T::constructed == 1);
+        assert(T::value_constructed == 1);
+        assert(T::destroyed == 1);
+        assert(static_cast<bool>(opt) == true);
+        assert(*opt == T(-10, 99));
+    }
+    {
+        T::reset_constructors();
+        opt.emplace(-10, 99);
+        assert(T::alive == 1);
+        assert(T::constructed == 1);
+        assert(T::value_constructed == 1);
+        assert(T::destroyed == 1);
+        assert(static_cast<bool>(opt) == true);
+        assert(*opt == T(-10, 99));
+    }
+    {
+        T::reset_constructors();
+        opt.emplace({-10, 99, 42, 1});
+        assert(T::alive == 1);
+        assert(T::constructed == 1);
+        assert(T::value_constructed == 1);
+        assert(T::destroyed == 1);
+        assert(static_cast<bool>(opt) == true);
+        assert(*opt == T(4)); // size of the initializer list
+    }
+    {
+        T::reset_constructors();
+        opt.emplace({-10, 99, 42, 1}, 42);
+        assert(T::alive == 1);
+        assert(T::constructed == 1);
+        assert(T::value_constructed == 1);
+        assert(T::destroyed == 1);
+        assert(static_cast<bool>(opt) == true);
+        assert(*opt == T(4)); // size of the initializer list
+    }
+}
+
+
+
+int main()
+{
+    {
+        test_on_test_type<TestTypes::TestType>();
+        test_on_test_type<ExplicitTestTypes::TestType>();
+    }
+    {
+        using T = int;
+        test_one_arg<T>();
+        test_one_arg<const T>();
+    }
+    {
+        using T = ConstexprTestTypes::TestType;
+        test_multi_arg<T>();
+    }
+    {
+        using T = ExplicitConstexprTestTypes::TestType;
+        test_multi_arg<T>();
+    }
+    {
+        using T = TrivialTestTypes::TestType;
+        test_multi_arg<T>();
+    }
+    {
+        using T = ExplicitTrivialTestTypes::TestType;
+        test_multi_arg<T>();
+    }
+    {
+        optional<const int> opt;
+        opt.emplace(42);
+        assert(*opt == 42);
+        opt.emplace();
+        assert(*opt == 0);
+    }
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    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);
+        }
+    }
+#endif
+}

test/std/utilities/optional/optional.object/optional.object.assign/emplace_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
+// <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>
+
+#include "test_macros.h"
+
+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])
+        { TEST_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}));
+    }
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    {
+        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);
+        }
+    }
+#endif
+}

test/std/utilities/optional/optional.object/optional.object.assign/move.pass.cpp

@@ -0,0 +1,174 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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=(optional<T>&& rhs)
+//     noexcept(is_nothrow_move_assignable<T>::value &&
+//              is_nothrow_move_constructible<T>::value);
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+#include "test_macros.h"
+#include "archetypes.hpp"
+
+using std::optional;
+
+struct X
+{
+    static bool throw_now;
+    static int alive;
+
+    X() { ++alive; }
+    X(X&&)
+    {
+        if (throw_now)
+            TEST_THROW(6);
+        ++alive;
+    }
+
+    X& operator=(X&&)
+    {
+        if (throw_now)
+            TEST_THROW(42);
+        return *this;
+    }
+
+    ~X() { assert(alive > 0); --alive; }
+};
+
+struct Y {};
+
+bool X::throw_now = false;
+int X::alive = 0;
+
+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));
+    }
+    {
+        using T = TestTypes::TestType;
+        T::reset();
+        optional<T> opt(3);
+        optional<T> opt2;
+        assert(T::alive == 1);
+        opt = std::move(opt2);
+        assert(T::alive == 0);
+        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);
+    }
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    {
+        static_assert(!std::is_nothrow_move_assignable<optional<X>>::value, "");
+        X::alive = 0;
+        X::throw_now = false;
+        optional<X> opt;
+        optional<X> opt2(X{});
+        assert(X::alive == 1);
+        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);
+        }
+        assert(X::alive == 1);
+    }
+    assert(X::alive == 0);
+    {
+        static_assert(!std::is_nothrow_move_assignable<optional<X>>::value, "");
+        X::throw_now = false;
+        optional<X> opt(X{});
+        optional<X> opt2(X{});
+        assert(X::alive == 2);
+        assert(static_cast<bool>(opt2) == true);
+        try
+        {
+            X::throw_now = true;
+            opt = std::move(opt2);
+            assert(false);
+        }
+        catch (int i)
+        {
+            assert(i == 42);
+            assert(static_cast<bool>(opt) == true);
+        }
+        assert(X::alive == 2);
+    }
+    assert(X::alive == 0);
+#endif // TEST_HAS_NO_EXCEPTIONS
+    {
+        static_assert(std::is_nothrow_move_assignable<optional<Y>>::value, "");
+    }
+    {
+        struct ThrowsMove {
+          ThrowsMove() noexcept {}
+          ThrowsMove(ThrowsMove const&) noexcept {}
+          ThrowsMove(ThrowsMove &&) noexcept(false) {}
+          ThrowsMove& operator=(ThrowsMove const&) noexcept { return *this; }
+          ThrowsMove& operator=(ThrowsMove &&) noexcept { return *this; }
+        };
+        static_assert(!std::is_nothrow_move_assignable<optional<ThrowsMove>>::value, "");
+        struct ThrowsMoveAssign {
+          ThrowsMoveAssign() noexcept {}
+          ThrowsMoveAssign(ThrowsMoveAssign const&) noexcept {}
+          ThrowsMoveAssign(ThrowsMoveAssign &&) noexcept {}
+          ThrowsMoveAssign& operator=(ThrowsMoveAssign const&) noexcept { return *this; }
+          ThrowsMoveAssign& operator=(ThrowsMoveAssign &&) noexcept(false) { return *this; }
+        };
+        static_assert(!std::is_nothrow_move_assignable<optional<ThrowsMoveAssign>>::value, "");
+        struct NoThrowMove {
+          NoThrowMove() noexcept(false) {}
+          NoThrowMove(NoThrowMove const&) noexcept(false) {}
+          NoThrowMove(NoThrowMove &&) noexcept {}
+          NoThrowMove& operator=(NoThrowMove const&) noexcept { return *this; }
+          NoThrowMove& operator=(NoThrowMove&&) noexcept { return *this; }
+        };
+        static_assert(std::is_nothrow_move_assignable<optional<NoThrowMove>>::value, "");
+    }
+}

test/std/utilities/optional/optional.object/optional.object.assign/nullopt_t.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>
+
+// optional<T>& operator=(nullopt_t) noexcept;
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+#include "test_macros.h"
+#include "archetypes.hpp"
+
+using std::optional;
+using std::nullopt_t;
+using std::nullopt;
+
+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);
+    }
+    using TT = TestTypes::TestType;
+    TT::reset();
+    {
+        optional<TT> opt;
+        static_assert(noexcept(opt = nullopt) == true, "");
+        assert(TT::destroyed == 0);
+        opt = nullopt;
+        assert(TT::constructed == 0);
+        assert(TT::alive == 0);
+        assert(TT::destroyed == 0);
+        assert(static_cast<bool>(opt) == false);
+    }
+    assert(TT::alive == 0);
+    assert(TT::destroyed == 0);
+    TT::reset();
+    {
+        optional<TT> opt(42);
+        assert(TT::destroyed == 0);
+        TT::reset_constructors();
+        opt = nullopt;
+        assert(TT::constructed == 0);
+        assert(TT::alive == 0);
+        assert(TT::destroyed == 1);
+        assert(static_cast<bool>(opt) == false);
+    }
+    assert(TT::alive == 0);
+    assert(TT::destroyed == 1);
+    TT::reset();
+}

test/std/utilities/optional/optional.object/optional.object.assign/optional_U.pass.cpp

@@ -0,0 +1,268 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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>
+
+// From LWG2451:
+// template <class U>
+// optional<T>& operator=(optional<U>&& rhs);
+
+#include <optional>
+#include <type_traits>
+#include <memory>
+#include <cassert>
+
+#include "test_macros.h"
+#include "archetypes.hpp"
+
+using std::optional;
+
+struct X
+{
+    static bool throw_now;
+
+    X() = default;
+    X(int &&)
+    {
+        if (throw_now)
+            TEST_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; }
+};
+
+class B {};
+class D : public B {};
+
+
+template <class T>
+struct AssignableFrom {
+  static int type_constructed;
+  static int type_assigned;
+static int int_constructed;
+  static int int_assigned;
+
+  static void reset() {
+      type_constructed = int_constructed = 0;
+      type_assigned = int_assigned = 0;
+  }
+
+  AssignableFrom() = default;
+
+  explicit AssignableFrom(T) { ++type_constructed; }
+  AssignableFrom& operator=(T) { ++type_assigned; return *this; }
+
+  AssignableFrom(int) { ++int_constructed; }
+  AssignableFrom& operator=(int) { ++int_assigned; return *this; }
+private:
+  AssignableFrom(AssignableFrom const&) = delete;
+  AssignableFrom& operator=(AssignableFrom const&) = delete;
+};
+
+template <class T> int AssignableFrom<T>::type_constructed = 0;
+template <class T> int AssignableFrom<T>::type_assigned = 0;
+template <class T> int AssignableFrom<T>::int_constructed = 0;
+template <class T> int AssignableFrom<T>::int_assigned = 0;
+
+void test_with_test_type() {
+    using T = TestTypes::TestType;
+    T::reset();
+    { // non-empty to empty
+        T::reset_constructors();
+        optional<T> opt;
+        optional<int> other(42);
+        opt = std::move(other);
+        assert(T::alive == 1);
+        assert(T::constructed == 1);
+        assert(T::value_constructed == 1);
+        assert(T::assigned == 0);
+        assert(T::destroyed == 0);
+        assert(static_cast<bool>(other) == true);
+        assert(*other == 42);
+        assert(static_cast<bool>(opt) == true);
+        assert(*opt == T(42));
+    }
+    assert(T::alive == 0);
+    { // non-empty to non-empty
+        optional<T> opt(101);
+        optional<int> other(42);
+        T::reset_constructors();
+        opt = std::move(other);
+        assert(T::alive == 1);
+        assert(T::constructed == 0);
+        assert(T::assigned == 1);
+        assert(T::value_assigned == 1);
+        assert(T::destroyed == 0);
+        assert(static_cast<bool>(other) == true);
+        assert(*other == 42);
+        assert(static_cast<bool>(opt) == true);
+        assert(*opt == T(42));
+    }
+    assert(T::alive == 0);
+    { // empty to non-empty
+        optional<T> opt(101);
+        optional<int> other;
+        T::reset_constructors();
+        opt = std::move(other);
+        assert(T::alive == 0);
+        assert(T::constructed == 0);
+        assert(T::assigned == 0);
+        assert(T::destroyed == 1);
+        assert(static_cast<bool>(other) == false);
+        assert(static_cast<bool>(opt) == false);
+    }
+    assert(T::alive == 0);
+    { // empty to empty
+        optional<T> opt;
+        optional<int> other;
+        T::reset_constructors();
+        opt = std::move(other);
+        assert(T::alive == 0);
+        assert(T::constructed == 0);
+        assert(T::assigned == 0);
+        assert(T::destroyed == 0);
+        assert(static_cast<bool>(other) == false);
+        assert(static_cast<bool>(opt) == false);
+    }
+    assert(T::alive == 0);
+}
+
+
+void test_ambigious_assign() {
+    using OptInt = std::optional<int>;
+    {
+        using T = AssignableFrom<OptInt&&>;
+        T::reset();
+        {
+            OptInt a(42);
+            std::optional<T> t;
+            t = std::move(a);
+            assert(T::type_constructed == 1);
+            assert(T::type_assigned == 0);
+            assert(T::int_constructed == 0);
+            assert(T::int_assigned == 0);
+        }
+        {
+            using Opt = std::optional<T>;
+            static_assert(!std::is_assignable<Opt&, const OptInt&&>::value, "");
+            static_assert(!std::is_assignable<Opt&, const OptInt&>::value, "");
+            static_assert(!std::is_assignable<Opt&, OptInt&>::value, "");
+        }
+    }
+    {
+        using T = AssignableFrom<OptInt const&&>;
+        T::reset();
+        {
+            const OptInt a(42);
+            std::optional<T> t;
+            t = std::move(a);
+            assert(T::type_constructed == 1);
+            assert(T::type_assigned == 0);
+            assert(T::int_constructed == 0);
+            assert(T::int_assigned == 0);
+        }
+        T::reset();
+        {
+            OptInt a(42);
+            std::optional<T> t;
+            t = std::move(a);
+            assert(T::type_constructed == 1);
+            assert(T::type_assigned == 0);
+            assert(T::int_constructed == 0);
+            assert(T::int_assigned == 0);
+        }
+        {
+            using Opt = std::optional<T>;
+            static_assert(std::is_assignable<Opt&, OptInt&&>::value, "");
+            static_assert(!std::is_assignable<Opt&, const OptInt&>::value, "");
+            static_assert(!std::is_assignable<Opt&, OptInt&>::value, "");
+        }
+    }
+}
+
+
+int main()
+{
+    test_with_test_type();
+    test_ambigious_assign();
+    {
+        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<std::unique_ptr<B>> opt;
+        optional<std::unique_ptr<D>> other(new D());
+        opt = std::move(other);
+        assert(static_cast<bool>(opt) == true);
+        assert(static_cast<bool>(other) == true);
+        assert(opt->get() != nullptr);
+        assert(other->get() == nullptr);
+    }
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    {
+        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);
+        }
+    }
+#endif
+}

test/std/utilities/optional/optional.object/optional.object.ctor/U.pass.cpp

@@ -0,0 +1,137 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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 EXPLICIT optional(U&& u);
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+#include "test_macros.h"
+#include "archetypes.hpp"
+#include "test_convertible.hpp"
+
+
+using std::optional;
+
+struct ImplicitThrow
+{
+    constexpr ImplicitThrow(int x) { if (x != -1) TEST_THROW(6);}
+};
+
+struct ExplicitThrow
+{
+    constexpr explicit ExplicitThrow(int x) { if (x != -1) TEST_THROW(6);}
+};
+
+
+template <class To, class From>
+constexpr bool implicit_conversion(optional<To>&& opt, const From& v)
+{
+    using O = optional<To>;
+    static_assert(test_convertible<O, From>(), "");
+    static_assert(!test_convertible<O, void*>(), "");
+    static_assert(!test_convertible<O, From, int>(), "");
+    return opt && *opt == static_cast<To>(v);
+}
+
+template <class To, class Input, class Expect>
+constexpr bool explicit_conversion(Input&& in, const Expect& v)
+{
+    using O = optional<To>;
+    static_assert(std::is_constructible<O, Input>::value, "");
+    static_assert(!std::is_convertible<Input, O>::value, "");
+    static_assert(!std::is_constructible<O, void*>::value, "");
+    static_assert(!std::is_constructible<O, Input, int>::value, "");
+    optional<To> opt(std::forward<Input>(in));
+    return opt && *opt == static_cast<To>(v);
+}
+
+void test_implicit()
+{
+    {
+        using T = long long;
+        static_assert(implicit_conversion<long long>(42, 42), "");
+    }
+    {
+        using T = long double;
+        static_assert(implicit_conversion<long double>(3.14, 3.14), "");
+    }
+    {
+        using T = TrivialTestTypes::TestType;
+        static_assert(implicit_conversion<T>(42, 42), "");
+    }
+    {
+        using T = TestTypes::TestType;
+        assert(implicit_conversion<T>(3, T(3)));
+    }
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    {
+        try {
+            using T = ImplicitThrow;
+            optional<T> t = 42;
+            assert(false);
+        } catch (int) {
+        }
+    }
+#endif
+}
+
+void test_explicit() {
+    {
+        using T = ExplicitTrivialTestTypes::TestType;
+        using O = optional<T>;
+        static_assert(explicit_conversion<T>(42, 42), "");
+    }
+    {
+        using T = ExplicitConstexprTestTypes::TestType;
+        using O = optional<T>;
+        static_assert(explicit_conversion<T>(42, 42), "");
+        static_assert(!std::is_convertible<int, T>::value, "");
+    }
+    {
+        using T = ExplicitTestTypes::TestType;
+        using O = optional<T>;
+        T::reset();
+        {
+            assert(explicit_conversion<T>(42, 42));
+            assert(T::alive == 0);
+        }
+        T::reset();
+        {
+            optional<T> t(42);
+            assert(T::alive == 1);
+            assert(T::value_constructed == 1);
+            assert(T::move_constructed == 0);
+            assert(T::copy_constructed == 0);
+            assert(t.value().value == 42);
+        }
+        assert(T::alive == 0);
+    }
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    {
+        try {
+            using T = ExplicitThrow;
+            optional<T> t(42);
+            assert(false);
+        } catch (int) {
+        }
+    }
+#endif
+}
+
+int main() {
+    test_implicit();
+    test_explicit();
+}

test/std/utilities/optional/optional.object/optional.object.ctor/const_T.pass.cpp

@@ -0,0 +1,123 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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(const T& v);
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+#include "test_macros.h"
+#include "archetypes.hpp"
+
+using std::optional;
+
+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 TestTypes::TestType T;
+        T::reset();
+        const T t(3);
+        optional<T> opt = t;
+        assert(T::alive == 2);
+        assert(T::copy_constructed == 1);
+        assert(static_cast<bool>(opt) == true);
+        assert(opt.value().value == 3);
+    }
+    {
+        typedef ExplicitTestTypes::TestType T;
+        static_assert(!std::is_convertible<T const&, optional<T>>::value, "");
+        T::reset();
+        const T t(3);
+        optional<T> opt(t);
+        assert(T::alive == 2);
+        assert(T::copy_constructed == 1);
+        assert(static_cast<bool>(opt) == true);
+        assert(opt.value().value == 3);
+    }
+    {
+        typedef ConstexprTestTypes::TestType T;
+        constexpr T t(3);
+        constexpr optional<T> opt = {t};
+        static_assert(static_cast<bool>(opt) == true, "");
+        static_assert(opt.value().value == 3, "");
+
+        struct test_constexpr_ctor
+            : public optional<T>
+        {
+            constexpr test_constexpr_ctor(const T&) {}
+        };
+    }
+    {
+        typedef ExplicitConstexprTestTypes::TestType T;
+        static_assert(!std::is_convertible<const T&, optional<T>>::value, "");
+        constexpr T t(3);
+        constexpr optional<T> opt(t);
+        static_assert(static_cast<bool>(opt) == true, "");
+        static_assert(opt.value().value == 3, "");
+
+        struct test_constexpr_ctor
+            : public optional<T>
+        {
+            constexpr test_constexpr_ctor(const T&) {}
+        };
+
+    }
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    {
+        struct Z {
+            Z(int) {}
+            Z(const Z&) {throw 6;}
+        };
+        typedef Z T;
+        try
+        {
+            const T t(3);
+            optional<T> opt(t);
+            assert(false);
+        }
+        catch (int i)
+        {
+            assert(i == 6);
+        }
+    }
+#endif
+}

test/std/utilities/optional/optional.object/optional.object.ctor/const_optional_U.pass.cpp

@@ -0,0 +1,134 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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(const optional<U>& rhs);
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+#include "test_macros.h"
+
+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);
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    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);
+    }
+#else
+    if (is_going_to_throw) return;
+    optional<T> lhs = rhs;
+    assert(static_cast<bool>(lhs) == rhs_engaged);
+    if (rhs_engaged)
+        assert(*lhs == *rhs);
+#endif
+}
+
+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) {TEST_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), "");
+}

test/std/utilities/optional/optional.object/optional.object.ctor/copy.pass.cpp

@@ -0,0 +1,150 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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(const optional<T>& rhs);
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+#include "test_macros.h"
+#include "archetypes.hpp"
+
+using std::optional;
+
+template <class T, class ...InitArgs>
+void test(InitArgs&&... args)
+{
+    const optional<T> rhs(std::forward<InitArgs>(args)...);
+    bool rhs_engaged = static_cast<bool>(rhs);
+    optional<T> lhs = rhs;
+    assert(static_cast<bool>(lhs) == rhs_engaged);
+    if (rhs_engaged)
+        assert(*lhs == *rhs);
+}
+
+void test_throwing_ctor() {
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    struct Z {
+      Z() : count(0) {}
+      Z(Z const& o) : count(o.count + 1)
+      { if (count == 2) throw 6; }
+      int count;
+    };
+    const Z z;
+    const optional<Z> rhs(z);
+    try
+    {
+        optional<Z> lhs(rhs);
+        assert(false);
+    }
+    catch (int i)
+    {
+        assert(i == 6);
+    }
+#endif
+}
+
+template <class T, class ...InitArgs>
+void test_ref(InitArgs&&... args)
+{
+    const optional<T> rhs(std::forward<InitArgs>(args)...);
+    bool rhs_engaged = static_cast<bool>(rhs);
+    optional<T> lhs = rhs;
+    assert(static_cast<bool>(lhs) == rhs_engaged);
+    if (rhs_engaged)
+        assert(&(*lhs) == &(*rhs));
+}
+
+
+void test_reference_extension()
+{
+#if defined(_LIBCPP_VERSION) && 0 // FIXME these extensions are currently disabled.
+    using T = TestTypes::TestType;
+    T::reset();
+    {
+        T t;
+        T::reset_constructors();
+        test_ref<T&>();
+        test_ref<T&>(t);
+        assert(T::alive == 1);
+        assert(T::constructed == 0);
+        assert(T::assigned == 0);
+        assert(T::destroyed == 0);
+    }
+    assert(T::destroyed == 1);
+    assert(T::alive == 0);
+    {
+        T t;
+        const T& ct = t;
+        T::reset_constructors();
+        test_ref<T const&>();
+        test_ref<T const&>(t);
+        test_ref<T const&>(ct);
+        assert(T::alive == 1);
+        assert(T::constructed == 0);
+        assert(T::assigned == 0);
+        assert(T::destroyed == 0);
+    }
+    assert(T::alive == 0);
+    assert(T::destroyed == 1);
+    {
+        static_assert(!std::is_copy_constructible<std::optional<T&&>>::value, "");
+        static_assert(!std::is_copy_constructible<std::optional<T const&&>>::value, "");
+    }
+#endif
+}
+
+int main()
+{
+    test<int>();
+    test<int>(3);
+    {
+        using T = TestTypes::TestType;
+        T::reset();
+        const optional<T> rhs;
+        assert(T::alive == 0);
+        const optional<T> lhs(rhs);
+        assert(lhs.has_value() == false);
+        assert(T::alive == 0);
+    }
+    TestTypes::TestType::reset();
+    {
+        using T = TestTypes::TestType;
+        T::reset();
+        const optional<T> rhs(42);
+        assert(T::alive == 1);
+        assert(T::value_constructed == 1);
+        assert(T::copy_constructed == 0);
+        const optional<T> lhs(rhs);
+        assert(lhs.has_value());
+        assert(T::copy_constructed == 1);
+        assert(T::alive == 2);
+    }
+    TestTypes::TestType::reset();
+    {
+        using namespace ConstexprTestTypes;
+        test<TestType>();
+        test<TestType>(42);
+    }
+    {
+        using namespace TrivialTestTypes;
+        test<TestType>();
+        test<TestType>(42);
+    }
+    {
+        test_throwing_ctor();
+    }
+    {
+        test_reference_extension();
+    }
+}

test/std/utilities/optional/optional.object/optional.object.ctor/default.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
+// <optional>
+
+// constexpr optional() noexcept;
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+#include "test_macros.h"
+#include "archetypes.hpp"
+
+using std::optional;
+
+template <class Opt>
+void
+test_constexpr()
+{
+    static_assert(std::is_nothrow_default_constructible<Opt>::value, "");
+    static_assert(std::is_trivially_destructible<Opt>::value, "");
+    static_assert(std::is_trivially_destructible<typename Opt::value_type>::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, "");
+    static_assert(!std::is_trivially_destructible<Opt>::value, "");
+    static_assert(!std::is_trivially_destructible<typename Opt::value_type>::value, "");
+    {
+        Opt opt;
+        assert(static_cast<bool>(opt) == false);
+    }
+    {
+        const Opt opt;
+        assert(static_cast<bool>(opt) == false);
+    }
+
+    struct test_constexpr_ctor
+        : public Opt
+    {
+        constexpr test_constexpr_ctor() {}
+    };
+}
+
+int main()
+{
+    test_constexpr<optional<int>>();
+    test_constexpr<optional<int*>>();
+    test_constexpr<optional<ImplicitTypes::NoCtors>>();
+    test_constexpr<optional<NonTrivialTypes::NoCtors>>();
+    test_constexpr<optional<NonConstexprTypes::NoCtors>>();
+    test<optional<NonLiteralTypes::NoCtors>>();
+    // EXTENSIONS
+#if defined(_LIBCPP_VERSION) && 0 // FIXME these extensions are currently disabled.
+    test_constexpr<optional<int&>>();
+    test_constexpr<optional<const int&>>();
+    test_constexpr<optional<int&>>();
+    test_constexpr<optional<NonLiteralTypes::NoCtors&>>();
+    test_constexpr<optional<NonLiteralTypes::NoCtors&&>>();
+#endif
+}

test/std/utilities/optional/optional.object/optional.object.ctor/explicit_const_optional_U.pass.cpp

@@ -0,0 +1,121 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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>
+//   explicit optional(const optional<U>& rhs);
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+#include "test_macros.h"
+
+using std::optional;
+
+template <class T, class U>
+void
+test(const optional<U>& rhs, bool is_going_to_throw = false)
+{
+    static_assert(!(std::is_convertible<const optional<U>&, optional<T>>::value), "");
+    bool rhs_engaged = static_cast<bool>(rhs);
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    try
+    {
+        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);
+    }
+#else
+    if (is_going_to_throw) return;
+    optional<T> lhs(rhs);
+    assert(static_cast<bool>(lhs) == rhs_engaged);
+    if (rhs_engaged)
+        assert(*lhs == T(*rhs));
+#endif
+}
+
+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) { TEST_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);
+    }
+}

test/std/utilities/optional/optional.object/optional.object.ctor/explicit_optional_U.pass.cpp

@@ -0,0 +1,84 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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>
+//   explicit optional(optional<U>&& rhs);
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+#include "test_macros.h"
+
+using std::optional;
+
+template <class T, class U>
+void
+test(optional<U>&& rhs, bool is_going_to_throw = false)
+{
+    static_assert(!(std::is_convertible<optional<U>&&, optional<T>>::value), "");
+    bool rhs_engaged = static_cast<bool>(rhs);
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    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);
+    }
+#else
+    if (is_going_to_throw) return;
+    optional<T> lhs(std::move(rhs));
+    assert(static_cast<bool>(lhs) == rhs_engaged);
+#endif
+}
+
+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) { TEST_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);
+    }
+}

test/std/utilities/optional/optional.object/optional.object.ctor/in_place_t.pass.cpp

@@ -0,0 +1,144 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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... Args>
+//   constexpr explicit optional(in_place_t, Args&&... args);
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+#include "test_macros.h"
+
+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) {TEST_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) {}
+        };
+
+    }
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    {
+        try
+        {
+            const optional<Z> opt(in_place, 1);
+            assert(false);
+        }
+        catch (int i)
+        {
+            assert(i == 6);
+        }
+    }
+#endif
+}

test/std/utilities/optional/optional.object/optional.object.ctor/initializer_list.pass.cpp

@@ -0,0 +1,116 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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, class... Args>
+//     constexpr
+//     explicit optional(in_place_t, initializer_list<U> il, Args&&... args);
+
+#include <optional>
+#include <type_traits>
+#include <vector>
+#include <cassert>
+
+#include "test_macros.h"
+
+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])
+        {TEST_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) {}
+        };
+
+    }
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    {
+        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);
+        }
+    }
+#endif
+}

test/std/utilities/optional/optional.object/optional.object.ctor/move.pass.cpp

@@ -0,0 +1,196 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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(optional<T>&& rhs);
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+#include "test_macros.h"
+#include "archetypes.hpp"
+
+using std::optional;
+
+template <class T, class ...InitArgs>
+void test(InitArgs&&... args)
+{
+    const optional<T> orig(std::forward<InitArgs>(args)...);
+    optional<T> rhs(orig);
+    bool rhs_engaged = static_cast<bool>(rhs);
+    optional<T> lhs = std::move(rhs);
+    assert(static_cast<bool>(lhs) == rhs_engaged);
+    if (rhs_engaged)
+        assert(*lhs == *orig);
+}
+
+void test_throwing_ctor() {
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    struct Z {
+      Z() : count(0) {}
+      Z(Z&& o) : count(o.count + 1)
+      { if (count == 2) throw 6; }
+      int count;
+    };
+    Z z;
+    optional<Z> rhs(std::move(z));
+    try
+    {
+        optional<Z> lhs(std::move(rhs));
+        assert(false);
+    }
+    catch (int i)
+    {
+        assert(i == 6);
+    }
+#endif
+}
+
+
+template <class T, class ...InitArgs>
+void test_ref(InitArgs&&... args)
+{
+    optional<T> rhs(std::forward<InitArgs>(args)...);
+    bool rhs_engaged = static_cast<bool>(rhs);
+    optional<T> lhs = std::move(rhs);
+    assert(static_cast<bool>(lhs) == rhs_engaged);
+    if (rhs_engaged)
+        assert(&(*lhs) == &(*rhs));
+}
+
+void test_reference_extension()
+{
+#if defined(_LIBCPP_VERSION) && 0 // FIXME these extensions are currently disabled.
+    using T = TestTypes::TestType;
+    T::reset();
+    {
+        T t;
+        T::reset_constructors();
+        test_ref<T&>();
+        test_ref<T&>(t);
+        assert(T::alive == 1);
+        assert(T::constructed == 0);
+        assert(T::assigned == 0);
+        assert(T::destroyed == 0);
+    }
+    assert(T::destroyed == 1);
+    assert(T::alive == 0);
+    {
+        T t;
+        const T& ct = t;
+        T::reset_constructors();
+        test_ref<T const&>();
+        test_ref<T const&>(t);
+        test_ref<T const&>(ct);
+        assert(T::alive == 1);
+        assert(T::constructed == 0);
+        assert(T::assigned == 0);
+        assert(T::destroyed == 0);
+    }
+    assert(T::alive == 0);
+    assert(T::destroyed == 1);
+    {
+        T t;
+        T::reset_constructors();
+        test_ref<T&&>();
+        test_ref<T&&>(std::move(t));
+        assert(T::alive == 1);
+        assert(T::constructed == 0);
+        assert(T::assigned == 0);
+        assert(T::destroyed == 0);
+    }
+    assert(T::alive == 0);
+    assert(T::destroyed == 1);
+    {
+        T t;
+        const T& ct = t;
+        T::reset_constructors();
+        test_ref<T const&&>();
+        test_ref<T const&&>(std::move(t));
+        test_ref<T const&&>(std::move(ct));
+        assert(T::alive == 1);
+        assert(T::constructed == 0);
+        assert(T::assigned == 0);
+        assert(T::destroyed == 0);
+    }
+    assert(T::alive == 0);
+    assert(T::destroyed == 1);
+    {
+        static_assert(!std::is_copy_constructible<std::optional<T&&>>::value, "");
+        static_assert(!std::is_copy_constructible<std::optional<T const&&>>::value, "");
+    }
+#endif
+}
+
+
+int main()
+{
+    test<int>();
+    test<int>(3);
+    {
+        using T = TestTypes::TestType;
+        T::reset();
+        optional<T> rhs;
+        assert(T::alive == 0);
+        const optional<T> lhs(std::move(rhs));
+        assert(lhs.has_value() == false);
+        assert(rhs.has_value() == false);
+        assert(T::alive == 0);
+    }
+    TestTypes::TestType::reset();
+    {
+        using T = TestTypes::TestType;
+        T::reset();
+        optional<T> rhs(42);
+        assert(T::alive == 1);
+        assert(T::value_constructed == 1);
+        assert(T::move_constructed == 0);
+        const optional<T> lhs(std::move(rhs));
+        assert(lhs.has_value());
+        assert(rhs.has_value());
+        assert(lhs.value().value == 42);
+        assert(rhs.value().value == -1);
+        assert(T::move_constructed == 1);
+        assert(T::alive == 2);
+    }
+    TestTypes::TestType::reset();
+    {
+        using namespace ConstexprTestTypes;
+        test<TestType>();
+        test<TestType>(42);
+    }
+    {
+        using namespace TrivialTestTypes;
+        test<TestType>();
+        test<TestType>(42);
+    }
+    {
+        test_throwing_ctor();
+    }
+    {
+        struct ThrowsMove {
+          ThrowsMove() noexcept(false) {}
+          ThrowsMove(ThrowsMove const&) noexcept(false) {}
+          ThrowsMove(ThrowsMove &&) noexcept(false) {}
+        };
+        static_assert(!std::is_nothrow_move_constructible<optional<ThrowsMove>>::value, "");
+        struct NoThrowMove {
+          NoThrowMove() noexcept(false) {}
+          NoThrowMove(NoThrowMove const&) noexcept(false) {}
+          NoThrowMove(NoThrowMove &&) noexcept(true) {}
+        };
+        static_assert(std::is_nothrow_move_constructible<optional<NoThrowMove>>::value, "");
+    }
+    {
+        test_reference_extension();
+    }
+}

test/std/utilities/optional/optional.object/optional.object.ctor/nullopt_t.pass.cpp

@@ -0,0 +1,73 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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>
+
+#include "archetypes.hpp"
+
+using std::optional;
+using std::nullopt_t;
+using std::nullopt;
+
+template <class Opt>
+void
+test_constexpr()
+{
+    static_assert(std::is_nothrow_constructible<Opt, nullopt_t&>::value, "");
+    static_assert(std::is_trivially_destructible<Opt>::value, "");
+    static_assert(std::is_trivially_destructible<typename Opt::value_type>::value, "");
+
+    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(std::is_nothrow_constructible<Opt, nullopt_t&>::value, "");
+    static_assert(!std::is_trivially_destructible<Opt>::value, "");
+    static_assert(!std::is_trivially_destructible<typename Opt::value_type>::value, "");
+    {
+    Opt opt(nullopt);
+    assert(static_cast<bool>(opt) == false);
+    }
+    {
+    const Opt opt(nullopt);
+    assert(static_cast<bool>(opt) == false);
+    }
+    struct test_constexpr_ctor
+        : public Opt
+    {
+        constexpr test_constexpr_ctor() {}
+    };
+}
+
+int main()
+{
+    test_constexpr<optional<int>>();
+    test_constexpr<optional<int*>>();
+    test_constexpr<optional<ImplicitTypes::NoCtors>>();
+    test_constexpr<optional<NonTrivialTypes::NoCtors>>();
+    test_constexpr<optional<NonConstexprTypes::NoCtors>>();
+    test<optional<NonLiteralTypes::NoCtors>>();
+}

test/std/utilities/optional/optional.object/optional.object.ctor/optional_U.pass.cpp

@@ -0,0 +1,93 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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(optional<U>&& rhs);
+
+#include <optional>
+#include <type_traits>
+#include <memory>
+#include <cassert>
+
+#include "test_macros.h"
+
+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);
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    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);
+    }
+#else
+    if (is_going_to_throw) return;
+    optional<T> lhs = std::move(rhs);
+    assert(static_cast<bool>(lhs) == rhs_engaged);
+#endif
+}
+
+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) { TEST_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), "");
+}

test/std/utilities/optional/optional.object/optional.object.ctor/rvalue_T.pass.cpp

@@ -0,0 +1,148 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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(T&& v);
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+#include "test_macros.h"
+#include "archetypes.hpp"
+
+
+using std::optional;
+
+
+class Z
+{
+public:
+    Z(int) {}
+    Z(Z&&) {TEST_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 TestTypes::TestType T;
+        T::reset();
+        optional<T> opt = T{3};
+        assert(T::alive == 1);
+        assert(T::move_constructed == 1);
+        assert(static_cast<bool>(opt) == true);
+        assert(opt.value().value == 3);
+    }
+    {
+        typedef ExplicitTestTypes::TestType T;
+        static_assert(!std::is_convertible<T&&, optional<T>>::value, "");
+        T::reset();
+        optional<T> opt(T{3});
+        assert(T::alive == 1);
+        assert(T::move_constructed == 1);
+        assert(static_cast<bool>(opt) == true);
+        assert(opt.value().value == 3);
+    }
+    {
+        typedef TestTypes::TestType T;
+        T::reset();
+        optional<T> opt = {3};
+        assert(T::alive == 1);
+        assert(T::value_constructed == 1);
+        assert(T::copy_constructed == 0);
+        assert(T::move_constructed == 0);
+        assert(static_cast<bool>(opt) == true);
+        assert(opt.value().value == 3);
+    }
+    {
+        typedef ConstexprTestTypes::TestType T;
+        constexpr optional<T> opt = {T(3)};
+        static_assert(static_cast<bool>(opt) == true, "");
+        static_assert(opt.value().value == 3, "");
+
+        struct test_constexpr_ctor
+            : public optional<T>
+        {
+            constexpr test_constexpr_ctor(const T&) {}
+        };
+    }
+    {
+        typedef ConstexprTestTypes::TestType T;
+        constexpr optional<T> opt = {3};
+        static_assert(static_cast<bool>(opt) == true, "");
+        static_assert(opt.value().value == 3, "");
+
+        struct test_constexpr_ctor
+            : public optional<T>
+        {
+            constexpr test_constexpr_ctor(const T&) {}
+        };
+    }
+    {
+        typedef ExplicitConstexprTestTypes::TestType T;
+        static_assert(!std::is_convertible<T&&, optional<T>>::value, "");
+        constexpr optional<T> opt(T{3});
+        static_assert(static_cast<bool>(opt) == true, "");
+        static_assert(opt.value().value == 3, "");
+
+        struct test_constexpr_ctor
+            : public optional<T>
+        {
+            constexpr test_constexpr_ctor(T&&) {}
+        };
+
+    }
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    {
+        struct Z {
+            Z(int) {}
+            Z(Z&&) {throw 6;}
+        };
+        typedef Z T;
+        try
+        {
+            T t(3);
+            optional<T> opt(std::move(t));
+            assert(false);
+        }
+        catch (int i)
+        {
+            assert(i == 6);
+        }
+    }
+#endif
+}

test/std/utilities/optional/optional.object/optional.object.dtor/dtor.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
+// <optional>
+
+// ~optional();
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+using std::optional;
+
+struct PODType {
+  int value;
+  int value2;
+};
+
+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, "");
+        static_assert(std::is_literal_type<optional<T>>::value, "");
+    }
+    {
+        typedef double T;
+        static_assert(std::is_trivially_destructible<T>::value, "");
+        static_assert(std::is_trivially_destructible<optional<T>>::value, "");
+        static_assert(std::is_literal_type<optional<T>>::value, "");
+    }
+    {
+        typedef PODType T;
+        static_assert(std::is_trivially_destructible<T>::value, "");
+        static_assert(std::is_trivially_destructible<optional<T>>::value, "");
+        static_assert(std::is_literal_type<optional<T>>::value, "");
+    }
+    {
+        typedef X T;
+        static_assert(!std::is_trivially_destructible<T>::value, "");
+        static_assert(!std::is_trivially_destructible<optional<T>>::value, "");
+        static_assert(!std::is_literal_type<optional<T>>::value, "");
+        {
+            X x;
+            optional<X> opt{x};
+            assert(X::dtor_called == false);
+        }
+        assert(X::dtor_called == true);
+    }
+}

test/std/utilities/optional/optional.object/optional.object.mod/reset.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>
+
+// 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
+    {
+        optional<X> opt(X{});
+        X::dtor_called = false;
+        opt.reset();
+        assert(X::dtor_called == true);
+        assert(static_cast<bool>(opt) == false);
+        X::dtor_called = false;
+    }
+    assert(X::dtor_called == false); // TRANSITION, Clang/C2 VSO#239997
+}

test/std/utilities/optional/optional.object/optional.object.observe/bool.pass.cpp

@@ -0,0 +1,37 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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>
+
+#include "test_macros.h"
+
+int main()
+{
+    using std::optional;
+    {
+        const optional<int> opt; ((void)opt);
+        ASSERT_NOEXCEPT(bool(opt));
+        static_assert(!std::is_convertible<optional<int>, bool>::value, "");
+    }
+    {
+        constexpr optional<int> opt;
+        static_assert(!opt, "");
+    }
+    {
+        constexpr optional<int> opt(0);
+        static_assert(opt, "");
+    }
+}

test/std/utilities/optional/optional.object/optional.object.observe/dereference.pass.cpp

@@ -0,0 +1,73 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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>
+
+#include "test_macros.h"
+
+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
+{
+    constexpr int test() {return 7;}
+};
+
+constexpr int
+test()
+{
+    optional<Y> opt{Y{}};
+    return (*opt).test();
+}
+
+int main()
+{
+    {
+        optional<X> opt; ((void)opt);
+        ASSERT_SAME_TYPE(decltype(*opt), X&);
+        // ASSERT_NOT_NOEXCEPT(*opt);
+        // FIXME: This assertion fails with GCC because it can see that
+        // (A) operator*() is constexpr, and
+        // (B) there is no path through the function that throws.
+        // It's arguable if this is the correct behavior for the noexcept
+        // operator.
+        // Regardless this function should still be noexcept(false) because
+        // it has a narrow contract.
+    }
+    {
+        optional<X> opt(X{});
+        assert((*opt).test() == 4);
+    }
+    static_assert(test() == 7, "");
+#ifdef _LIBCPP_DEBUG
+    {
+        optional<X> opt;
+        assert((*opt).test() == 3);
+        assert(false);
+    }
+#endif  // _LIBCPP_DEBUG
+}

test/std/utilities/optional/optional.object/optional.object.observe/dereference_const.pass.cpp

@@ -0,0 +1,69 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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>
+
+#include "test_macros.h"
+
+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()
+{
+    {
+        const optional<X> opt; ((void)opt);
+        ASSERT_SAME_TYPE(decltype(*opt), X const&);
+        // ASSERT_NOT_NOEXCEPT(*opt);
+        // FIXME: This assertion fails with GCC because it can see that
+        // (A) operator*() is constexpr, and
+        // (B) there is no path through the function that throws.
+        // It's arguable if this is the correct behavior for the noexcept
+        // operator.
+        // Regardless this function should still be noexcept(false) because
+        // it has a narrow contract.
+    }
+    {
+        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
+}

test/std/utilities/optional/optional.object/optional.object.observe/dereference_const_rvalue.pass.cpp

@@ -0,0 +1,69 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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>
+
+#include "test_macros.h"
+
+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()
+{
+    {
+        const optional<X> opt; ((void)opt);
+        ASSERT_SAME_TYPE(decltype(*std::move(opt)), X const &&);
+        // ASSERT_NOT_NOEXCEPT(*std::move(opt));
+        // FIXME: This assertion fails with GCC because it can see that
+        // (A) operator*() is constexpr, and
+        // (B) there is no path through the function that throws.
+        // It's arguable if this is the correct behavior for the noexcept
+        // operator.
+        // Regardless this function should still be noexcept(false) because
+        // it has a narrow contract.
+    }
+    {
+        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
+}

test/std/utilities/optional/optional.object/optional.object.observe/dereference_rvalue.pass.cpp

@@ -0,0 +1,73 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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>
+
+#include "test_macros.h"
+
+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
+{
+    constexpr int test() && {return 7;}
+};
+
+constexpr int
+test()
+{
+    optional<Y> opt{Y{}};
+    return (*std::move(opt)).test();
+}
+
+int main()
+{
+    {
+        optional<X> opt; ((void)opt);
+        ASSERT_SAME_TYPE(decltype(*std::move(opt)), X&&);
+        // ASSERT_NOT_NOEXCEPT(*std::move(opt));
+        // FIXME: This assertion fails with GCC because it can see that
+        // (A) operator*() is constexpr, and
+        // (B) there is no path through the function that throws.
+        // It's arguable if this is the correct behavior for the noexcept
+        // operator.
+        // Regardless this function should still be noexcept(false) because
+        // it has a narrow contract.
+    }
+    {
+        optional<X> opt(X{});
+        assert((*std::move(opt)).test() == 6);
+    }
+    static_assert(test() == 7, "");
+#ifdef _LIBCPP_DEBUG
+    {
+        optional<X> opt;
+        assert((*std::move(opt)).test() == 3);
+        assert(false);
+    }
+#endif  // _LIBCPP_DEBUG
+}

test/std/utilities/optional/optional.object/optional.object.observe/has_value.pass.cpp

@@ -0,0 +1,37 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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>
+
+#include "test_macros.h"
+
+int main()
+{
+    using std::optional;
+    {
+        const optional<int> opt; ((void)opt);
+        ASSERT_NOEXCEPT(opt.has_value());
+        ASSERT_SAME_TYPE(decltype(opt.has_value()), bool);
+    }
+    {
+        constexpr optional<int> opt;
+        static_assert(!opt.has_value(), "");
+    }
+    {
+        constexpr optional<int> opt(0);
+        static_assert(opt.has_value(), "");
+    }
+}

test/std/utilities/optional/optional.object/optional.object.observe/op_arrow.pass.cpp

@@ -0,0 +1,72 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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>
+
+#include "test_macros.h"
+
+using std::optional;
+
+struct X
+{
+    int test() noexcept {return 3;}
+};
+
+struct Y
+{
+    constexpr int test() {return 3;}
+};
+
+constexpr int
+test()
+{
+    optional<Y> opt{Y{}};
+    return opt->test();
+}
+
+int main()
+{
+    {
+        std::optional<X> opt; ((void)opt);
+        ASSERT_SAME_TYPE(decltype(opt.operator->()), X*);
+        // ASSERT_NOT_NOEXCEPT(opt.operator->());
+        // FIXME: This assertion fails with GCC because it can see that
+        // (A) operator->() is constexpr, and
+        // (B) there is no path through the function that throws.
+        // It's arguable if this is the correct behavior for the noexcept
+        // operator.
+        // Regardless this function should still be noexcept(false) because
+        // it has a narrow contract.
+    }
+    {
+        optional<X> opt(X{});
+        assert(opt->test() == 3);
+    }
+    {
+        static_assert(test() == 3, "");
+    }
+#ifdef _LIBCPP_DEBUG
+    {
+        optional<X> opt;
+        assert(opt->test() == 3);
+        assert(false);
+    }
+#endif  // _LIBCPP_DEBUG
+}

test/std/utilities/optional/optional.object/optional.object.observe/op_arrow_const.pass.cpp

@@ -0,0 +1,76 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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>
+
+#include "test_macros.h"
+
+using std::optional;
+
+struct X
+{
+    constexpr int test() const {return 3;}
+};
+
+struct Y
+{
+    int test() const noexcept {return 2;}
+};
+
+struct Z
+{
+    const Z* operator&() const;
+    constexpr int test() const {return 1;}
+};
+
+int main()
+{
+    {
+        const std::optional<X> opt; ((void)opt);
+        ASSERT_SAME_TYPE(decltype(opt.operator->()), X const*);
+        // ASSERT_NOT_NOEXCEPT(opt.operator->());
+        // FIXME: This assertion fails with GCC because it can see that
+        // (A) operator->() is constexpr, and
+        // (B) there is no path through the function that throws.
+        // It's arguable if this is the correct behavior for the noexcept
+        // operator.
+        // Regardless this function should still be noexcept(false) because
+        // it has a narrow contract.
+    }
+    {
+        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
+}

test/std/utilities/optional/optional.object/optional.object.observe/value.pass.cpp

@@ -0,0 +1,73 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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>::value() &;
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+#include "test_macros.h"
+
+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;}
+};
+
+struct Y
+{
+    constexpr int test() & {return 7;}
+};
+
+constexpr int
+test()
+{
+    optional<Y> opt{Y{}};
+    return opt.value().test();
+}
+
+
+int main()
+{
+    {
+        optional<X> opt; ((void)opt);
+        ASSERT_NOT_NOEXCEPT(opt.value());
+        ASSERT_SAME_TYPE(decltype(opt.value()), X&);
+    }
+    {
+        optional<X> opt;
+        opt.emplace();
+        assert(opt.value().test() == 4);
+    }
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    {
+        optional<X> opt;
+        try
+        {
+            opt.value();
+            assert(false);
+        }
+        catch (const bad_optional_access&)
+        {
+        }
+    }
+#endif
+    static_assert(test() == 7, "");
+}

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, "");
+    }
+}

test/std/utilities/optional/optional.object/optional.object.observe/value_const.pass.cpp

@@ -0,0 +1,64 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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>
+
+#include "test_macros.h"
+
+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()
+{
+    {
+        const optional<X> opt; ((void)opt);
+        ASSERT_NOT_NOEXCEPT(opt.value());
+        ASSERT_SAME_TYPE(decltype(opt.value()), X const&);
+    }
+    {
+        constexpr optional<X> opt(in_place);
+        static_assert(opt.value().test() == 3, "");
+    }
+    {
+        const optional<X> opt(in_place);
+        assert(opt.value().test() == 3);
+    }
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    {
+        const optional<X> opt;
+        try
+        {
+            opt.value();
+            assert(false);
+        }
+        catch (const bad_optional_access&)
+        {
+        }
+    }
+#endif
+}

test/std/utilities/optional/optional.object/optional.object.observe/value_const_rvalue.pass.cpp

@@ -0,0 +1,64 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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>
+
+#include "test_macros.h"
+
+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()
+{
+    {
+        const optional<X> opt; ((void)opt);
+        ASSERT_NOT_NOEXCEPT(std::move(opt).value());
+        ASSERT_SAME_TYPE(decltype(std::move(opt).value()), X const&&);
+    }
+    {
+        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);
+    }
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    {
+        const optional<X> opt;
+        try
+        {
+            std::move(opt).value();
+            assert(false);
+        }
+        catch (const bad_optional_access&)
+        {
+        }
+    }
+#endif
+}

test/std/utilities/optional/optional.object/optional.object.observe/value_or.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
+// <optional>
+
+// template <class U> T optional<T>::value_or(U&& v) &&;
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+#include "test_macros.h"
+
+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);
+    }
+}

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);
+    }
+}

test/std/utilities/optional/optional.object/optional.object.observe/value_rvalue.pass.cpp

@@ -0,0 +1,72 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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>::value() &&;
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+#include "test_macros.h"
+
+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;}
+};
+
+struct Y
+{
+    constexpr int test() && {return 7;}
+};
+
+constexpr int
+test()
+{
+    optional<Y> opt{Y{}};
+    return std::move(opt).value().test();
+}
+
+int main()
+{
+    {
+        optional<X> opt; ((void)opt);
+        ASSERT_NOT_NOEXCEPT(std::move(opt).value());
+        ASSERT_SAME_TYPE(decltype(std::move(opt).value()), X&&);
+    }
+    {
+        optional<X> opt;
+        opt.emplace();
+        assert(std::move(opt).value().test() == 6);
+    }
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    {
+        optional<X> opt;
+        try
+        {
+            std::move(opt).value();
+            assert(false);
+        }
+        catch (const bad_optional_access&)
+        {
+        }
+    }
+#endif
+    static_assert(test() == 7, "");
+}

test/std/utilities/optional/optional.object/optional.object.swap/swap.pass.cpp

@@ -0,0 +1,306 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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 swap(optional&)
+//     noexcept(is_nothrow_move_constructible<T>::value &&
+//              is_nothrow_swappable<T>::value)
+
+#include <optional>
+#include <type_traits>
+#include <cassert>
+
+#include "test_macros.h"
+#include "archetypes.hpp"
+
+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&&) {TEST_THROW(7);}
+
+    friend constexpr bool operator==(const Z& x, const Z& y) {return x.i_ == y.i_;}
+    friend void swap(Z& x, Z& y) {TEST_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);
+    }
+#ifndef TEST_HAS_NO_EXCEPTIONS
+    {
+        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);
+    }
+#endif
+}

test/std/utilities/optional/optional.object/optional_requires_destructible_object.fail.cpp

@@ -0,0 +1,50 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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()
+{
+    using std::optional;
+    {
+        // expected-error@optional:* 2 {{static_assert failed "instantiation of optional with a reference type is ill-formed}}
+        optional<int&> opt1;
+        optional<int&&> opt2;
+    }
+    {
+        // expected-error@optional:* {{static_assert failed "instantiation of optional with a non-destructible type is ill-formed"}}
+        optional<X> opt3;
+    }
+    {
+        // expected-error@optional:* {{static_assert failed "instantiation of optional with a non-object type is undefined behavior"}}
+        // expected-error@optional:* {{static_assert failed "instantiation of optional with a non-destructible type is ill-formed}}
+        optional<void()> opt4;
+    }
+    {
+        // expected-error@optional:* {{static_assert failed "instantiation of optional with a non-object type is undefined behavior"}}
+        // expected-error@optional:* {{static_assert failed "instantiation of optional with a non-destructible type is ill-formed}}
+        // expected-error@optional:* 1+ {{cannot form a reference to 'void'}}
+        optional<const void> opt4;
+    }
+    // FIXME these are garbage diagnostics that Clang should not produce
+    // expected-error@optional:* 0+ {{is not a base class}}
+}

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>{}
+    );
+}

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>();
+}