vendor/libc++/libc++-release_370-r246257

8 files changed, 881 insertions, 0 deletions

diff --git a/test/std/experimental/optional/optional.object/optional.object.ctor/const_T.pass.cpp b/test/std/experimental/optional/optional.object/optional.object.ctor/const_T.pass.cpp
new file mode 100644
index 0000000000000..071f5943b9720
--- /dev/null
+++ b/test/std/experimental/optional/optional.object/optional.object.ctor/const_T.pass.cpp
@@ -0,0 +1,117 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <optional>
+
+// constexpr optional(const T& v);
+
+#include <experimental/optional>
+#include <type_traits>
+#include <cassert>
+
+#if _LIBCPP_STD_VER > 11
+
+using std::experimental::optional;
+
+class X
+{
+    int i_;
+public:
+    X(int i) : i_(i) {}
+
+    friend bool operator==(const X& x, const X& y) {return x.i_ == y.i_;}
+};
+
+class Y
+{
+    int i_;
+public:
+    constexpr Y(int i) : i_(i) {}
+
+    friend constexpr bool operator==(const Y& x, const Y& y) {return x.i_ == y.i_;}
+};
+
+class Z
+{
+    int i_;
+public:
+    Z(int i) : i_(i) {}
+    Z(const Z&) {throw 6;}
+};
+
+
+#endif  // _LIBCPP_STD_VER > 11
+
+int main()
+{
+#if _LIBCPP_STD_VER > 11
+    {
+        typedef int T;
+        constexpr T t(5);
+        constexpr optional<T> opt(t);
+        static_assert(static_cast<bool>(opt) == true, "");
+        static_assert(*opt == 5, "");
+
+        struct test_constexpr_ctor
+            : public optional<T>
+        {
+            constexpr test_constexpr_ctor(const T&) {}
+        };
+
+    }
+    {
+        typedef double T;
+        constexpr T t(3);
+        constexpr optional<T> opt(t);
+        static_assert(static_cast<bool>(opt) == true, "");
+        static_assert(*opt == 3, "");
+
+        struct test_constexpr_ctor
+            : public optional<T>
+        {
+            constexpr test_constexpr_ctor(const T&) {}
+        };
+
+    }
+    {
+        typedef X T;
+        const T t(3);
+        optional<T> opt(t);
+        assert(static_cast<bool>(opt) == true);
+        assert(*opt == 3);
+    }
+    {
+        typedef Y T;
+        constexpr T t(3);
+        constexpr optional<T> opt(t);
+        static_assert(static_cast<bool>(opt) == true, "");
+        static_assert(*opt == 3, "");
+
+        struct test_constexpr_ctor
+            : public optional<T>
+        {
+            constexpr test_constexpr_ctor(const T&) {}
+        };
+
+    }
+    {
+        typedef Z T;
+        try
+        {
+            const T t(3);
+            optional<T> opt(t);
+            assert(false);
+        }
+        catch (int i)
+        {
+            assert(i == 6);
+        }
+    }
+#endif  // _LIBCPP_STD_VER > 11
+}
diff --git a/test/std/experimental/optional/optional.object/optional.object.ctor/copy.pass.cpp b/test/std/experimental/optional/optional.object/optional.object.ctor/copy.pass.cpp
new file mode 100644
index 0000000000000..8726f95a00c0e
--- /dev/null
+++ b/test/std/experimental/optional/optional.object/optional.object.ctor/copy.pass.cpp
@@ -0,0 +1,124 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <optional>
+
+// optional(const optional<T>& rhs);
+
+#include <experimental/optional>
+#include <type_traits>
+#include <cassert>
+
+#if _LIBCPP_STD_VER > 11
+
+using std::experimental::optional;
+
+template <class T>
+void
+test(const optional<T>& rhs, bool is_going_to_throw = false)
+{
+    bool rhs_engaged = static_cast<bool>(rhs);
+    try
+    {
+        optional<T> lhs = rhs;
+        assert(is_going_to_throw == false);
+        assert(static_cast<bool>(lhs) == rhs_engaged);
+        if (rhs_engaged)
+            assert(*lhs == *rhs);
+    }
+    catch (int i)
+    {
+        assert(i == 6);
+    }
+}
+
+class X
+{
+    int i_;
+public:
+    X(int i) : i_(i) {}
+    X(const X& x) : i_(x.i_) {}
+    ~X() {i_ = 0;}
+    friend bool operator==(const X& x, const X& y) {return x.i_ == y.i_;}
+};
+
+class Y
+{
+    int i_;
+public:
+    Y(int i) : i_(i) {}
+    Y(const Y& x) : i_(x.i_) {}
+
+    friend constexpr bool operator==(const Y& x, const Y& y) {return x.i_ == y.i_;}
+};
+
+int count = 0;
+
+class Z
+{
+    int i_;
+public:
+    Z(int i) : i_(i) {}
+    Z(const Z&)
+    {
+        if (++count == 2)
+            throw 6;
+    }
+
+    friend constexpr bool operator==(const Z& x, const Z& y) {return x.i_ == y.i_;}
+};
+
+
+#endif  // _LIBCPP_STD_VER > 11
+
+int main()
+{
+#if _LIBCPP_STD_VER > 11
+    {
+        typedef int T;
+        optional<T> rhs;
+        test(rhs);
+    }
+    {
+        typedef int T;
+        optional<T> rhs(3);
+        test(rhs);
+    }
+    {
+        typedef X T;
+        optional<T> rhs;
+        test(rhs);
+    }
+    {
+        typedef X T;
+        optional<T> rhs(X(3));
+        test(rhs);
+    }
+    {
+        typedef Y T;
+        optional<T> rhs;
+        test(rhs);
+    }
+    {
+        typedef Y T;
+        optional<T> rhs(Y(3));
+        test(rhs);
+    }
+    {
+        typedef Z T;
+        optional<T> rhs;
+        test(rhs);
+    }
+    {
+        typedef Z T;
+        optional<T> rhs(Z(3));
+        test(rhs, true);
+    }
+#endif  // _LIBCPP_STD_VER > 11
+}
diff --git a/test/std/experimental/optional/optional.object/optional.object.ctor/default.pass.cpp b/test/std/experimental/optional/optional.object/optional.object.ctor/default.pass.cpp
new file mode 100644
index 0000000000000..6a1763de22bd6
--- /dev/null
+++ b/test/std/experimental/optional/optional.object/optional.object.ctor/default.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.
+//
+//===----------------------------------------------------------------------===//
+
+// <optional>
+
+// constexpr optional() noexcept;
+
+#include <experimental/optional>
+#include <type_traits>
+#include <cassert>
+
+#if _LIBCPP_STD_VER > 11
+
+using std::experimental::optional;
+
+template <class Opt>
+void
+test_constexpr()
+{
+    static_assert(std::is_nothrow_default_constructible<Opt>::value, "");
+    constexpr Opt opt;
+    static_assert(static_cast<bool>(opt) == false, "");
+
+    struct test_constexpr_ctor
+        : public Opt
+    {
+        constexpr test_constexpr_ctor() {}
+    };
+
+}
+
+template <class Opt>
+void
+test()
+{
+    static_assert(std::is_nothrow_default_constructible<Opt>::value, "");
+    Opt opt;
+    assert(static_cast<bool>(opt) == false);
+
+    struct test_constexpr_ctor
+        : public Opt
+    {
+        constexpr test_constexpr_ctor() {}
+    };
+}
+
+struct X
+{
+    X();
+};
+
+#endif  // _LIBCPP_STD_VER > 11
+
+int main()
+{
+#if _LIBCPP_STD_VER > 11
+    test_constexpr<optional<int>>();
+    test_constexpr<optional<int*>>();
+    test<optional<X>>();
+#endif  // _LIBCPP_STD_VER > 11
+}
diff --git a/test/std/experimental/optional/optional.object/optional.object.ctor/in_place_t.pass.cpp b/test/std/experimental/optional/optional.object/optional.object.ctor/in_place_t.pass.cpp
new file mode 100644
index 0000000000000..412c993ffbd78
--- /dev/null
+++ b/test/std/experimental/optional/optional.object/optional.object.ctor/in_place_t.pass.cpp
@@ -0,0 +1,145 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <optional>
+
+// template <class... Args>
+//   constexpr explicit optional(in_place_t, Args&&... args);
+
+#include <experimental/optional>
+#include <type_traits>
+#include <cassert>
+
+#if _LIBCPP_STD_VER > 11
+
+using std::experimental::optional;
+using std::experimental::in_place_t;
+using std::experimental::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
+{
+    int i_;
+public:
+    Z(int i) : i_(i) {throw 6;}
+};
+
+
+#endif  // _LIBCPP_STD_VER > 11
+
+int main()
+{
+#if _LIBCPP_STD_VER > 11
+    {
+        constexpr optional<int> opt(in_place, 5);
+        static_assert(static_cast<bool>(opt) == true, "");
+        static_assert(*opt == 5, "");
+
+        struct test_constexpr_ctor
+            : public optional<int>
+        {
+            constexpr test_constexpr_ctor(in_place_t, int i) 
+                : optional<int>(in_place, i) {}
+        };
+
+    }
+    {
+        const optional<X> opt(in_place);
+        assert(static_cast<bool>(opt) == true);
+        assert(*opt == X());
+    }
+    {
+        const optional<X> opt(in_place, 5);
+        assert(static_cast<bool>(opt) == true);
+        assert(*opt == X(5));
+    }
+    {
+        const optional<X> opt(in_place, 5, 4);
+        assert(static_cast<bool>(opt) == true);
+        assert(*opt == X(5, 4));
+    }
+    {
+        constexpr optional<Y> opt(in_place);
+        static_assert(static_cast<bool>(opt) == true, "");
+        static_assert(*opt == Y(), "");
+
+        struct test_constexpr_ctor
+            : public optional<Y>
+        {
+            constexpr test_constexpr_ctor(in_place_t) 
+                : optional<Y>(in_place) {}
+        };
+
+    }
+    {
+        constexpr optional<Y> opt(in_place, 5);
+        static_assert(static_cast<bool>(opt) == true, "");
+        static_assert(*opt == Y(5), "");
+
+        struct test_constexpr_ctor
+            : public optional<Y>
+        {
+            constexpr test_constexpr_ctor(in_place_t, int i) 
+                : optional<Y>(in_place, i) {}
+        };
+
+    }
+    {
+        constexpr optional<Y> opt(in_place, 5, 4);
+        static_assert(static_cast<bool>(opt) == true, "");
+        static_assert(*opt == Y(5, 4), "");
+
+        struct test_constexpr_ctor
+            : public optional<Y>
+        {
+            constexpr test_constexpr_ctor(in_place_t, int i, int j) 
+                : optional<Y>(in_place, i, j) {}
+        };
+
+    }
+    {
+        try
+        {
+            const optional<Z> opt(in_place, 1);
+            assert(false);
+        }
+        catch (int i)
+        {
+            assert(i == 6);
+        }
+    }
+#endif  // _LIBCPP_STD_VER > 11
+}
diff --git a/test/std/experimental/optional/optional.object/optional.object.ctor/initializer_list.pass.cpp b/test/std/experimental/optional/optional.object/optional.object.ctor/initializer_list.pass.cpp
new file mode 100644
index 0000000000000..98cb929dc51e3
--- /dev/null
+++ b/test/std/experimental/optional/optional.object/optional.object.ctor/initializer_list.pass.cpp
@@ -0,0 +1,126 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <optional>
+
+// template <class U, class... Args>
+//     constexpr
+//     explicit optional(in_place_t, initializer_list<U> il, Args&&... args);
+
+#include <experimental/optional>
+#include <type_traits>
+#include <vector>
+#include <cassert>
+
+#if _LIBCPP_STD_VER > 11
+
+using std::experimental::optional;
+using std::experimental::in_place_t;
+using std::experimental::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:
+    constexpr Z() : i_(0) {}
+    constexpr Z(int i) : i_(i) {}
+    constexpr Z(std::initializer_list<int> il) : i_(il.begin()[0]), j_(il.begin()[1])
+        {throw 6;}
+
+    friend constexpr bool operator==(const Z& x, const Z& y)
+        {return x.i_ == y.i_ && x.j_ == y.j_;}
+};
+
+
+#endif  // _LIBCPP_STD_VER > 11
+
+int main()
+{
+#if _LIBCPP_STD_VER > 11
+    {
+        static_assert(!std::is_constructible<X, std::initializer_list<int>&>::value, "");
+        static_assert(!std::is_constructible<optional<X>, std::initializer_list<int>&>::value, "");
+    }
+    {
+        optional<std::vector<int>> opt(in_place, {3, 1});
+        assert(static_cast<bool>(opt) == true);
+        assert((*opt == std::vector<int>{3, 1}));
+        assert(opt->size() == 2);
+    }
+    {
+        optional<std::vector<int>> opt(in_place, {3, 1}, std::allocator<int>());
+        assert(static_cast<bool>(opt) == true);
+        assert((*opt == std::vector<int>{3, 1}));
+        assert(opt->size() == 2);
+    }
+    {
+        static_assert(std::is_constructible<optional<Y>, std::initializer_list<int>&>::value, "");
+        constexpr optional<Y> opt(in_place, {3, 1});
+        static_assert(static_cast<bool>(opt) == true, "");
+        static_assert(*opt == Y{3, 1}, "");
+
+        struct test_constexpr_ctor
+            : public optional<Y>
+        {
+            constexpr test_constexpr_ctor(in_place_t, std::initializer_list<int> i) 
+                : optional<Y>(in_place, i) {}
+        };
+
+    }
+    {
+        static_assert(std::is_constructible<optional<Z>, std::initializer_list<int>&>::value, "");
+        try
+        {
+            optional<Z> opt(in_place, {3, 1});
+            assert(false);
+        }
+        catch (int i)
+        {
+            assert(i == 6);
+        }
+
+        struct test_constexpr_ctor
+            : public optional<Z>
+        {
+            constexpr test_constexpr_ctor(in_place_t, std::initializer_list<int> i) 
+                : optional<Z>(in_place, i) {}
+        };
+
+    }
+#endif  // _LIBCPP_STD_VER > 11
+}
diff --git a/test/std/experimental/optional/optional.object/optional.object.ctor/move.pass.cpp b/test/std/experimental/optional/optional.object/optional.object.ctor/move.pass.cpp
new file mode 100644
index 0000000000000..b320c95c5827d
--- /dev/null
+++ b/test/std/experimental/optional/optional.object/optional.object.ctor/move.pass.cpp
@@ -0,0 +1,124 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <optional>
+
+// optional(optional<T>&& rhs) noexcept(is_nothrow_move_constructible<T>::value);
+
+#include <experimental/optional>
+#include <type_traits>
+#include <cassert>
+
+#if _LIBCPP_STD_VER > 11
+
+using std::experimental::optional;
+
+template <class T>
+void
+test(optional<T>& rhs, bool is_going_to_throw = false)
+{
+    static_assert(std::is_nothrow_move_constructible<optional<T>>::value ==
+                  std::is_nothrow_move_constructible<T>::value, "");
+    bool rhs_engaged = static_cast<bool>(rhs);
+    try
+    {
+        optional<T> lhs = std::move(rhs);
+        assert(is_going_to_throw == false);
+        assert(static_cast<bool>(lhs) == rhs_engaged);
+    }
+    catch (int i)
+    {
+        assert(i == 6);
+    }
+}
+
+class X
+{
+    int i_;
+public:
+    X(int i) : i_(i) {}
+    X(X&& x) : i_(x.i_) {x.i_ = 0;}
+    ~X() {i_ = 0;}
+    friend bool operator==(const X& x, const X& y) {return x.i_ == y.i_;}
+};
+
+class Y
+{
+    int i_;
+public:
+    Y(int i) : i_(i) {}
+    Y(Y&& x) noexcept : i_(x.i_) {x.i_ = 0;}
+
+    friend constexpr bool operator==(const Y& x, const Y& y) {return x.i_ == y.i_;}
+};
+
+int count = 0;
+
+class Z
+{
+    int i_;
+public:
+    Z(int i) : i_(i) {}
+    Z(Z&&)
+    {
+        if (++count == 2)
+            throw 6;
+    }
+
+    friend constexpr bool operator==(const Z& x, const Z& y) {return x.i_ == y.i_;}
+};
+
+
+#endif  // _LIBCPP_STD_VER > 11
+
+int main()
+{
+#if _LIBCPP_STD_VER > 11
+    {
+        typedef int T;
+        optional<T> rhs;
+        test(rhs);
+    }
+    {
+        typedef int T;
+        optional<T> rhs(3);
+        test(rhs);
+    }
+    {
+        typedef X T;
+        optional<T> rhs;
+        test(rhs);
+    }
+    {
+        typedef X T;
+        optional<T> rhs(X(3));
+        test(rhs);
+    }
+    {
+        typedef Y T;
+        optional<T> rhs;
+        test(rhs);
+    }
+    {
+        typedef Y T;
+        optional<T> rhs(Y(3));
+        test(rhs);
+    }
+    {
+        typedef Z T;
+        optional<T> rhs;
+        test(rhs);
+    }
+    {
+        typedef Z T;
+        optional<T> rhs(Z(3));
+        test(rhs, true);
+    }
+#endif  // _LIBCPP_STD_VER > 11
+}
diff --git a/test/std/experimental/optional/optional.object/optional.object.ctor/nullopt_t.pass.cpp b/test/std/experimental/optional/optional.object/optional.object.ctor/nullopt_t.pass.cpp
new file mode 100644
index 0000000000000..c307a2e1e258b
--- /dev/null
+++ b/test/std/experimental/optional/optional.object/optional.object.ctor/nullopt_t.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.
+//
+//===----------------------------------------------------------------------===//
+
+// <optional>
+
+// constexpr optional(nullopt_t) noexcept;
+
+#include <experimental/optional>
+#include <type_traits>
+#include <cassert>
+
+#if _LIBCPP_STD_VER > 11
+
+using std::experimental::optional;
+using std::experimental::nullopt_t;
+using std::experimental::nullopt;
+
+template <class Opt>
+void
+test_constexpr()
+{
+    static_assert(noexcept(Opt(nullopt)), "");
+    constexpr Opt opt(nullopt);
+    static_assert(static_cast<bool>(opt) == false, "");
+
+    struct test_constexpr_ctor
+        : public Opt
+    {
+        constexpr test_constexpr_ctor() {}
+    };
+}
+
+template <class Opt>
+void
+test()
+{
+    static_assert(noexcept(Opt(nullopt)), "");
+    Opt opt(nullopt);
+    assert(static_cast<bool>(opt) == false);
+
+    struct test_constexpr_ctor
+        : public Opt
+    {
+        constexpr test_constexpr_ctor() {}
+    };
+}
+
+struct X
+{
+    X();
+};
+
+#endif  // _LIBCPP_STD_VER > 11
+
+int main()
+{
+#if _LIBCPP_STD_VER > 11
+    test_constexpr<optional<int>>();
+    test_constexpr<optional<int*>>();
+    test<optional<X>>();
+#endif  // _LIBCPP_STD_VER > 11
+}
diff --git a/test/std/experimental/optional/optional.object/optional.object.ctor/rvalue_T.pass.cpp b/test/std/experimental/optional/optional.object/optional.object.ctor/rvalue_T.pass.cpp
new file mode 100644
index 0000000000000..ac52a42d59538
--- /dev/null
+++ b/test/std/experimental/optional/optional.object/optional.object.ctor/rvalue_T.pass.cpp
@@ -0,0 +1,110 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <optional>
+
+// constexpr optional(T&& v);
+
+#include <experimental/optional>
+#include <type_traits>
+#include <cassert>
+
+#if _LIBCPP_STD_VER > 11
+
+using std::experimental::optional;
+
+class X
+{
+    int i_;
+public:
+    X(int i) : i_(i) {}
+    X(X&& x) : i_(x.i_) {}
+
+    friend bool operator==(const X& x, const X& y) {return x.i_ == y.i_;}
+};
+
+class Y
+{
+    int i_;
+public:
+    constexpr Y(int i) : i_(i) {}
+    constexpr Y(Y&& x) : i_(x.i_) {}
+
+    friend constexpr bool operator==(const Y& x, const Y& y) {return x.i_ == y.i_;}
+};
+
+class Z
+{
+    int i_;
+public:
+    Z(int i) : i_(i) {}
+    Z(Z&&) {throw 6;}
+};
+
+#endif  // _LIBCPP_STD_VER > 11
+
+int main()
+{
+#if _LIBCPP_STD_VER > 11
+    {
+        typedef int T;
+        constexpr optional<T> opt(T(5));
+        static_assert(static_cast<bool>(opt) == true, "");
+        static_assert(*opt == 5, "");
+
+        struct test_constexpr_ctor
+            : public optional<T>
+        {
+            constexpr test_constexpr_ctor(T&&) {}
+        };
+    }
+    {
+        typedef double T;
+        constexpr optional<T> opt(T(3));
+        static_assert(static_cast<bool>(opt) == true, "");
+        static_assert(*opt == 3, "");
+
+        struct test_constexpr_ctor
+            : public optional<T>
+        {
+            constexpr test_constexpr_ctor(T&&) {}
+        };
+    }
+    {
+        typedef X T;
+        optional<T> opt(T(3));
+        assert(static_cast<bool>(opt) == true);
+        assert(*opt == 3);
+    }
+    {
+        typedef Y T;
+        constexpr optional<T> opt(T(3));
+        static_assert(static_cast<bool>(opt) == true, "");
+        static_assert(*opt == 3, "");
+
+        struct test_constexpr_ctor
+            : public optional<T>
+        {
+            constexpr test_constexpr_ctor(T&&) {}
+        };
+    }
+    {
+        typedef Z T;
+        try
+        {
+            optional<T> opt(T(3));
+            assert(false);
+        }
+        catch (int i)
+        {
+            assert(i == 6);
+        }
+    }
+#endif  // _LIBCPP_STD_VER > 11
+}