1 files changed, 121 insertions, 0 deletions
diff --git a/test/std/utilities/optional/optional.object/optional.object.ctor/explicit_const_optional_U.pass.cpp b/test/std/utilities/optional/optional.object/optional.object.ctor/explicit_const_optional_U.pass.cpp
new file mode 100644
index 000000000000..64ac05316c2a
--- /dev/null
+++ b/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);
+    }
+}