Index: include/memory
===================================================================
--- include/memory
+++ include/memory
@@ -2096,24 +2096,28 @@
     typedef const typename remove_reference<_T1>::type& _T1_const_reference;
     typedef const typename remove_reference<_T2>::type& _T2_const_reference;
 
-    _LIBCPP_INLINE_VISIBILITY __libcpp_compressed_pair_imp() : __first_(), __second_() {}
-    _LIBCPP_INLINE_VISIBILITY explicit __libcpp_compressed_pair_imp(_T1_param __t1)
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
+    __libcpp_compressed_pair_imp() : __first_(), __second_() {}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
+    explicit __libcpp_compressed_pair_imp(_T1_param __t1)
         : __first_(_VSTD::forward<_T1_param>(__t1)), __second_() {}
-    _LIBCPP_INLINE_VISIBILITY explicit __libcpp_compressed_pair_imp(_T2_param __t2)
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
+    explicit __libcpp_compressed_pair_imp(_T2_param __t2)
         : __first_(), __second_(_VSTD::forward<_T2_param>(__t2)) {}
-    _LIBCPP_INLINE_VISIBILITY __libcpp_compressed_pair_imp(_T1_param __t1, _T2_param __t2)
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
+    __libcpp_compressed_pair_imp(_T1_param __t1, _T2_param __t2)
         : __first_(_VSTD::forward<_T1_param>(__t1)), __second_(_VSTD::forward<_T2_param>(__t2)) {}
 
 #if defined(_LIBCPP_HAS_NO_DEFAULTED_FUNCTIONS) && !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
 
-    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
     __libcpp_compressed_pair_imp(const __libcpp_compressed_pair_imp& __p)
         _NOEXCEPT_(is_nothrow_copy_constructible<_T1>::value &&
                    is_nothrow_copy_constructible<_T2>::value)
         : __first_(__p.first()),
           __second_(__p.second()) {}
 
-    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
     __libcpp_compressed_pair_imp& operator=(const __libcpp_compressed_pair_imp& __p)
         _NOEXCEPT_(is_nothrow_copy_assignable<_T1>::value &&
                    is_nothrow_copy_assignable<_T2>::value)
@@ -2123,14 +2127,14 @@
             return *this;
         }
 
-    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
     __libcpp_compressed_pair_imp(__libcpp_compressed_pair_imp&& __p)
         _NOEXCEPT_(is_nothrow_move_constructible<_T1>::value &&
                    is_nothrow_move_constructible<_T2>::value)
         : __first_(_VSTD::forward<_T1>(__p.first())),
           __second_(_VSTD::forward<_T2>(__p.second())) {}
 
-    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
     __libcpp_compressed_pair_imp& operator=(__libcpp_compressed_pair_imp&& __p)
         _NOEXCEPT_(is_nothrow_move_assignable<_T1>::value &&
                    is_nothrow_move_assignable<_T2>::value)
@@ -2145,7 +2149,7 @@
 #ifndef _LIBCPP_HAS_NO_VARIADICS
 
     template <class... _Args1, class... _Args2, size_t... _I1, size_t... _I2>
-        _LIBCPP_INLINE_VISIBILITY
+        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
         __libcpp_compressed_pair_imp(piecewise_construct_t __pc,
                                      tuple<_Args1...> __first_args,
                                      tuple<_Args2...> __second_args,
@@ -2189,23 +2193,27 @@
     typedef const _T1&                                        _T1_const_reference;
     typedef const typename remove_reference<_T2>::type& _T2_const_reference;
 
-    _LIBCPP_INLINE_VISIBILITY __libcpp_compressed_pair_imp() : __second_() {}
-    _LIBCPP_INLINE_VISIBILITY explicit __libcpp_compressed_pair_imp(_T1_param __t1)
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
+    __libcpp_compressed_pair_imp() : __second_() {}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
+    explicit __libcpp_compressed_pair_imp(_T1_param __t1)
         : _T1(_VSTD::forward<_T1_param>(__t1)), __second_() {}
-    _LIBCPP_INLINE_VISIBILITY explicit __libcpp_compressed_pair_imp(_T2_param __t2)
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
+    explicit __libcpp_compressed_pair_imp(_T2_param __t2)
         : __second_(_VSTD::forward<_T2_param>(__t2)) {}
-    _LIBCPP_INLINE_VISIBILITY __libcpp_compressed_pair_imp(_T1_param __t1, _T2_param __t2)
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
+    __libcpp_compressed_pair_imp(_T1_param __t1, _T2_param __t2)
         : _T1(_VSTD::forward<_T1_param>(__t1)), __second_(_VSTD::forward<_T2_param>(__t2)) {}
 
 #if defined(_LIBCPP_HAS_NO_DEFAULTED_FUNCTIONS) && !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
 
-    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
     __libcpp_compressed_pair_imp(const __libcpp_compressed_pair_imp& __p)
         _NOEXCEPT_(is_nothrow_copy_constructible<_T1>::value &&
                    is_nothrow_copy_constructible<_T2>::value)
         : _T1(__p.first()), __second_(__p.second()) {}
 
-    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
     __libcpp_compressed_pair_imp& operator=(const __libcpp_compressed_pair_imp& __p)
         _NOEXCEPT_(is_nothrow_copy_assignable<_T1>::value &&
                    is_nothrow_copy_assignable<_T2>::value)
@@ -2215,13 +2223,13 @@
             return *this;
         }
 
-    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
     __libcpp_compressed_pair_imp(__libcpp_compressed_pair_imp&& __p)
         _NOEXCEPT_(is_nothrow_move_constructible<_T1>::value &&
                    is_nothrow_move_constructible<_T2>::value)
         : _T1(_VSTD::move(__p.first())), __second_(_VSTD::forward<_T2>(__p.second())) {}
 
-    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
     __libcpp_compressed_pair_imp& operator=(__libcpp_compressed_pair_imp&& __p)
         _NOEXCEPT_(is_nothrow_move_assignable<_T1>::value &&
                    is_nothrow_move_assignable<_T2>::value)
@@ -2236,7 +2244,7 @@
 #ifndef _LIBCPP_HAS_NO_VARIADICS
 
     template <class... _Args1, class... _Args2, size_t... _I1, size_t... _I2>
-        _LIBCPP_INLINE_VISIBILITY
+        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
         __libcpp_compressed_pair_imp(piecewise_construct_t __pc,
                                      tuple<_Args1...> __first_args,
                                      tuple<_Args2...> __second_args,
@@ -2279,25 +2287,29 @@
     typedef const typename remove_reference<_T1>::type& _T1_const_reference;
     typedef const _T2&                                        _T2_const_reference;
 
-    _LIBCPP_INLINE_VISIBILITY __libcpp_compressed_pair_imp() : __first_() {}
-    _LIBCPP_INLINE_VISIBILITY explicit __libcpp_compressed_pair_imp(_T1_param __t1)
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
+    __libcpp_compressed_pair_imp() : __first_() {}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
+    explicit __libcpp_compressed_pair_imp(_T1_param __t1)
         : __first_(_VSTD::forward<_T1_param>(__t1)) {}
-    _LIBCPP_INLINE_VISIBILITY explicit __libcpp_compressed_pair_imp(_T2_param __t2)
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
+    explicit __libcpp_compressed_pair_imp(_T2_param __t2)
         : _T2(_VSTD::forward<_T2_param>(__t2)), __first_() {}
-    _LIBCPP_INLINE_VISIBILITY __libcpp_compressed_pair_imp(_T1_param __t1, _T2_param __t2)
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
+    __libcpp_compressed_pair_imp(_T1_param __t1, _T2_param __t2)
         _NOEXCEPT_(is_nothrow_move_constructible<_T1>::value &&
                    is_nothrow_move_constructible<_T2>::value)
         : _T2(_VSTD::forward<_T2_param>(__t2)), __first_(_VSTD::forward<_T1_param>(__t1)) {}
 
 #if defined(_LIBCPP_HAS_NO_DEFAULTED_FUNCTIONS) && !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
 
-    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
     __libcpp_compressed_pair_imp(const __libcpp_compressed_pair_imp& __p)
         _NOEXCEPT_(is_nothrow_copy_constructible<_T1>::value &&
                    is_nothrow_copy_constructible<_T2>::value)
         : _T2(__p.second()), __first_(__p.first()) {}
 
-    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
     __libcpp_compressed_pair_imp& operator=(const __libcpp_compressed_pair_imp& __p)
         _NOEXCEPT_(is_nothrow_copy_assignable<_T1>::value &&
                    is_nothrow_copy_assignable<_T2>::value)
@@ -2307,13 +2319,13 @@
             return *this;
         }
 
-    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
     __libcpp_compressed_pair_imp(__libcpp_compressed_pair_imp&& __p)
         _NOEXCEPT_(is_nothrow_move_constructible<_T1>::value &&
                    is_nothrow_move_constructible<_T2>::value)
         : _T2(_VSTD::forward<_T2>(__p.second())), __first_(_VSTD::move(__p.first())) {}
 
-    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
     __libcpp_compressed_pair_imp& operator=(__libcpp_compressed_pair_imp&& __p)
         _NOEXCEPT_(is_nothrow_move_assignable<_T1>::value &&
                    is_nothrow_move_assignable<_T2>::value)
@@ -2328,7 +2340,7 @@
 #ifndef _LIBCPP_HAS_NO_VARIADICS
 
     template <class... _Args1, class... _Args2, size_t... _I1, size_t... _I2>
-        _LIBCPP_INLINE_VISIBILITY
+        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
         __libcpp_compressed_pair_imp(piecewise_construct_t __pc,
                                      tuple<_Args1...> __first_args,
                                      tuple<_Args2...> __second_args,
@@ -2371,23 +2383,27 @@
     typedef const _T1& _T1_const_reference;
     typedef const _T2& _T2_const_reference;
 
-    _LIBCPP_INLINE_VISIBILITY __libcpp_compressed_pair_imp() {}
-    _LIBCPP_INLINE_VISIBILITY explicit __libcpp_compressed_pair_imp(_T1_param __t1)
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
+    __libcpp_compressed_pair_imp() {}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
+    explicit __libcpp_compressed_pair_imp(_T1_param __t1)
         : _T1(_VSTD::forward<_T1_param>(__t1)) {}
-    _LIBCPP_INLINE_VISIBILITY explicit __libcpp_compressed_pair_imp(_T2_param __t2)
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
+    explicit __libcpp_compressed_pair_imp(_T2_param __t2)
         : _T2(_VSTD::forward<_T2_param>(__t2)) {}
-    _LIBCPP_INLINE_VISIBILITY __libcpp_compressed_pair_imp(_T1_param __t1, _T2_param __t2)
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
+    __libcpp_compressed_pair_imp(_T1_param __t1, _T2_param __t2)
         : _T1(_VSTD::forward<_T1_param>(__t1)), _T2(_VSTD::forward<_T2_param>(__t2)) {}
 
 #if defined(_LIBCPP_HAS_NO_DEFAULTED_FUNCTIONS) && !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
 
-    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
     __libcpp_compressed_pair_imp(const __libcpp_compressed_pair_imp& __p)
         _NOEXCEPT_(is_nothrow_copy_constructible<_T1>::value &&
                    is_nothrow_copy_constructible<_T2>::value)
         : _T1(__p.first()), _T2(__p.second()) {}
 
-    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
     __libcpp_compressed_pair_imp& operator=(const __libcpp_compressed_pair_imp& __p)
         _NOEXCEPT_(is_nothrow_copy_assignable<_T1>::value &&
                    is_nothrow_copy_assignable<_T2>::value)
@@ -2397,13 +2413,13 @@
             return *this;
         }
 
-    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
     __libcpp_compressed_pair_imp(__libcpp_compressed_pair_imp&& __p)
         _NOEXCEPT_(is_nothrow_move_constructible<_T1>::value &&
                    is_nothrow_move_constructible<_T2>::value)
         : _T1(_VSTD::move(__p.first())), _T2(_VSTD::move(__p.second())) {}
 
-    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
     __libcpp_compressed_pair_imp& operator=(__libcpp_compressed_pair_imp&& __p)
         _NOEXCEPT_(is_nothrow_move_assignable<_T1>::value &&
                    is_nothrow_move_assignable<_T2>::value)
@@ -2418,7 +2434,7 @@
 #ifndef _LIBCPP_HAS_NO_VARIADICS
 
     template <class... _Args1, class... _Args2, size_t... _I1, size_t... _I2>
-        _LIBCPP_INLINE_VISIBILITY
+        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
         __libcpp_compressed_pair_imp(piecewise_construct_t __pc,
                                      tuple<_Args1...> __first_args,
                                      tuple<_Args2...> __second_args,
@@ -2458,44 +2474,45 @@
     typedef typename base::_T1_const_reference _T1_const_reference;
     typedef typename base::_T2_const_reference _T2_const_reference;
 
-    _LIBCPP_INLINE_VISIBILITY __compressed_pair() {}
-    _LIBCPP_INLINE_VISIBILITY explicit __compressed_pair(_T1_param __t1)
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR __compressed_pair() {}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
+    explicit __compressed_pair(_T1_param __t1)
         : base(_VSTD::forward<_T1_param>(__t1)) {}
-    _LIBCPP_INLINE_VISIBILITY explicit __compressed_pair(_T2_param __t2)
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
+    explicit __compressed_pair(_T2_param __t2)
         : base(_VSTD::forward<_T2_param>(__t2)) {}
-    _LIBCPP_INLINE_VISIBILITY __compressed_pair(_T1_param __t1, _T2_param __t2)
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
+    __compressed_pair(_T1_param __t1, _T2_param __t2)
         : base(_VSTD::forward<_T1_param>(__t1), _VSTD::forward<_T2_param>(__t2)) {}
 
 #if defined(_LIBCPP_HAS_NO_DEFAULTED_FUNCTIONS) && !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
 
-    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
     __compressed_pair(const __compressed_pair& __p)
         _NOEXCEPT_(is_nothrow_copy_constructible<_T1>::value &&
                    is_nothrow_copy_constructible<_T2>::value)
         : base(__p) {}
 
-    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
     __compressed_pair& operator=(const __compressed_pair& __p)
         _NOEXCEPT_(is_nothrow_copy_assignable<_T1>::value &&
                    is_nothrow_copy_assignable<_T2>::value)
         {
-            base::operator=(__p);
-            return *this;
+            return base::operator=(__p), *this;
         }
 
-    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
     __compressed_pair(__compressed_pair&& __p)
         _NOEXCEPT_(is_nothrow_move_constructible<_T1>::value &&
                    is_nothrow_move_constructible<_T2>::value)
         : base(_VSTD::move(__p)) {}
 
-    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
     __compressed_pair& operator=(__compressed_pair&& __p)
         _NOEXCEPT_(is_nothrow_move_assignable<_T1>::value &&
                    is_nothrow_move_assignable<_T2>::value)
         {
-            base::operator=(_VSTD::move(__p));
-            return *this;
+            return base::operator=(_VSTD::move(__p)), *this;
         }
 
 #endif  // defined(_LIBCPP_HAS_NO_DEFAULTED_FUNCTIONS) && !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
@@ -2503,7 +2520,7 @@
 #ifndef _LIBCPP_HAS_NO_VARIADICS
 
     template <class... _Args1, class... _Args2>
-        _LIBCPP_INLINE_VISIBILITY
+        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
         __compressed_pair(piecewise_construct_t __pc, tuple<_Args1...> __first_args,
                                                       tuple<_Args2...> __second_args)
             : base(__pc, _VSTD::move(__first_args), _VSTD::move(__second_args),
Index: test/std/utilities/memory/unique.ptr/unique.ptr.runtime/constinit.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/memory/unique.ptr/unique.ptr.runtime/constinit.pass.cpp
@@ -0,0 +1,70 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03
+
+#include <cassert>
+#include <memory>
+
+#ifndef _LIBCPP_SAFE_STATIC
+#define _LIBCPP_SAFE_STATIC
+#endif
+
+// This is basically std::default delete, except that it is not empty such that
+// we test a different code path in the implementation
+template <class Tp> struct nonempty_delete {
+  uint32_t sentinel;
+  inline constexpr nonempty_delete() noexcept : sentinel(0xDEADBEEF) {}
+  template <class Up>
+  constexpr inline nonempty_delete(
+      const nonempty_delete<Up> &,
+      typename std::enable_if<std::is_convertible<Up *, Tp *>::value>::type * =
+          0) noexcept : sentinel(0xBAADF00D) {}
+  inline void operator()(Tp *ptr) const noexcept {
+    assert(sentinel == 0xDEADBEEF || sentinel == 0xBAADF00D);
+    delete[] ptr;
+  }
+};
+
+extern std::unique_ptr<int[]> a;
+extern std::unique_ptr<int[]> b;
+extern std::unique_ptr<int[], nonempty_delete<int>> c;
+extern std::unique_ptr<int[], nonempty_delete<int>> d;
+void *tramplea = std::memset(&a, 0xab, sizeof(a));
+void *trampleb = std::memset(&b, 0xab, sizeof(b));
+void *tramplec = std::memset(&a, 0xab, sizeof(c));
+void *trampled = std::memset(&b, 0xab, sizeof(d));
+_LIBCPP_SAFE_STATIC std::unique_ptr<int[]> a;
+_LIBCPP_SAFE_STATIC std::unique_ptr<int[]> b(nullptr);
+_LIBCPP_SAFE_STATIC std::unique_ptr<int[], nonempty_delete<int>> c;
+_LIBCPP_SAFE_STATIC std::unique_ptr<int[], nonempty_delete<int>> d(nullptr);
+
+int main() {
+  // Check that the initialization of 'a' was performed before the
+  // initialization of 'tramplea'.
+  for (size_t n = 0; n != sizeof(a); ++n)
+    assert(reinterpret_cast<unsigned char *>(tramplea)[n] == 0xab);
+  // Check that the initialization of 'b' was performed before the
+  // initialization of 'trampleb'.
+  for (size_t n = 0; n != sizeof(b); ++n)
+    assert(reinterpret_cast<unsigned char *>(trampleb)[n] == 0xab);
+  // Check that the initialization of 'c' was performed before the
+  // initialization of 'tramplec'.
+  for (size_t n = 0; n != sizeof(c); ++n)
+    assert(reinterpret_cast<unsigned char *>(tramplec)[n] == 0xab);
+  // Check that the initialization of 'd' was performed before the
+  // initialization of 'trampled'.
+  for (size_t n = 0; n != sizeof(d); ++n)
+    assert(reinterpret_cast<unsigned char *>(trampled)[n] == 0xab);
+  // Put a unique_ptr object back so that the global dtor is valid.
+  new (&a) std::unique_ptr<int[]>;
+  new (&b) std::unique_ptr<int[]>;
+  new (&c) std::unique_ptr<int[], nonempty_delete<int>>;
+  new (&d) std::unique_ptr<int[], nonempty_delete<int>>;
+}
Index: test/std/utilities/memory/unique.ptr/unique.ptr.single/constinit.pass.cpp
===================================================================
--- /dev/null
+++ test/std/utilities/memory/unique.ptr/unique.ptr.single/constinit.pass.cpp
@@ -0,0 +1,70 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03
+
+#include <cassert>
+#include <memory>
+
+#ifndef _LIBCPP_SAFE_STATIC
+#define _LIBCPP_SAFE_STATIC
+#endif
+
+// This is basically std::default delete, except that it is not empty such that
+// we test a different code path in the implementation
+template <class Tp> struct nonempty_delete {
+  uint32_t sentinel;
+  inline constexpr nonempty_delete() noexcept : sentinel(0xDEADBEEF) {}
+  template <class Up>
+  constexpr inline nonempty_delete(
+      const nonempty_delete<Up> &,
+      typename std::enable_if<std::is_convertible<Up *, Tp *>::value>::type * =
+          0) noexcept : sentinel(0xBAADF00D) {}
+  inline void operator()(Tp *ptr) const noexcept {
+    assert(sentinel == 0xDEADBEEF || sentinel == 0xBAADF00D);
+    delete ptr;
+  }
+};
+
+extern std::unique_ptr<int> a;
+extern std::unique_ptr<int> b;
+extern std::unique_ptr<int, nonempty_delete<int>> c;
+extern std::unique_ptr<int, nonempty_delete<int>> d;
+void *tramplea = std::memset(&a, 0xab, sizeof(a));
+void *trampleb = std::memset(&b, 0xab, sizeof(b));
+void *tramplec = std::memset(&a, 0xab, sizeof(c));
+void *trampled = std::memset(&b, 0xab, sizeof(d));
+_LIBCPP_SAFE_STATIC std::unique_ptr<int> a;
+_LIBCPP_SAFE_STATIC std::unique_ptr<int> b(nullptr);
+_LIBCPP_SAFE_STATIC std::unique_ptr<int, nonempty_delete<int>> c;
+_LIBCPP_SAFE_STATIC std::unique_ptr<int, nonempty_delete<int>> d(nullptr);
+
+int main() {
+  // Check that the initialization of 'a' was performed before the
+  // initialization of 'tramplea'.
+  for (size_t n = 0; n != sizeof(a); ++n)
+    assert(reinterpret_cast<unsigned char *>(tramplea)[n] == 0xab);
+  // Check that the initialization of 'b' was performed before the
+  // initialization of 'trampleb'.
+  for (size_t n = 0; n != sizeof(b); ++n)
+    assert(reinterpret_cast<unsigned char *>(trampleb)[n] == 0xab);
+  // Check that the initialization of 'c' was performed before the
+  // initialization of 'tramplec'.
+  for (size_t n = 0; n != sizeof(c); ++n)
+    assert(reinterpret_cast<unsigned char *>(tramplec)[n] == 0xab);
+  // Check that the initialization of 'd' was performed before the
+  // initialization of 'trampled'.
+  for (size_t n = 0; n != sizeof(d); ++n)
+    assert(reinterpret_cast<unsigned char *>(trampled)[n] == 0xab);
+  // Put a unique_ptr object back so that the global dtor is valid.
+  new (&a) std::unique_ptr<int>;
+  new (&b) std::unique_ptr<int>;
+  new (&c) std::unique_ptr<int, nonempty_delete<int>>;
+  new (&d) std::unique_ptr<int, nonempty_delete<int>>;
+}