Index: include/array
===================================================================
--- include/array
+++ include/array
@@ -247,11 +247,13 @@
     typedef std::reverse_iterator<iterator>       reverse_iterator;
     typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
 
-    typedef typename conditional<is_const<_Tp>::value, const char,
-                                char>::type _CharType;
+    union __wrapper {
+        constexpr __wrapper(): __b() {}
+        ~__wrapper() = default;
 
-    struct  _ArrayInStructT { _Tp __data_[1]; };
-    _ALIGNAS_TYPE(_ArrayInStructT) _CharType __elems_[sizeof(_ArrayInStructT)];
+        bool __b;
+        _Tp __t;
+    } __w;
 
     // No explicit construct/copy/destroy for aggregate type
     _LIBCPP_INLINE_VISIBILITY void fill(const value_type&) {
@@ -266,31 +268,31 @@
     }
 
     // iterators:
-    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
     iterator begin() _NOEXCEPT {return iterator(data());}
-    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
     const_iterator begin() const _NOEXCEPT {return const_iterator(data());}
-    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
     iterator end() _NOEXCEPT {return iterator(data());}
-    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
     const_iterator end() const _NOEXCEPT {return const_iterator(data());}
 
-    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
     reverse_iterator rbegin() _NOEXCEPT {return reverse_iterator(end());}
-    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
     const_reverse_iterator rbegin() const _NOEXCEPT {return const_reverse_iterator(end());}
-    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
     reverse_iterator rend() _NOEXCEPT {return reverse_iterator(begin());}
-    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
     const_reverse_iterator rend() const _NOEXCEPT {return const_reverse_iterator(begin());}
 
-    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
     const_iterator cbegin() const _NOEXCEPT {return begin();}
-    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
     const_iterator cend() const _NOEXCEPT {return end();}
-    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
     const_reverse_iterator crbegin() const _NOEXCEPT {return rbegin();}
-    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
     const_reverse_iterator crend() const _NOEXCEPT {return rend();}
 
     // capacity:
@@ -302,7 +304,7 @@
     _LIBCPP_CONSTEXPR bool empty() const _NOEXCEPT {return true;}
 
     // element access:
-    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
     reference operator[](size_type) _NOEXCEPT {
       _LIBCPP_ASSERT(false, "cannot call array<T, 0>::operator[] on a zero-sized array");
       _LIBCPP_UNREACHABLE();
@@ -314,46 +316,46 @@
       _LIBCPP_UNREACHABLE();
     }
 
-    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
     reference at(size_type) {
       __throw_out_of_range("array<T, 0>::at");
       _LIBCPP_UNREACHABLE();
     }
 
-    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
     const_reference at(size_type) const {
       __throw_out_of_range("array<T, 0>::at");
       _LIBCPP_UNREACHABLE();
     }
 
-    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
     reference front() _NOEXCEPT {
       _LIBCPP_ASSERT(false, "cannot call array<T, 0>::front() on a zero-sized array");
       _LIBCPP_UNREACHABLE();
     }
 
-    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
     const_reference front() const _NOEXCEPT {
       _LIBCPP_ASSERT(false, "cannot call array<T, 0>::front() on a zero-sized array");
       _LIBCPP_UNREACHABLE();
     }
 
-    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
     reference back() _NOEXCEPT {
       _LIBCPP_ASSERT(false, "cannot call array<T, 0>::back() on a zero-sized array");
       _LIBCPP_UNREACHABLE();
     }
 
-    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
     const_reference back() const _NOEXCEPT {
       _LIBCPP_ASSERT(false, "cannot call array<T, 0>::back() on a zero-sized array");
       _LIBCPP_UNREACHABLE();
     }
 
-    _LIBCPP_INLINE_VISIBILITY
-    value_type* data() _NOEXCEPT {return reinterpret_cast<value_type*>(__elems_);}
-    _LIBCPP_INLINE_VISIBILITY
-    const value_type* data() const _NOEXCEPT {return reinterpret_cast<const value_type*>(__elems_);}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    value_type* data() _NOEXCEPT {return &__w.__t;}
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+    const value_type* data() const _NOEXCEPT {return &__w.__t;}
 };
 
 
Index: test/std/containers/sequences/array/size_and_alignment.pass.cpp
===================================================================
--- test/std/containers/sequences/array/size_and_alignment.pass.cpp
+++ test/std/containers/sequences/array/size_and_alignment.pass.cpp
@@ -20,6 +20,12 @@
 
 #include "test_macros.h"
 
+template <class A>
+inline constexpr bool has_consexpr_members(const A& arr) {
+    return arr.begin() &&
+           arr.end()   &&
+           arr.data();
+}
 
 template <class T, size_t Size>
 struct MyArray {
@@ -34,12 +40,15 @@
   static_assert(sizeof(ArrayT) == sizeof(CArrayT), "");
   static_assert(sizeof(ArrayT) == sizeof(MyArrayT), "");
   static_assert(TEST_ALIGNOF(ArrayT) == TEST_ALIGNOF(MyArrayT), "");
-#if defined(_LIBCPP_VERSION)
+#if defined(_LIBCPP_VERSION) && Size > 0
   ArrayT a;
   ((void)a);
   static_assert(sizeof(ArrayT) == sizeof(a.__elems_), "");
   static_assert(TEST_ALIGNOF(ArrayT) == __alignof__(a.__elems_), "");
 #endif
+#if TEST_STD_VER > 17
+  static_assert(has_consexpr_members(ArrayT { }));
+#endif
 }
 
 template <class T>