Add array support to std::shared_ptr for C++17

	* doc/xml/manual/status_cxx2017.xml: Update status.
	* doc/html/manual/status.html: Regenerate.
	* include/bits/shared_ptr.h (shared_ptr(unique_ptr<_Yp, _Del>)): Add
	extension constructor to maintain C++14 behaviour.
	* include/bits/shared_ptr_base.h (__sp_array_delete): Add new struct.
	(__shared_count(_Ptr, false_type), __shared_count(_Ptr, true_type)):
	New constructors.
	(__sp_compatible_with, __sp_is_constructible): Add specializations
	for array support.
	(__sp_is_constructible_arr, __sp_is_constructible_arrN): New helpers.
	(__shared_ptr_access): New base class for observer member functions.
	(__shared_ptr::element_type): Use remove_extent.
	(__shared_ptr::_UniqCompatible): Add __sp_compatible_with check.
	(__shared_ptr(_Yp*)): Use tag dispatching to call new __shared_count
	constructor.
	(__shared_ptr(unique_ptr<_Yp, _Del>)): Add extension constructor.
	(__shared_ptr::operator*, __shared_ptr::operator->): Remove and
	inherit from __shared_ptr_access base class.
	(__shared_ptr::__has_esft_base): Return false for array types.
	(__weak_ptr::element_type): Use remove_extent.
	* include/experimental/bits/shared_ptr.h (__libfund_v1): Remove.
	(__shared_ptr<__libfund_v1<_Tp>>): Remove specializations.
	(__wak_ptr<__libfund_v1<_Tp>>): Likewise.
	(experimental::__sp_compatible_v): Redefine using
	__sp_compatible_with.
	(experimental::__sp_is_constructible_v): Redefine using
	__sp_is_constructible.
	(get_deleter, operator<<): Change argument from __shared_ptr to
	shared_ptr.
	* testsuite/20_util/shared_ptr/cons/array.cc: New test.
	* testsuite/20_util/shared_ptr/cons/unique_ptr_array.cc: Adjust for
	new behaviour.
	* testsuite/20_util/shared_ptr/observers/array.cc: Test observers for
	arrays.
	* testsuite/20_util/shared_ptr/observers/array_neg.cc: New test.

From-SVN: r242369

9 files changed, 617 insertions, 686 deletions

diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index 3df60de..83a6139 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,41 @@
+2016-11-13  Jonathan Wakely  <jwakely@redhat.com>
+
+	* doc/xml/manual/status_cxx2017.xml: Update status.
+	* doc/html/manual/status.html: Regenerate.
+	* include/bits/shared_ptr.h (shared_ptr(unique_ptr<_Yp, _Del>)): Add
+	extension constructor to maintain C++14 behaviour.
+	* include/bits/shared_ptr_base.h (__sp_array_delete): Add new struct.
+	(__shared_count(_Ptr, false_type), __shared_count(_Ptr, true_type)):
+	New constructors.
+	(__sp_compatible_with, __sp_is_constructible): Add specializations
+	for array support.
+	(__sp_is_constructible_arr, __sp_is_constructible_arrN): New helpers.
+	(__shared_ptr_access): New base class for observer member functions.
+	(__shared_ptr::element_type): Use remove_extent.
+	(__shared_ptr::_UniqCompatible): Add __sp_compatible_with check.
+	(__shared_ptr(_Yp*)): Use tag dispatching to call new __shared_count
+	constructor.
+	(__shared_ptr(unique_ptr<_Yp, _Del>)): Add extension constructor.
+	(__shared_ptr::operator*, __shared_ptr::operator->): Remove and
+	inherit from __shared_ptr_access base class.
+	(__shared_ptr::__has_esft_base): Return false for array types.
+	(__weak_ptr::element_type): Use remove_extent.
+	* include/experimental/bits/shared_ptr.h (__libfund_v1): Remove.
+	(__shared_ptr<__libfund_v1<_Tp>>): Remove specializations.
+	(__wak_ptr<__libfund_v1<_Tp>>): Likewise.
+	(experimental::__sp_compatible_v): Redefine using
+	__sp_compatible_with.
+	(experimental::__sp_is_constructible_v): Redefine using
+	__sp_is_constructible.
+	(get_deleter, operator<<): Change argument from __shared_ptr to
+	shared_ptr.
+	* testsuite/20_util/shared_ptr/cons/array.cc: New test.
+	* testsuite/20_util/shared_ptr/cons/unique_ptr_array.cc: Adjust for
+	new behaviour.
+	* testsuite/20_util/shared_ptr/observers/array.cc: Test observers for
+	arrays.
+	* testsuite/20_util/shared_ptr/observers/array_neg.cc: New test.
+
 2016-11-13  Ville Voutilainen  <ville.voutilainen@gmail.com>
 
 	Implement P0403R1, Literal suffixes for basic_string_view.
diff --git a/libstdc++-v3/doc/html/manual/status.html b/libstdc++-v3/doc/html/manual/status.html
index 554d519..08c9ad0 100644
--- a/libstdc++-v3/doc/html/manual/status.html
+++ b/libstdc++-v3/doc/html/manual/status.html
@@ -565,11 +565,11 @@ Feature-testing recommendations for C++</a>.
 	<a class="link" href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0220r1.html" target="_top">
 	P0220R1
 	</a>
-      </td><td align="center"> 7 </td><td align="left"> <code class="code">__cpp_lib_apply &gt;= 201603</code> </td></tr><tr bgcolor="#C8B0B0"><td align="left"> Library Fundamentals V1 TS Components: <code class="code">shared_ptr&lt;T[]&gt;</code> </td><td align="left">
+      </td><td align="center"> 7 </td><td align="left"> <code class="code">__cpp_lib_apply &gt;= 201603</code> </td></tr><tr><td align="left"> Library Fundamentals V1 TS Components: <code class="code">shared_ptr&lt;T[]&gt;</code> </td><td align="left">
 	<a class="link" href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0220r1.html" target="_top">
 	P0220R1
 	</a>
-      </td><td align="center"> No </td><td align="left"> <code class="code">__cpp_lib_shared_ptr_arrays &gt;= 201603</code> </td></tr><tr><td align="left"> Library Fundamentals V1 TS Components: Searchers </td><td align="left">
+      </td><td align="center"> 7 </td><td align="left"> <code class="code">__cpp_lib_shared_ptr_arrays &gt;= 201603</code> </td></tr><tr><td align="left"> Library Fundamentals V1 TS Components: Searchers </td><td align="left">
 	<a class="link" href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0220r1.html" target="_top">
 	P0220R1
 	</a>
diff --git a/libstdc++-v3/doc/xml/manual/status_cxx2017.xml b/libstdc++-v3/doc/xml/manual/status_cxx2017.xml
index d008bd9e..dbb26c8 100644
--- a/libstdc++-v3/doc/xml/manual/status_cxx2017.xml
+++ b/libstdc++-v3/doc/xml/manual/status_cxx2017.xml
@@ -158,14 +158,13 @@ Feature-testing recommendations for C++</link>.
     </row>
 
     <row>
-      <?dbhtml bgcolor="#C8B0B0" ?>
       <entry> Library Fundamentals V1 TS Components: <code>shared_ptr&lt;T[]&gt;</code> </entry>
       <entry>
 	<link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0220r1.html">
 	P0220R1
 	</link>
       </entry>
-      <entry align="center"> No </entry>
+      <entry align="center"> 7 </entry>
       <entry> <code>__cpp_lib_shared_ptr_arrays >= 201603</code> </entry>
     </row>
 
diff --git a/libstdc++-v3/include/bits/shared_ptr.h b/libstdc++-v3/include/bits/shared_ptr.h
index e562a42..cbe4144 100644
--- a/libstdc++-v3/include/bits/shared_ptr.h
+++ b/libstdc++-v3/include/bits/shared_ptr.h
@@ -277,6 +277,16 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 	shared_ptr(unique_ptr<_Yp, _Del>&& __r)
 	: __shared_ptr<_Tp>(std::move(__r)) { }
 
+#if __cplusplus <= 201402L && _GLIBCXX_USE_DEPRECATED
+      // This non-standard constructor exists to support conversions that
+      // were possible in C++11 and C++14 but are ill-formed in C++17.
+      // If an exception is thrown this constructor has no effect.
+      template<typename _Yp, typename _Del,
+		_Constructible<unique_ptr<_Yp, _Del>, __sp_array_delete>* = 0>
+	shared_ptr(unique_ptr<_Yp, _Del>&& __r)
+	: __shared_ptr<_Tp>(std::move(__r), __sp_array_delete()) { }
+#endif
+
       /**
        *  @brief  Construct an empty %shared_ptr.
        *  @post   use_count() == 0 && get() == nullptr
diff --git a/libstdc++-v3/include/bits/shared_ptr_base.h b/libstdc++-v3/include/bits/shared_ptr_base.h
index 5e344b8..953aa87 100644
--- a/libstdc++-v3/include/bits/shared_ptr_base.h
+++ b/libstdc++-v3/include/bits/shared_ptr_base.h
@@ -559,6 +559,12 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       _Impl _M_impl;
     };
 
+  // The default deleter for shared_ptr<T[]> and shared_ptr<T[N]>.
+  struct __sp_array_delete
+  {
+    template<typename _Yp>
+      void operator()(_Yp* __p) const { delete[] __p; }
+  };
 
   template<_Lock_policy _Lp>
     class __shared_count
@@ -582,6 +588,16 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 	    }
 	}
 
+      template<typename _Ptr>
+	__shared_count(_Ptr __p, /* is_array = */ false_type)
+	: __shared_count(__p)
+	{ }
+
+      template<typename _Ptr>
+	__shared_count(_Ptr __p, /* is_array = */ true_type)
+	: __shared_count(__p, __sp_array_delete{}, allocator<void>())
+	{ }
+
       template<typename _Ptr, typename _Deleter>
 	__shared_count(_Ptr __p, _Deleter __d)
 	: __shared_count(__p, std::move(__d), allocator<void>())
@@ -848,8 +864,12 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 	  _M_pi = nullptr;
     }
 
-  // Helper traits for shared_ptr
+#define __cpp_lib_shared_ptr_arrays 201603
+
+  // Helper traits for shared_ptr of array:
 
+  // A pointer type Y* is said to be compatible with a pointer type T* when
+  // either Y* is convertible to T* or Y is U[N] and T is U cv [].
   template<typename _Yp_ptr, typename _Tp_ptr>
     struct __sp_compatible_with
     : false_type
@@ -860,17 +880,161 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     : is_convertible<_Yp*, _Tp*>::type
     { };
 
+  template<typename _Up, size_t _Nm>
+    struct __sp_compatible_with<_Up(*)[_Nm], _Up(*)[]>
+    : true_type
+    { };
+
+  template<typename _Up, size_t _Nm>
+    struct __sp_compatible_with<_Up(*)[_Nm], const _Up(*)[]>
+    : true_type
+    { };
+
+  template<typename _Up, size_t _Nm>
+    struct __sp_compatible_with<_Up(*)[_Nm], volatile _Up(*)[]>
+    : true_type
+    { };
+
+  template<typename _Up, size_t _Nm>
+    struct __sp_compatible_with<_Up(*)[_Nm], const volatile _Up(*)[]>
+    : true_type
+    { };
+
+  // Test conversion from Y(*)[N] to U(*)[N] without forming invalid type Y[N].
+  template<typename _Up, size_t _Nm, typename _Yp, typename = void>
+    struct __sp_is_constructible_arrN
+    : false_type
+    { };
+
+  template<typename _Up, size_t _Nm, typename _Yp>
+    struct __sp_is_constructible_arrN<_Up, _Nm, _Yp, __void_t<_Yp[_Nm]>>
+    : is_convertible<_Yp(*)[_Nm], _Up(*)[_Nm]>::type
+    { };
+
+  // Test conversion from Y(*)[] to U(*)[] without forming invalid type Y[].
+  template<typename _Up, typename _Yp, typename = void>
+    struct __sp_is_constructible_arr
+    : false_type
+    { };
+
+  template<typename _Up, typename _Yp>
+    struct __sp_is_constructible_arr<_Up, _Yp, __void_t<_Yp[]>>
+    : is_convertible<_Yp(*)[], _Up(*)[]>::type
+    { };
+
+  // Trait to check if shared_ptr<T> can be constructed from Y*.
+  template<typename _Tp, typename _Yp>
+    struct __sp_is_constructible;
+
+  // When T is U[N], Y(*)[N] shall be convertible to T*;
+  template<typename _Up, size_t _Nm, typename _Yp>
+    struct __sp_is_constructible<_Up[_Nm], _Yp>
+    : __sp_is_constructible_arrN<_Up, _Nm, _Yp>::type
+    { };
+
+  // when T is U[], Y(*)[] shall be convertible to T*;
+  template<typename _Up, typename _Yp>
+    struct __sp_is_constructible<_Up[], _Yp>
+    : __sp_is_constructible_arr<_Up, _Yp>::type
+    { };
+
+  // otherwise, Y* shall be convertible to T*.
+  template<typename _Tp, typename _Yp>
+    struct __sp_is_constructible
+    : is_convertible<_Yp*, _Tp*>::type
+    { };
+
+
+  // Define operator* and operator-> for shared_ptr<T>.
+  template<typename _Tp, _Lock_policy _Lp,
+	   bool = is_array<_Tp>::value, bool = is_void<_Tp>::value>
+    class __shared_ptr_access
+    {
+    public:
+      using element_type = _Tp;
+
+      element_type&
+      operator*() const noexcept
+      {
+	__glibcxx_assert(_M_get() != nullptr);
+	return *_M_get();
+      }
+
+      element_type*
+      operator->() const noexcept
+      {
+	_GLIBCXX_DEBUG_PEDASSERT(_M_get() != nullptr);
+	return _M_get();
+      }
+
+    private:
+      element_type*
+      _M_get() const noexcept
+      { return static_cast<const __shared_ptr<_Tp, _Lp>*>(this)->get(); }
+    };
+
+  // Define operator-> for shared_ptr<cv void>.
   template<typename _Tp, _Lock_policy _Lp>
-    class __shared_ptr
+    class __shared_ptr_access<_Tp, _Lp, false, true>
     {
     public:
       using element_type = _Tp;
 
+      element_type*
+      operator->() const noexcept
+      {
+	_GLIBCXX_DEBUG_PEDASSERT(_M_get() != nullptr);
+	return static_cast<const __shared_ptr<_Tp, _Lp>*>(this)->get();
+      }
+    };
+
+  // Define operator[] for shared_ptr<T[]> and shared_ptr<T[N]>.
+  template<typename _Tp, _Lock_policy _Lp>
+    class __shared_ptr_access<_Tp, _Lp, true, false>
+    {
+    public:
+      using element_type = typename remove_extent<_Tp>::type;
+
+#if __cplusplus <= 201402L
+      [[__deprecated__("shared_ptr<T[]>::operator* is absent from C++17")]]
+      element_type&
+      operator*() const noexcept
+      {
+	__glibcxx_assert(_M_ptr != nullptr);
+	return *_M_get();
+      }
+
+      [[__deprecated__("shared_ptr<T[]>::operator-> is absent from C++17")]]
+      element_type*
+      operator->() const noexcept
+      {
+	_GLIBCXX_DEBUG_PEDASSERT(_M_get() != nullptr);
+	return _M_get();
+      }
+#endif
+
+      element_type&
+      operator[](ptrdiff_t __i) const
+      {
+	__glibcxx_assert(_M_get() != nullptr);
+	__glibcxx_assert(!extent<_Tp>::value || __i < extent<_Tp>::value);
+	return _M_get()[__i];
+      }
+
     private:
-      // Trait to check if shared_ptr<T> can be constructed from Y*.
-      template<typename _Tp1, typename _Yp>
-	using __sp_is_constructible = is_convertible<_Yp*, _Tp1*>;
+      element_type*
+      _M_get() const noexcept
+      { return static_cast<const __shared_ptr<_Tp, _Lp>*>(this)->get(); }
+    };
 
+  template<typename _Tp, _Lock_policy _Lp>
+    class __shared_ptr
+    : public __shared_ptr_access<_Tp, _Lp>
+    {
+    public:
+      using element_type = typename remove_extent<_Tp>::type;
+
+    private:
       // Constraint for taking ownership of a pointer of type _Yp*:
       template<typename _Yp>
 	using _SafeConv
@@ -888,9 +1052,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       // Constraint for construction from unique_ptr:
       template<typename _Yp, typename _Del, typename _Res = void,
 	       typename _Ptr = typename unique_ptr<_Yp, _Del>::pointer>
-	using _UniqCompatible = typename enable_if<
-	  is_convertible<_Ptr, element_type*>::value
-	  , _Res>::type;
+	using _UniqCompatible = typename enable_if<__and_<
+	  __sp_compatible_with<_Yp*, _Tp*>, is_convertible<_Ptr, element_type*>
+	  >::value, _Res>::type;
 
       // Constraint for assignment from unique_ptr:
       template<typename _Yp, typename _Del>
@@ -909,7 +1073,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       template<typename _Yp, typename = _SafeConv<_Yp>>
 	explicit
 	__shared_ptr(_Yp* __p)
-	: _M_ptr(__p), _M_refcount(__p)
+	: _M_ptr(__p), _M_refcount(__p, typename is_array<_Tp>::type())
 	{
 	  static_assert( !is_void<_Yp>::value, "incomplete type" );
 	  static_assert( sizeof(_Yp) > 0, "incomplete type" );
@@ -995,6 +1159,24 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 	  _M_enable_shared_from_this_with(__raw);
 	}
 
+#if __cplusplus <= 201402L && _GLIBCXX_USE_DEPRECATED
+    protected:
+      // If an exception is thrown this constructor has no effect.
+      template<typename _Tp1, typename _Del,
+	       typename enable_if<__and_<
+		 __not_<is_array<_Tp>>, is_array<_Tp1>,
+	         is_convertible<typename unique_ptr<_Tp1, _Del>::pointer, _Tp*>
+	       >::value, bool>::type = true>
+	__shared_ptr(unique_ptr<_Tp1, _Del>&& __r, __sp_array_delete)
+	: _M_ptr(__r.get()), _M_refcount()
+	{
+	  auto __raw = _S_raw_ptr(__r.get());
+	  _M_refcount = __shared_count<_Lp>(std::move(__r));
+	  _M_enable_shared_from_this_with(__raw);
+	}
+    public:
+#endif
+
 #if _GLIBCXX_USE_DEPRECATED
       // Postcondition: use_count() == 1 and __r.get() == 0
       template<typename _Yp, typename = _Compatible<_Yp>>
@@ -1068,21 +1250,6 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 	reset(_Yp* __p, _Deleter __d, _Alloc __a)
         { __shared_ptr(__p, __d, std::move(__a)).swap(*this); }
 
-      // Allow class instantiation when _Tp is [cv-qual] void.
-      typename std::add_lvalue_reference<element_type>::type
-      operator*() const noexcept
-      {
-	__glibcxx_assert(_M_ptr != 0);
-	return *_M_ptr;
-      }
-
-      element_type*
-      operator->() const noexcept
-      {
-	_GLIBCXX_DEBUG_PEDASSERT(_M_ptr != 0);
-	return _M_ptr;
-      }
-
       element_type*
       get() const noexcept
       { return _M_ptr; }
@@ -1193,7 +1360,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
       template<typename _Yp>
 	struct __has_esft_base<_Yp, __void_t<__esft_base_t<_Yp>>>
-	: true_type { };
+	: __not_<is_array<_Tp>> { }; // No enable shared_from_this for arrays
 
       template<typename _Yp>
 	typename enable_if<__has_esft_base<_Yp>::value>::type
@@ -1428,7 +1595,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 	using _Assignable = _Compatible<_Yp, __weak_ptr&>;
 
     public:
-      using element_type = _Tp;
+      using element_type = typename remove_extent<_Tp>::type;
 
       constexpr __weak_ptr() noexcept
       : _M_ptr(nullptr), _M_refcount()
diff --git a/libstdc++-v3/include/experimental/bits/shared_ptr.h b/libstdc++-v3/include/experimental/bits/shared_ptr.h
index e8c533e..8a1fc52 100644
--- a/libstdc++-v3/include/experimental/bits/shared_ptr.h
+++ b/libstdc++-v3/include/experimental/bits/shared_ptr.h
@@ -46,665 +46,20 @@ namespace experimental
 inline namespace fundamentals_v2
 {
 _GLIBCXX_BEGIN_NAMESPACE_VERSION
-  template<typename _Tp> class enable_shared_from_this;
-_GLIBCXX_END_NAMESPACE_VERSION
-} // namespace fundamentals_v2
-} // namespace experimental
-
-#define __cpp_lib_experimental_shared_ptr_arrays 201406
-
-_GLIBCXX_BEGIN_NAMESPACE_VERSION
-
-  /*
-   * The specification of std::experimental::shared_ptr is slightly different
-   * to std::shared_ptr (specifically in terms of "compatible" pointers) so
-   * to implement std::experimental::shared_ptr without too much duplication
-   * we make it derive from a partial specialization of std::__shared_ptr
-   * using a special tag type, __libfund_v1.
-   *
-   * There are two partial specializations for the tag type, supporting the
-   * different interfaces of the array and non-array forms.
-  */
-
-  template <typename _Tp, bool = is_array<_Tp>::value>
-    struct __libfund_v1 { using type = _Tp; };
-
-  // Partial specialization for base class of experimental::shared_ptr<T>
-  // (i.e. the non-array form of experimental::shared_ptr)
-  template<typename _Tp, _Lock_policy _Lp>
-    class __shared_ptr<__libfund_v1<_Tp, false>, _Lp>
-    : private __shared_ptr<_Tp, _Lp>
-    {
-      // For non-arrays, Y* is compatible with T* if Y* is convertible to T*.
-      template<typename _Yp, typename _Res = void>
-	using _Compatible
-	  = enable_if_t<experimental::is_convertible_v<_Yp*, _Tp*>, _Res>;
-
-      template<typename _Yp, typename _Del,
-	       typename _Ptr = typename unique_ptr<_Yp, _Del>::pointer,
-	       typename _Res = void>
-	using _UniqCompatible = enable_if_t<
-	  experimental::is_convertible_v<_Yp*, _Tp*>
-	  && experimental::is_convertible_v<_Ptr, _Tp*>,
-	  _Res>;
-
-      using _Base_type = __shared_ptr<_Tp>;
-
-      _Base_type&  _M_get_base() { return *this; }
-      const _Base_type&  _M_get_base() const { return *this; }
-
-    public:
-      using element_type = _Tp;
-
-      constexpr __shared_ptr() noexcept = default;
-
-      template<typename _Tp1, typename = _Compatible<_Tp1>>
-	explicit
-	__shared_ptr(_Tp1* __p)
-	: _Base_type(__p)
-	{ }
-
-      template<typename _Tp1, typename _Deleter, typename = _Compatible<_Tp1>>
-	__shared_ptr(_Tp1* __p, _Deleter __d)
-	: _Base_type(__p, __d)
-	{ }
-
-      template<typename _Tp1, typename _Deleter, typename _Alloc,
-	       typename = _Compatible<_Tp1>>
-	__shared_ptr(_Tp1* __p, _Deleter __d, _Alloc __a)
-	: _Base_type(__p, __d, __a)
-	{ }
-
-      template<typename _Deleter>
-	__shared_ptr(nullptr_t __p, _Deleter __d)
-	: _Base_type(__p, __d)
-	{ }
-
-      template<typename _Deleter, typename _Alloc>
-	__shared_ptr(nullptr_t __p, _Deleter __d, _Alloc __a)
-	: _Base_type(__p, __d, __a)
-	{ }
-
-      template<typename _Tp1>
-	__shared_ptr(const __shared_ptr<__libfund_v1<_Tp1>, _Lp>& __r,
-		     element_type* __p) noexcept
-	: _Base_type(__r._M_get_base(), __p)
-	{ }
-
-      __shared_ptr(const __shared_ptr&) noexcept = default;
-      __shared_ptr(__shared_ptr&&) noexcept = default;
-      __shared_ptr& operator=(const __shared_ptr&) noexcept = default;
-      __shared_ptr& operator=(__shared_ptr&&) noexcept = default;
-      ~__shared_ptr() = default;
-
-      template<typename _Tp1, typename = _Compatible<_Tp1>>
-	__shared_ptr(const __shared_ptr<__libfund_v1<_Tp1>, _Lp>& __r) noexcept
-	: _Base_type(__r._M_get_base())
-	{ }
-
-      template<typename _Tp1, typename = _Compatible<_Tp1>>
-	__shared_ptr(__shared_ptr<__libfund_v1<_Tp1>, _Lp>&& __r) noexcept
-	: _Base_type(std::move((__r._M_get_base())))
-	{ }
-
-      template<typename _Tp1, typename = _Compatible<_Tp1>>
-	explicit
-	__shared_ptr(const __weak_ptr<__libfund_v1<_Tp1>, _Lp>& __r)
-	: _Base_type(__r._M_get_base())
-	{ }
-
-      template<typename _Tp1, typename _Del,
-	       typename = _UniqCompatible<_Tp1, _Del>>
-	__shared_ptr(unique_ptr<_Tp1, _Del>&& __r)
-	: _Base_type(std::move(__r))
-	{ }
-
-#if _GLIBCXX_USE_DEPRECATED
-      // Postcondition: use_count() == 1 and __r.get() == 0
-      template<typename _Tp1, typename = _Compatible<_Tp1>>
-	__shared_ptr(std::auto_ptr<_Tp1>&& __r)
-        : _Base_type(std::move(__r))
-	{ }
-#endif
-
-      constexpr __shared_ptr(nullptr_t) noexcept : __shared_ptr() { }
-
-      // reset
-      void
-      reset() noexcept
-      { __shared_ptr(nullptr).swap(*this); }
-
-      template<typename _Tp1>
-	_Compatible<_Tp1>
-	reset(_Tp1* __p)
-	{
-	  _GLIBCXX_DEBUG_ASSERT(__p == 0 || __p != get());
-	  __shared_ptr(__p).swap(*this);
-	}
-
-      template<typename _Tp1, typename _Deleter>
-	_Compatible<_Tp1>
-	reset(_Tp1* __p, _Deleter __d)
-	{ __shared_ptr(__p, __d).swap(*this); }
-
-      template<typename _Tp1, typename _Deleter, typename _Alloc>
-	_Compatible<_Tp1>
-	reset(_Tp1* __p, _Deleter __d, _Alloc __a)
-	{ __shared_ptr(__p, __d, std::move(__a)).swap(*this); }
-
-      using _Base_type::operator*;
-      using _Base_type::operator->;
-
-      template<typename _Tp1>
-	_Compatible<_Tp1, __shared_ptr&>
-	operator=(const __shared_ptr<__libfund_v1<_Tp1>, _Lp>& __r) noexcept
-	{
-	  _Base_type::operator=(__r._M_get_base());
-	  return *this;
-	}
-
-      template<class _Tp1>
-	_Compatible<_Tp1, __shared_ptr&>
-	operator=(__shared_ptr<__libfund_v1<_Tp1>, _Lp>&& __r) noexcept
-	{
-	  _Base_type::operator=(std::move(__r._M_get_base()));
-	  return *this;
-	}
-
-      template<typename _Tp1, typename _Del>
-	_UniqCompatible<_Tp1, _Del, __shared_ptr&>
-	operator=(unique_ptr<_Tp1, _Del>&& __r)
-	{
-	  _Base_type::operator=(std::move(__r));
-	  return *this;
-	}
-
-#if _GLIBCXX_USE_DEPRECATED
-      template<typename _Tp1>
-	_Compatible<_Tp1, __shared_ptr&>
-	operator=(std::auto_ptr<_Tp1>&& __r)
-	{
-	  _Base_type::operator=(std::move(__r));
-	  return *this;
-	}
-#endif
-
-      void
-      swap(__shared_ptr& __other) noexcept
-      { _Base_type::swap(__other); }
-
-      template<typename _Tp1>
-	bool
-	owner_before(__shared_ptr<__libfund_v1<_Tp1>, _Lp> const& __rhs) const
-	{ return _Base_type::owner_before(__rhs._M_get_base()); }
-
-      template<typename _Tp1>
-	bool
-	owner_before(__weak_ptr<__libfund_v1<_Tp1>, _Lp> const& __rhs) const
-	{ return _Base_type::owner_before(__rhs._M_get_base()); }
-
-      using _Base_type::operator bool;
-      using _Base_type::get;
-      using _Base_type::unique;
-      using _Base_type::use_count;
-
-    protected:
-
-      // make_shared not yet support for shared_ptr_arrays
-      //template<typename _Alloc, typename... _Args>
-      //  __shared_ptr(_Sp_make_shared_tag __tag, const _Alloc& __a,
-      //	             _Args&&... __args)
-      //	: _M_ptr(), _M_refcount(__tag, (_Tp*)0, __a,
-      //	                        std::forward<_Args>(__args)...)
-      //	{
-      //	  void* __p = _M_refcount._M_get_deleter(typeid(__tag));
-      //	  _M_ptr = static_cast<_Tp*>(__p);
-      //	}
-
-      // __weak_ptr::lock()
-      __shared_ptr(const __weak_ptr<__libfund_v1<_Tp>, _Lp>& __r,
-		   std::nothrow_t)
-      : _Base_type(__r._M_get_base(), std::nothrow)
-      { }
-
-    private:
-      template<typename _Tp1, _Lock_policy _Lp1> friend class __weak_ptr;
-      template<typename _Tp1, _Lock_policy _Lp1> friend class __shared_ptr;
-
-      // TODO
-      template<typename _Del, typename _Tp1, _Lock_policy _Lp1>
-	friend _Del* get_deleter(const __shared_ptr<_Tp1, _Lp1>&) noexcept;
-    };
-
-  // Helper traits for shared_ptr of array:
 
-  // Trait that tests if Y* is compatible with T*, for shared_ptr purposes.
-  template<typename _Yp, typename _Tp>
-    struct __sp_compatible
-    : is_convertible<_Yp*, _Tp*>::type
-    { };
+  // 8.2.1
 
-  template<size_t _Nm, typename _Tp>
-    struct __sp_compatible<_Tp[_Nm], _Tp[]>
-    : true_type
-    { };
-
-  template<size_t _Nm, typename _Tp>
-    struct __sp_compatible<_Tp[_Nm], const _Tp[]>
-    : true_type
-    { };
+  template<typename _Tp> class shared_ptr;
+  template<typename _Tp> class weak_ptr;
+  template<typename _Tp> class enable_shared_from_this;
 
   template<typename _Yp, typename _Tp>
     constexpr bool __sp_compatible_v
-      = __sp_compatible<_Yp, _Tp>::value;
-
-  // Test conversion from Y(*)[N] to U(*)[N] without forming invalid type Y[N].
-  template<typename _Up, size_t _Nm, typename _Yp, typename = void>
-    struct __sp_is_constructible_arrN
-    : false_type
-    { };
-
-  template<typename _Up, size_t _Nm, typename _Yp>
-    struct __sp_is_constructible_arrN<_Up, _Nm, _Yp, __void_t<_Yp[_Nm]>>
-    : is_convertible<_Yp(*)[_Nm], _Up(*)[_Nm]>::type
-    { };
-
-  // Test conversion from Y(*)[] to U(*)[] without forming invalid type Y[].
-  template<typename _Up, typename _Yp, typename = void>
-    struct __sp_is_constructible_arr
-    : false_type
-    { };
-
-  template<typename _Up, typename _Yp>
-    struct __sp_is_constructible_arr<_Up, _Yp, __void_t<_Yp[]>>
-    : is_convertible<_Yp(*)[], _Up(*)[]>::type
-    { };
-
-  // Trait to check if shared_ptr<T> can be constructed from Y*.
-  template<typename _Tp, typename _Yp>
-    struct __sp_is_constructible;
-
-  // When T is U[N], Y(*)[N] shall be convertible to T*;
-  template<typename _Up, size_t _Nm, typename _Yp>
-    struct __sp_is_constructible<_Up[_Nm], _Yp>
-    : __sp_is_constructible_arrN<_Up, _Nm, _Yp>::type
-    { };
-
-  // when T is U[], Y(*)[] shall be convertible to T*;
-  template<typename _Up, typename _Yp>
-    struct __sp_is_constructible<_Up[], _Yp>
-    : __sp_is_constructible_arr<_Up, _Yp>::type
-    { };
-
-  // otherwise, Y* shall be convertible to T*.
-  template<typename _Tp, typename _Yp>
-    struct __sp_is_constructible
-    : is_convertible<_Yp*, _Tp*>::type
-    { };
+      = std::__sp_compatible_with<_Yp*, _Tp*>::value;
 
   template<typename _Tp, typename _Yp>
     constexpr bool __sp_is_constructible_v
-      = __sp_is_constructible<_Tp, _Yp>::value;
-
-
-  // Partial specialization for base class of experimental::shared_ptr<T[N]>
-  // and experimental::shared_ptr<T[]> (i.e. the array forms).
-  template<typename _Tp, _Lock_policy _Lp>
-    class __shared_ptr<__libfund_v1<_Tp, true>, _Lp>
-    : private __shared_ptr<remove_extent_t<_Tp>, _Lp>
-    {
-    public:
-      using element_type = remove_extent_t<_Tp>;
-
-    private:
-      struct _Array_deleter
-      {
-	void
-	operator()(element_type const *__p) const
-	{ delete [] __p; }
-      };
-
-      // Constraint for constructing/resetting with a pointer of type _Yp*:
-      template<typename _Yp>
-	using _SafeConv = enable_if_t<__sp_is_constructible_v<_Tp, _Yp>>;
-
-      // Constraint for constructing/assigning from smart_pointer<_Tp1>:
-      template<typename _Tp1, typename _Res = void>
-	using _Compatible = enable_if_t<__sp_compatible_v<_Tp1, _Tp>, _Res>;
-
-      // Constraint for constructing/assigning from unique_ptr<_Tp1, _Del>:
-      template<typename _Tp1, typename _Del,
-	       typename _Ptr = typename unique_ptr<_Tp1, _Del>::pointer,
-	       typename _Res = void>
-	using _UniqCompatible = enable_if_t<
-	  __sp_compatible_v<_Tp1, _Tp>
-	  && experimental::is_convertible_v<_Ptr, element_type*>,
-	  _Res>;
-
-      using _Base_type = __shared_ptr<element_type>;
-
-      _Base_type&  _M_get_base() { return *this; }
-      const _Base_type&  _M_get_base() const { return *this; }
-
-    public:
-      constexpr __shared_ptr() noexcept
-      : _Base_type()
-      { }
-
-      template<typename _Tp1, typename = _SafeConv<_Tp1>>
-	explicit
-	__shared_ptr(_Tp1* __p)
-	: _Base_type(__p, _Array_deleter())
-	{ }
-
-      template<typename _Tp1, typename _Deleter, typename = _SafeConv<_Tp1>>
-	__shared_ptr(_Tp1* __p, _Deleter __d)
-	: _Base_type(__p, __d)
-	{ }
-
-      template<typename _Tp1, typename _Deleter, typename _Alloc,
-	       typename = _SafeConv<_Tp1>>
-	__shared_ptr(_Tp1* __p, _Deleter __d, _Alloc __a)
-	: _Base_type(__p, __d, __a)
-	{ }
-
-      template<typename _Deleter>
-	__shared_ptr(nullptr_t __p, _Deleter __d)
-	: _Base_type(__p, __d)
-	{ }
-
-      template<typename _Deleter, typename _Alloc>
-	__shared_ptr(nullptr_t __p, _Deleter __d, _Alloc __a)
-	: _Base_type(__p, __d, __a)
-	{ }
-
-      template<typename _Tp1>
-	__shared_ptr(const __shared_ptr<__libfund_v1<_Tp1>, _Lp>& __r,
-		     element_type* __p) noexcept
-	: _Base_type(__r._M_get_base(), __p)
-	{ }
-
-      __shared_ptr(const __shared_ptr&) noexcept = default;
-      __shared_ptr(__shared_ptr&&) noexcept = default;
-      __shared_ptr& operator=(const __shared_ptr&) noexcept = default;
-      __shared_ptr& operator=(__shared_ptr&&) noexcept = default;
-      ~__shared_ptr() = default;
-
-      template<typename _Tp1, typename = _Compatible<_Tp1>>
-	__shared_ptr(const __shared_ptr<__libfund_v1<_Tp1>, _Lp>& __r) noexcept
-	: _Base_type(__r._M_get_base())
-	{ }
-
-      template<typename _Tp1, typename = _Compatible<_Tp1>>
-	__shared_ptr(__shared_ptr<__libfund_v1<_Tp1>, _Lp>&& __r) noexcept
-	: _Base_type(std::move((__r._M_get_base())))
-	{ }
-
-      template<typename _Tp1, typename = _Compatible<_Tp1>>
-	explicit
-	__shared_ptr(const __weak_ptr<__libfund_v1<_Tp1>, _Lp>& __r)
-	: _Base_type(__r._M_get_base())
-	{ }
-
-      template<typename _Tp1, typename _Del,
-	       typename = _UniqCompatible<_Tp1, _Del>>
-	__shared_ptr(unique_ptr<_Tp1, _Del>&& __r)
-	: _Base_type(std::move(__r))
-	{ }
-
-#if _GLIBCXX_USE_DEPRECATED
-      // Postcondition: use_count() == 1 and __r.get() == 0
-      template<typename _Tp1, typename = _Compatible<_Tp1>>
-	__shared_ptr(auto_ptr<_Tp1>&& __r)
-        : _Base_type(std::move(__r))
-	{ }
-#endif
-
-      constexpr __shared_ptr(nullptr_t) noexcept : __shared_ptr() { }
-
-      // reset
-      void
-      reset() noexcept
-      { __shared_ptr(nullptr).swap(*this); }
-
-      template<typename _Tp1>
-	_SafeConv<_Tp1>
-	reset(_Tp1* __p)
-	{
-	  _GLIBCXX_DEBUG_ASSERT(__p == 0 || __p != get());
-	  __shared_ptr(__p, _Array_deleter()).swap(*this);
-	}
-
-      template<typename _Tp1, typename _Deleter>
-	_SafeConv<_Tp1>
-	reset(_Tp1* __p, _Deleter __d)
-	{ __shared_ptr(__p, __d).swap(*this); }
-
-      template<typename _Tp1, typename _Deleter, typename _Alloc>
-	_SafeConv<_Tp1>
-	reset(_Tp1* __p, _Deleter __d, _Alloc __a)
-	{ __shared_ptr(__p, __d, std::move(__a)).swap(*this); }
-
-      element_type&
-      operator[](ptrdiff_t i) const noexcept
-      {
-	_GLIBCXX_DEBUG_ASSERT(get() != 0 && i >= 0);
-	return get()[i];
-      }
-
-      template<typename _Tp1>
-	_Compatible<_Tp1, __shared_ptr&>
-	operator=(const __shared_ptr<__libfund_v1<_Tp1>, _Lp>& __r) noexcept
-	{
-	  _Base_type::operator=(__r._M_get_base());
-	  return *this;
-	}
-
-      template<class _Tp1>
-	_Compatible<_Tp1, __shared_ptr&>
-	operator=(__shared_ptr<__libfund_v1<_Tp1>, _Lp>&& __r) noexcept
-	{
-	  _Base_type::operator=(std::move(__r._M_get_base()));
-	  return *this;
-	}
-
-      template<typename _Tp1, typename _Del>
-	_UniqCompatible<_Tp1, _Del, __shared_ptr&>
-	operator=(unique_ptr<_Tp1, _Del>&& __r)
-	{
-	  _Base_type::operator=(std::move(__r));
-	  return *this;
-	}
-
-#if _GLIBCXX_USE_DEPRECATED
-      template<typename _Tp1>
-	_Compatible<_Tp1, __shared_ptr&>
-	operator=(auto_ptr<_Tp1>&& __r)
-	{
-	  _Base_type::operator=(std::move(__r));
-	  return *this;
-	}
-#endif
-
-      void
-      swap(__shared_ptr& __other) noexcept
-      { _Base_type::swap(__other); }
-
-      template<typename _Tp1>
-	bool
-	owner_before(__shared_ptr<__libfund_v1<_Tp1>, _Lp> const& __rhs) const
-	{ return _Base_type::owner_before(__rhs._M_get_base()); }
-
-      template<typename _Tp1>
-	bool
-	owner_before(__weak_ptr<__libfund_v1<_Tp1>, _Lp> const& __rhs) const
-	{ return _Base_type::owner_before(__rhs._M_get_base()); }
-
-      using _Base_type::operator bool;
-      using _Base_type::get;
-      using _Base_type::unique;
-      using _Base_type::use_count;
-
-    protected:
-
-      // make_shared not yet support for shared_ptr_arrays
-      //template<typename _Alloc, typename... _Args>
-      //  __shared_ptr(_Sp_make_shared_tag __tag, const _Alloc& __a,
-      //	             _Args&&... __args)
-      //	: _M_ptr(), _M_refcount(__tag, (_Tp*)0, __a,
-      //	                        std::forward<_Args>(__args)...)
-      //	{
-      //	  void* __p = _M_refcount._M_get_deleter(typeid(__tag));
-      //	  _M_ptr = static_cast<_Tp*>(__p);
-      //	}
-
-      // __weak_ptr::lock()
-      __shared_ptr(const __weak_ptr<__libfund_v1<_Tp>, _Lp>& __r,
-		   std::nothrow_t)
-      : _Base_type(__r._M_get_base(), std::nothrow)
-      { }
-
-    private:
-      template<typename _Tp1, _Lock_policy _Lp1> friend class __weak_ptr;
-      template<typename _Tp1, _Lock_policy _Lp1> friend class __shared_ptr;
-
-      // TODO
-      template<typename _Del, typename _Tp1, _Lock_policy _Lp1>
-	friend _Del* get_deleter(const __shared_ptr<_Tp1, _Lp1>&) noexcept;
-    };
-
-  // weak_ptr specialization for __shared_ptr array
-  template<typename _Tp, _Lock_policy _Lp>
-    class __weak_ptr<__libfund_v1<_Tp>, _Lp>
-    : __weak_ptr<remove_extent_t<_Tp>, _Lp>
-    {
-      template<typename _Tp1, typename _Res = void>
-	using _Compatible
-	  = enable_if_t<__sp_compatible_v<_Tp1, _Tp>, _Res>;
-
-      using _Base_type = __weak_ptr<remove_extent_t<_Tp>>;
-
-      _Base_type&  _M_get_base() { return *this; }
-      const _Base_type&  _M_get_base() const { return *this; }
-
-    public:
-      using element_type = remove_extent_t<_Tp>;
-
-      constexpr __weak_ptr() noexcept
-      : _Base_type()
-      { }
-
-      __weak_ptr(const __weak_ptr&) noexcept = default;
-
-      ~__weak_ptr() = default;
-
-      template<typename _Tp1, typename = _Compatible<_Tp1>>
-	__weak_ptr(const __weak_ptr<__libfund_v1<_Tp1>, _Lp>& __r) noexcept
-	: _Base_type(__r._M_get_base())
-	{ }
-
-      template<typename _Tp1, typename = _Compatible<_Tp1>>
-	__weak_ptr(const __shared_ptr<__libfund_v1<_Tp1>, _Lp>& __r) noexcept
-	: _Base_type(__r._M_get_base())
-	{ }
-
-      __weak_ptr(__weak_ptr&& __r) noexcept
-      : _Base_type(std::move(__r))
-      { }
-
-      template<typename _Tp1, typename = _Compatible<_Tp1>>
-	__weak_ptr(__weak_ptr<__libfund_v1<_Tp1>, _Lp>&& __r) noexcept
-	: _Base_type(std::move(__r._M_get_base()))
-	{ }
-
-      __weak_ptr&
-      operator=(const __weak_ptr& __r) noexcept = default;
-
-      template<typename _Tp1>
-	_Compatible<_Tp1, __weak_ptr&>
-	operator=(const __weak_ptr<__libfund_v1<_Tp1>, _Lp>& __r) noexcept
-	{
-	  this->_Base_type::operator=(__r._M_get_base());
-	  return *this;
-	}
-
-      template<typename _Tp1>
-	_Compatible<_Tp1, __weak_ptr&>
-	operator=(const __shared_ptr<_Tp1, _Lp>& __r) noexcept
-	{
-	  this->_Base_type::operator=(__r._M_get_base());
-	  return *this;
-	}
-
-      __weak_ptr&
-      operator=(__weak_ptr&& __r) noexcept
-      {
-	this->_Base_type::operator=(std::move(__r));
-	return *this;
-      }
-
-      template<typename _Tp1>
-	_Compatible<_Tp1, __weak_ptr&>
-	operator=(__weak_ptr<_Tp1, _Lp>&& __r) noexcept
-	{
-	  this->_Base_type::operator=(std::move(__r._M_get_base()));
-	  return *this;
-	}
-
-      void
-      swap(__weak_ptr& __other) noexcept
-      { this->_Base_type::swap(__other); }
-
-      template<typename _Tp1>
-	bool
-	owner_before(const __shared_ptr<__libfund_v1<_Tp1>, _Lp>& __rhs) const
-	{ return _Base_type::owner_before(__rhs._M_get_base()); }
-
-      template<typename _Tp1>
-	bool
-	owner_before(const __weak_ptr<__libfund_v1<_Tp1>, _Lp>& __rhs) const
-	{ return _Base_type::owner_before(__rhs._M_get_base()); }
-
-      __shared_ptr<__libfund_v1<_Tp>, _Lp>
-      lock() const noexcept  // should not be element_type
-      { return __shared_ptr<__libfund_v1<_Tp>, _Lp>(*this, std::nothrow); }
-
-      using _Base_type::use_count;
-      using _Base_type::expired;
-      using _Base_type::reset;
-
-    private:
-      // Used by __enable_shared_from_this.
-      void
-      _M_assign(element_type* __ptr,
-		const __shared_count<_Lp>& __refcount) noexcept
-      { this->_Base_type::_M_assign(__ptr, __refcount); }
-
-      template<typename _Tp1, _Lock_policy _Lp1> friend class __shared_ptr;
-      template<typename _Tp1, _Lock_policy _Lp1> friend class __weak_ptr;
-      friend class __enable_shared_from_this<_Tp, _Lp>;
-      friend class experimental::enable_shared_from_this<_Tp>;
-      friend class enable_shared_from_this<_Tp>;
-    };
-
-_GLIBCXX_END_NAMESPACE_VERSION
-
-namespace experimental
-{
-inline namespace fundamentals_v2
-{
-_GLIBCXX_BEGIN_NAMESPACE_VERSION
-
-    // 8.2.1
-
-  template<typename _Tp> class shared_ptr;
-  template<typename _Tp> class weak_ptr;
-
-  template<typename _Tp, _Lock_policy _Lp = __default_lock_policy>
-    using __shared_ptr = std::__shared_ptr<__libfund_v1<_Tp>, _Lp>;
-
-  template<typename _Tp, _Lock_policy _Lp = __default_lock_policy>
-    using __weak_ptr = std::__weak_ptr<__libfund_v1<_Tp>, _Lp>;
+      = std::__sp_is_constructible<_Tp, _Yp>::value;
 
   template<typename _Tp>
     class shared_ptr : public __shared_ptr<_Tp>
@@ -1128,16 +483,15 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     { __a.swap(__b); }
 
   /// C++14 §20.8.2.2.10
-  template<typename _Del, typename _Tp, _Lock_policy _Lp>
+  template<typename _Del, typename _Tp>
     inline _Del*
-    get_deleter(const __shared_ptr<_Tp, _Lp>& __p) noexcept
+    get_deleter(const shared_ptr<_Tp>& __p) noexcept
     { return std::get_deleter<_Del>(__p); }
 
   // C++14 §20.8.2.2.11
-  template<typename _Ch, typename _Tr, typename _Tp, _Lock_policy _Lp>
+  template<typename _Ch, typename _Tr, typename _Tp>
     inline std::basic_ostream<_Ch, _Tr>&
-    operator<<(std::basic_ostream<_Ch, _Tr>& __os,
-	       const __shared_ptr<_Tp, _Lp>& __p)
+    operator<<(std::basic_ostream<_Ch, _Tr>& __os, const shared_ptr<_Tp>& __p)
     {
       __os << __p.get();
       return __os;
diff --git a/libstdc++-v3/testsuite/20_util/shared_ptr/cons/array.cc b/libstdc++-v3/testsuite/20_util/shared_ptr/cons/array.cc
new file mode 100644
index 0000000..d56dc66
--- /dev/null
+++ b/libstdc++-v3/testsuite/20_util/shared_ptr/cons/array.cc
@@ -0,0 +1,273 @@
+// { dg-do run { target c++11 } }
+
+// Copyright (C) 2016 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+#include <memory>
+#include <testsuite_hooks.h>
+
+// C++1z 20.11.2.2.1 shared_ptr constructors [util.smartptr.shared.const]
+
+template<typename To, typename From>
+constexpr bool check()
+{
+  using std::shared_ptr;
+  using std::is_constructible;
+  return !is_constructible<shared_ptr<To>, shared_ptr<From>>::value
+    && !is_constructible<shared_ptr<To>, shared_ptr<From>&>::value;
+}
+
+static_assert( check<int, int[]>() );
+static_assert( check<int, int[2]>() );
+static_assert( check<int[2], void>() );
+static_assert( check<int[2], int>() );
+static_assert( check<int[2], int[]>() );
+static_assert( check<int[], void>() );
+static_assert( check<int[], int>() );
+
+int count = 0;
+
+struct A {
+  A() { ++count; }
+  ~A() { --count; }
+};
+
+struct B : A { };
+
+static_assert( check<A, B[2]>() );
+static_assert( check<A, B[]>() );
+static_assert( check<A[2], B>() );
+static_assert( check<A[2], B[2]>() );
+static_assert( check<A[2], B[]>() );
+static_assert( check<A[], B>() );
+static_assert( check<A[], B[2]>() );
+static_assert( check<A[], B[]>() );
+
+void
+test01()
+{
+  std::shared_ptr<A[2]> p;
+  VERIFY( p.get() == nullptr );
+  VERIFY( p.use_count() == 0 );
+  p.reset();
+  VERIFY( count == 0 );
+}
+
+void
+test02()
+{
+  std::shared_ptr<A[]> p;
+  VERIFY( p.get() == nullptr );
+  VERIFY( p.use_count() == 0 );
+  p.reset();
+  VERIFY( count == 0 );
+}
+
+void
+test03()
+{
+  std::shared_ptr<A[2]> p(nullptr);
+  VERIFY( p.get() == nullptr );
+  VERIFY( p.use_count() == 0 );
+  p.reset();
+  VERIFY( count == 0 );
+}
+
+void
+test04()
+{
+  std::shared_ptr<A[]> p(nullptr);
+  VERIFY( p.get() == nullptr );
+  VERIFY( p.use_count() == 0 );
+  p.reset();
+  VERIFY( count == 0 );
+}
+
+// Construction from pointer
+
+void
+test05()
+{
+  A * const a = nullptr;
+  std::shared_ptr<A[2]> p(a);
+  VERIFY( p.get() == nullptr );
+  VERIFY( p.use_count() == 1 );
+  p.reset();
+  VERIFY( count == 0 );
+}
+
+void
+test06()
+{
+  A * const a = nullptr;
+  std::shared_ptr<A[]> p(a);
+  VERIFY( p.get() == nullptr );
+  VERIFY( p.use_count() == 1 );
+  p.reset();
+  VERIFY( count == 0 );
+}
+
+void
+test07()
+{
+  A * const a = new A[2];
+  std::shared_ptr<A[2]> p(a);
+  VERIFY( p.get() == a );
+  VERIFY( p.use_count() == 1 );
+  p.reset();
+  VERIFY( count == 0 );
+}
+
+void
+test08()
+{
+  A * const a = new A[2];
+  std::shared_ptr<A[]> p(a);
+  VERIFY( p.get() == a );
+  VERIFY( p.use_count() == 1 );
+  p.reset();
+  VERIFY( count == 0 );
+}
+
+// Converting constrcutor
+
+void
+test09()
+{
+  A * const a = new A[2];
+  std::shared_ptr<A[2]> p(a);
+  std::shared_ptr<const A[2]> p2(p);
+  VERIFY( p2.get() == a );
+  VERIFY( p.use_count() == 2 );
+  VERIFY( p2.use_count() == 2 );
+  p.reset();
+  VERIFY( count != 0 );
+  p2.reset();
+  VERIFY( count == 0 );
+}
+
+void
+test10()
+{
+  A * const a = new A[2];
+  std::shared_ptr<A[]> p(a);
+  std::shared_ptr<const A[]> p2(p);
+  VERIFY( p2.get() == a );
+  VERIFY( p.use_count() == 2 );
+  VERIFY( p2.use_count() == 2 );
+  p.reset();
+  VERIFY( count != 0 );
+  p2.reset();
+  VERIFY( count == 0 );
+}
+
+void
+test11()
+{
+  A * const a = new A[2];
+  std::shared_ptr<A[2]> p(a);
+  std::shared_ptr<const A[]> p2(p);
+  VERIFY( p2.get() == a );
+  VERIFY( p.use_count() == 2 );
+  VERIFY( p2.use_count() == 2 );
+  p.reset();
+  VERIFY( count != 0 );
+  p2.reset();
+  VERIFY( count == 0 );
+}
+
+// Copy construction
+
+void
+test12()
+{
+  A * const a = new A[2];
+  std::shared_ptr<A[2]> p(a);
+  std::shared_ptr<A[2]> p2(p);
+  VERIFY( p2.get() == a );
+  VERIFY( p.use_count() == 2 );
+  VERIFY( p2.use_count() == 2 );
+  p.reset();
+  VERIFY( count != 0 );
+  p2.reset();
+  VERIFY( count == 0 );
+}
+
+void
+test13()
+{
+  A * const a = new A[2];
+  std::shared_ptr<A[2]> p(a);
+  std::shared_ptr<A[]> p2(p);
+  VERIFY( p2.get() == a );
+  VERIFY( p.use_count() == 2 );
+  VERIFY( p2.use_count() == 2 );
+  p.reset();
+  VERIFY( count != 0 );
+  p2.reset();
+  VERIFY( count == 0 );
+}
+
+// Move construction
+
+void
+test14()
+{
+  A * const a = new A[2];
+  std::shared_ptr<A[2]> p(a);
+  std::shared_ptr<A[2]> p2(std::move(p));
+  VERIFY( p.get() == nullptr );
+  VERIFY( p2.get() == a );
+  VERIFY( p.use_count() == 0 );
+  VERIFY( p2.use_count() == 1 );
+  p2.reset();
+  VERIFY( count == 0 );
+}
+
+void
+test15()
+{
+  A * const a = new A[2];
+  std::shared_ptr<A[2]> p(a);
+  std::shared_ptr<A[]> p2(std::move(p));
+  VERIFY( p.get() == nullptr );
+  VERIFY( p2.get() == a );
+  VERIFY( p.use_count() == 0 );
+  VERIFY( p2.use_count() == 1 );
+  p2.reset();
+  VERIFY( count == 0 );
+}
+
+int
+main()
+{
+  test01();
+  test02();
+  test03();
+  test04();
+  test05();
+  test06();
+  test07();
+  test08();
+  test09();
+  test10();
+  test11();
+  test12();
+  test13();
+  test14();
+  test15();
+}
diff --git a/libstdc++-v3/testsuite/20_util/shared_ptr/cons/unique_ptr_array.cc b/libstdc++-v3/testsuite/20_util/shared_ptr/cons/unique_ptr_array.cc
index 72eed47..bc1fcf1 100644
--- a/libstdc++-v3/testsuite/20_util/shared_ptr/cons/unique_ptr_array.cc
+++ b/libstdc++-v3/testsuite/20_util/shared_ptr/cons/unique_ptr_array.cc
@@ -22,6 +22,13 @@
 #include <memory>
 #include <testsuite_hooks.h>
 
+#if __cpp_lib_shared_ptr_arrays >= 201603
+# define SHARED_PTR_ARRAYS
+#endif
+#if __cpp_lib_enable_shared_from_this >= 201603
+# define WEAK_FROM_THIS
+#endif
+
 int destroyed = 0;
 
 struct A : std::enable_shared_from_this<A>
@@ -36,12 +43,22 @@ int
 test01()
 {
   std::unique_ptr<A[]> up(new A[2]);
+#ifdef SHARED_PTR_ARRAYS
+  std::shared_ptr<A[]> sp(std::move(up));
+#else
   std::shared_ptr<A> sp(std::move(up));
+#endif
   VERIFY( up.get() == 0 );
   VERIFY( sp.get() != 0 );
   VERIFY( sp.use_count() == 1 );
 
+#ifdef SHARED_PTR_ARRAYS
+# ifdef WEAK_FROM_THIS
+  VERIFY( sp[0].weak_from_this().expired() );
+# endif
+#else
   VERIFY( sp->shared_from_this() != nullptr );
+#endif
 
   sp.reset();
   VERIFY( destroyed == 2 );
diff --git a/libstdc++-v3/testsuite/20_util/shared_ptr/observers/array.cc b/libstdc++-v3/testsuite/20_util/shared_ptr/observers/array.cc
new file mode 100644
index 0000000..c47859d
--- /dev/null
+++ b/libstdc++-v3/testsuite/20_util/shared_ptr/observers/array.cc
@@ -0,0 +1,73 @@
+// { dg-do run { target c++11 } }
+
+// Copyright (C) 2016 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+#include <memory>
+#include <testsuite_hooks.h>
+
+struct A
+{
+  int i = 0;
+};
+
+// C++1z 20.11.2.2.5 shared_ptr observers [util.smartptr.shared.obs]
+
+// get
+void
+test01()
+{
+  A * const a = new A[2];
+  const std::shared_ptr<A[2]> p(a);
+  VERIFY( p.get() == a );
+}
+
+// get
+void
+test02()
+{
+  A * const a = new A[2];
+  const std::shared_ptr<A[]> p(a);
+  VERIFY( p.get() == a );
+}
+
+// operator[]
+void
+test03()
+{
+  A * const a = new A[2];
+  const std::shared_ptr<A[2]> p(a);
+  VERIFY( &p[0] == a );
+}
+
+// operator[]
+void
+test04()
+{
+  A * const a = new A[2];
+  const std::shared_ptr<A[]> p(a);
+  VERIFY( &p[0] == a );
+}
+
+int
+main()
+{
+  test01();
+  test02();
+  test03();
+  test04();
+}