Make std::scoped_allocator_adaptor's OUTERMOST recursive

Backport from mainline
2016-10-06  Jonathan Wakely  <jwakely@redhat.com>

	* doc/xml/manual/status_cxx2011.xml: Update status.
	* doc/html/manual/status.html: Regenerate.
	* include/std/scoped_allocator (__outer_allocator_t, __outermost_type):
	New helpers for recursive OUTERMOST.
	(__outermost): Use __outermost_type::_S_outermost.
	(__do_outermost, scoped_allocator_adaptor::__outermost_type): Remove.
	(scoped_allocator_adaptor::__outermost_alloc_traits): Use new
	__outermost_type helper.
	(scoped_allocator_adaptor::_Constructible): New alias template.
	(scoped_allocator_adaptor::scoped_allocator_adaptor<_Outer2>):
	Constrain template constructors.
	* testsuite/20_util/scoped_allocator/3.cc: New test.
	* testsuite/20_util/scoped_allocator/outermost.cc: New test.

From-SVN: r251590

6 files changed, 217 insertions, 24 deletions

diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index 8ab39d7..7f4feba 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,22 @@
+2017-09-01  Jonathan Wakely  <jwakely@redhat.com>
+
+	Backport from mainline
+	2016-10-06  Jonathan Wakely  <jwakely@redhat.com>
+
+	* doc/xml/manual/status_cxx2011.xml: Update status.
+	* doc/html/manual/status.html: Regenerate.
+	* include/std/scoped_allocator (__outer_allocator_t, __outermost_type):
+	New helpers for recursive OUTERMOST.
+	(__outermost): Use __outermost_type::_S_outermost.
+	(__do_outermost, scoped_allocator_adaptor::__outermost_type): Remove.
+	(scoped_allocator_adaptor::__outermost_alloc_traits): Use new
+	__outermost_type helper.
+	(scoped_allocator_adaptor::_Constructible): New alias template.
+	(scoped_allocator_adaptor::scoped_allocator_adaptor<_Outer2>):
+	Constrain template constructors.
+	* testsuite/20_util/scoped_allocator/3.cc: New test.
+	* testsuite/20_util/scoped_allocator/outermost.cc: New test.
+
 2017-06-16  Jonathan Wakely  <jwakely@redhat.com>
 
 	* include/bits/locale_conv.h (wbuffer_convert::sync): Fix condition.
diff --git a/libstdc++-v3/doc/html/manual/status.html b/libstdc++-v3/doc/html/manual/status.html
index f82a3c5..46eb193 100644
--- a/libstdc++-v3/doc/html/manual/status.html
+++ b/libstdc++-v3/doc/html/manual/status.html
@@ -172,7 +172,7 @@ This page describes the C++11 support in the GCC 5 series.
       </td></tr><tr><td align="left">20.1</td><td align="left">General</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.2</td><td align="left">Utility components</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.2.1</td><td align="left">Operators</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.2.2</td><td align="left">Swap</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.2.3</td><td align="left"><code class="code">forward</code> and <code class="code">move</code> helpers</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.2.4</td><td align="left">Function template <code class="code">declval</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.3</td><td align="left">Pairs</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.3.1</td><td align="left">In general</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.3.2</td><td align="left">Class template <code class="code">pair</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.3.3</td><td align="left">Specialized algorithms</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.3.4</td><td align="left">Tuple-like access to <code class="code">pair</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.3.5</td><td align="left">Piecewise construction</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.4</td><td align="left">Tuples</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.4.1</td><td align="left">In general</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.4.2</td><td align="left">Class template <code class="code">tuple</code></td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.4.2.1</td><td align="left">Construction</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.4.2.2</td><td align="left">Assignment</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.4.2.3</td><td align="left">Swap</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.4.2.4</td><td align="left">Tuple creation functions</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.4.2.5</td><td align="left">Tuple helper classes</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.4.2.6</td><td align="left">Element access</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.4.2.7</td><td align="left">Relational operators</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.4.2.8</td><td align="left">Tuple traits</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.4.2.9</td><td align="left">Tuple specialized algorithms</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.5</td><td align="left">Class template <code class="code">bitset</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.5.1</td><td align="left"><code class="code">bitset</code> constructors</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.5.2</td><td align="left"><code class="code">bitset</code> members</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.5.3</td><td align="left"><code class="code">bitset</code> hash support</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.5.4</td><td align="left"><code class="code">bitset</code> operators</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.6</td><td align="left">Memory</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.6.1</td><td align="left">In general</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.6.2</td><td align="left">Header <code class="code">&lt;memory&gt;</code> synopsis</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.6.3</td><td align="left">Pointer traits</td><td align="left">Y</td><td align="left"> </td></tr><tr bgcolor="#B0B0B0"><td align="left">20.6.4</td><td align="left">Pointer safety</td><td align="left">Partial</td><td align="left"> </td></tr><tr><td align="left">20.6.5</td><td align="left">Align</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.6.6</td><td align="left">Allocator argument tag</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.6.7</td><td align="left"><code class="code">uses_allocator</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.6.8</td><td align="left">Allocator traits</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.6.9</td><td align="left">The default allocator</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.6.10</td><td align="left">Raw storage iterator</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.6.11</td><td align="left">Temporary buffers</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.6.12</td><td align="left">Specialized algorithms</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.6.12.1</td><td align="left"><code class="code">addressof</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.6.12.2</td><td align="left"><code class="code">uninitialized_copy</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.6.12.3</td><td align="left"><code class="code">uninitialized_fill</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.6.12.4</td><td align="left"><code class="code">uninitialized_fill_n</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.6.13</td><td align="left">C library</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.7</td><td align="left">Smart pointers</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.7.1</td><td align="left">Class template <code class="code">unique_ptr</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.7.2</td><td align="left">Shared-ownership pointers</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.7.2.1</td><td align="left">Class <code class="code">bad_weak_ptr</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.7.2.2</td><td align="left">Class template <code class="code">shared_ptr</code></td><td align="left">Y</td><td align="left">
 	  Uses code from
 	  <a class="link" href="http://www.boost.org/libs/smart_ptr/shared_ptr.htm" target="_top">boost::shared_ptr</a>.
-      </td></tr><tr><td align="left">20.7.2.3</td><td align="left">Class template <code class="code">weak_ptr</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.7.2.4</td><td align="left">Class template <code class="code">emable_shared_from_this</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.7.2.5</td><td align="left"><code class="code">shared_ptr</code> atomic access</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.7.2.6</td><td align="left">Smart pointer hash support</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.8</td><td align="left">Function objects</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.8.1</td><td align="left">Definitions</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.8.2</td><td align="left">Requirements</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.8.3</td><td align="left">Class template <code class="code">reference_wrapper</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.8.4</td><td align="left">Arithmetic operation</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.8.5</td><td align="left">Comparisons</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.8.6</td><td align="left">Logical operations</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.8.7</td><td align="left">Bitwise operations</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.8.8</td><td align="left">Negators</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.8.9</td><td align="left">Function template <code class="code">bind</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.8.10</td><td align="left">Function template <code class="code">mem_fn</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.8.11</td><td align="left">Polymorphic function wrappers</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.8.11.1</td><td align="left">Class <code class="code">bad_function_call</code></td><td align="left">Y</td><td align="left"> </td></tr><tr bgcolor="#B0B0B0"><td align="left">20.8.11.2</td><td align="left">Class template <code class="code">function</code></td><td align="left">Partial</td><td align="left">Missing allocator support</td></tr><tr><td align="left">20.8.12</td><td align="left">Class template <code class="code">hash</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.9</td><td align="left">Metaprogramming and type traits</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.9.1</td><td align="left">Requirements</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.9.2</td><td align="left">Header <code class="code">&lt;type_traits&gt;</code> synopsis</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.9.3</td><td align="left">Helper classes</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.9.4</td><td align="left">Unary Type Traits</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.9.4.1</td><td align="left">Primary type categories</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.9.4.2</td><td align="left">Composite type traits</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.9.4.3</td><td align="left">Type properties</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.9.5</td><td align="left">Type property queries</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.9.6</td><td align="left">Relationships between types</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.9.7</td><td align="left">Transformations between types</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.9.7.1</td><td align="left">Const-volatile modifications</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.9.7.2</td><td align="left">Reference modifications</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.9.7.3</td><td align="left">Sign modifications</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.9.7.4</td><td align="left">Array modifications</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.9.7.5</td><td align="left">Pointer modifications</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.9.7.6</td><td align="left">Other transformations</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.10</td><td align="left">Compile-time rational arithmetic</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.10.1</td><td align="left">In general</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.10.2</td><td align="left">Header <code class="code">&lt;ratio&gt;</code> synopsis</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.10.3</td><td align="left">Class template <code class="code">ratio</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.10.4</td><td align="left">Arithmetic on <code class="code">ratio</code>s</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.10.5</td><td align="left">Comparison of <code class="code">ratio</code>s</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.10.6</td><td align="left">SI types for <code class="code">ratio</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.11</td><td align="left">Time utilities</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.11.3</td><td align="left">Clock requirements</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.11.4</td><td align="left">Time-related traits</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.11.4.1</td><td align="left"><code class="code">treat_as_floating_point</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.11.4.2</td><td align="left"><code class="code">duration_values</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.11.4.3</td><td align="left">Specializations of <code class="code">common_type</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.11.5</td><td align="left">Class template <code class="code">duration</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.11.6</td><td align="left">Class template <code class="code">time_point</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.11.7</td><td align="left">Clocks</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.11.7.1</td><td align="left">Class <code class="code">system_clock</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.11.7.2</td><td align="left">Class <code class="code">steady_clock</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.11.7.3</td><td align="left">Class <code class="code">high_resolution_clock</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.11.8</td><td align="left">Date and time functions</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.12</td><td align="left">Scoped allocator adaptor</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.12.1</td><td align="left">Header <code class="code">&lt;scoped_allocator&gt;</code> synopsis</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.12.2</td><td align="left">Scoped allocator adaptor member types</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.12.3</td><td align="left">Scoped allocator adaptor constructors</td><td align="left">Y</td><td align="left"> </td></tr><tr bgcolor="#B0B0B0"><td align="left">20.12.4</td><td align="left">Scoped allocator adaptor members</td><td align="left">Partial</td><td align="left">OUTERMOST is not recursive.</td></tr><tr><td align="left">20.12.5</td><td align="left">Scoped allocator operators</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.13</td><td align="left">Class <code class="code">type_index</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">
+      </td></tr><tr><td align="left">20.7.2.3</td><td align="left">Class template <code class="code">weak_ptr</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.7.2.4</td><td align="left">Class template <code class="code">emable_shared_from_this</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.7.2.5</td><td align="left"><code class="code">shared_ptr</code> atomic access</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.7.2.6</td><td align="left">Smart pointer hash support</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.8</td><td align="left">Function objects</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.8.1</td><td align="left">Definitions</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.8.2</td><td align="left">Requirements</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.8.3</td><td align="left">Class template <code class="code">reference_wrapper</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.8.4</td><td align="left">Arithmetic operation</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.8.5</td><td align="left">Comparisons</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.8.6</td><td align="left">Logical operations</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.8.7</td><td align="left">Bitwise operations</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.8.8</td><td align="left">Negators</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.8.9</td><td align="left">Function template <code class="code">bind</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.8.10</td><td align="left">Function template <code class="code">mem_fn</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.8.11</td><td align="left">Polymorphic function wrappers</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.8.11.1</td><td align="left">Class <code class="code">bad_function_call</code></td><td align="left">Y</td><td align="left"> </td></tr><tr bgcolor="#B0B0B0"><td align="left">20.8.11.2</td><td align="left">Class template <code class="code">function</code></td><td align="left">Partial</td><td align="left">Missing allocator support</td></tr><tr><td align="left">20.8.12</td><td align="left">Class template <code class="code">hash</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.9</td><td align="left">Metaprogramming and type traits</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.9.1</td><td align="left">Requirements</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.9.2</td><td align="left">Header <code class="code">&lt;type_traits&gt;</code> synopsis</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.9.3</td><td align="left">Helper classes</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.9.4</td><td align="left">Unary Type Traits</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.9.4.1</td><td align="left">Primary type categories</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.9.4.2</td><td align="left">Composite type traits</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.9.4.3</td><td align="left">Type properties</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.9.5</td><td align="left">Type property queries</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.9.6</td><td align="left">Relationships between types</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.9.7</td><td align="left">Transformations between types</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.9.7.1</td><td align="left">Const-volatile modifications</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.9.7.2</td><td align="left">Reference modifications</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.9.7.3</td><td align="left">Sign modifications</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.9.7.4</td><td align="left">Array modifications</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.9.7.5</td><td align="left">Pointer modifications</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.9.7.6</td><td align="left">Other transformations</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.10</td><td align="left">Compile-time rational arithmetic</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.10.1</td><td align="left">In general</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.10.2</td><td align="left">Header <code class="code">&lt;ratio&gt;</code> synopsis</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.10.3</td><td align="left">Class template <code class="code">ratio</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.10.4</td><td align="left">Arithmetic on <code class="code">ratio</code>s</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.10.5</td><td align="left">Comparison of <code class="code">ratio</code>s</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.10.6</td><td align="left">SI types for <code class="code">ratio</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.11</td><td align="left">Time utilities</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.11.3</td><td align="left">Clock requirements</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.11.4</td><td align="left">Time-related traits</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.11.4.1</td><td align="left"><code class="code">treat_as_floating_point</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.11.4.2</td><td align="left"><code class="code">duration_values</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.11.4.3</td><td align="left">Specializations of <code class="code">common_type</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.11.5</td><td align="left">Class template <code class="code">duration</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.11.6</td><td align="left">Class template <code class="code">time_point</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.11.7</td><td align="left">Clocks</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.11.7.1</td><td align="left">Class <code class="code">system_clock</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.11.7.2</td><td align="left">Class <code class="code">steady_clock</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.11.7.3</td><td align="left">Class <code class="code">high_resolution_clock</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.11.8</td><td align="left">Date and time functions</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.12</td><td align="left">Scoped allocator adaptor</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.12.1</td><td align="left">Header <code class="code">&lt;scoped_allocator&gt;</code> synopsis</td><td align="left"> </td><td align="left"> </td></tr><tr><td align="left">20.12.2</td><td align="left">Scoped allocator adaptor member types</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.12.3</td><td align="left">Scoped allocator adaptor constructors</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.12.4</td><td align="left">Scoped allocator adaptor members</td><td align="left">Y</td><td align="left"></td></tr><tr><td align="left">20.12.5</td><td align="left">Scoped allocator operators</td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">20.13</td><td align="left">Class <code class="code">type_index</code></td><td align="left">Y</td><td align="left"> </td></tr><tr><td align="left">
 	<span class="emphasis"><em>21</em></span>
       </td><td colspan="3" align="left">
 	<span class="emphasis"><em>Strings</em></span>
diff --git a/libstdc++-v3/doc/xml/manual/status_cxx2011.xml b/libstdc++-v3/doc/xml/manual/status_cxx2011.xml
index 7769f52..5188ab3 100644
--- a/libstdc++-v3/doc/xml/manual/status_cxx2011.xml
+++ b/libstdc++-v3/doc/xml/manual/status_cxx2011.xml
@@ -1007,11 +1007,10 @@ This page describes the C++11 support in the GCC 5 series.
       <entry/>
     </row>
     <row>
-      <?dbhtml bgcolor="#B0B0B0" ?>
       <entry>20.12.4</entry>
       <entry>Scoped allocator adaptor members</entry>
-      <entry>Partial</entry>
-      <entry>OUTERMOST is not recursive.</entry>
+      <entry>Y</entry>
+      <entry/>
     </row>
     <row>
       <entry>20.12.5</entry>
diff --git a/libstdc++-v3/include/std/scoped_allocator b/libstdc++-v3/include/std/scoped_allocator
index d163edd..5beb3a9 100644
--- a/libstdc++-v3/include/std/scoped_allocator
+++ b/libstdc++-v3/include/std/scoped_allocator
@@ -74,22 +74,36 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     : allocator_traits<_Alloc>::propagate_on_container_swap
     { };
 
-
   template<typename _Alloc>
-    inline auto
-    __do_outermost(_Alloc& __a, _Alloc*) -> decltype(__a.outer_allocator())
-    { return __a.outer_allocator(); }
+    using __outer_allocator_t
+      = decltype(std::declval<_Alloc>().outer_allocator());
+
+  template<typename _Alloc, typename = void>
+    struct __outermost_type
+    {
+      using type = _Alloc;
+      static type& _S_outermost(_Alloc& __a) { return __a; }
+    };
 
   template<typename _Alloc>
-    inline _Alloc&
-    __do_outermost(_Alloc& __a, ...)
-    { return __a; }
+    struct __outermost_type<_Alloc, __void_t<__outer_allocator_t<_Alloc>>>
+    : __outermost_type<
+      typename remove_reference<__outer_allocator_t<_Alloc>>::type
+    >
+    {
+      using __base = __outermost_type<
+        typename remove_reference<__outer_allocator_t<_Alloc>>::type
+      >;
+
+      static typename __base::type&
+      _S_outermost(_Alloc& __a)
+      { return __base::_S_outermost(__a.outer_allocator()); }
+    };
 
-  // TODO: make recursive (see note in 20.12.4/1)
   template<typename _Alloc>
-    inline auto
-    __outermost(_Alloc& __a) -> decltype(__do_outermost(__a, &__a))
-    { return __do_outermost(__a, &__a); }
+    inline typename __outermost_type<_Alloc>::type&
+    __outermost(_Alloc& __a)
+    { return __outermost_type<_Alloc>::_S_outermost(__a); }
 
   template<typename _OuterAlloc, typename... _InnerAllocs>
     class scoped_allocator_adaptor;
@@ -196,13 +210,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       { return std::tuple_cat(std::tie(outer_allocator()), _M_inner._M_tie()); }
 
       template<typename _Alloc>
-	using __outermost_type = typename
-	  std::decay<decltype(__outermost(std::declval<_Alloc&>()))>::type;
-
-      template<typename _Alloc>
 	using __outermost_alloc_traits
-	  = allocator_traits<__outermost_type<_Alloc>>;
-      
+	  = allocator_traits<typename __outermost_type<_Alloc>::type>;
+
       template<typename _Tp, typename... _Args>
         void 
         _M_construct(__uses_alloc0, _Tp* __p, _Args&&... __args)
@@ -251,6 +261,12 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
           _M_inner(_S_select_on_copy(std::get<_Indices+1>(__refs))...)
         { }
 
+      // Used to constrain constructors to disallow invalid conversions.
+      template<typename _Alloc>
+        using _Constructible = typename enable_if<
+            is_constructible<_OuterAlloc, _Alloc>::value
+          >::type;
+
     public:
       typedef _OuterAlloc                       outer_allocator_type;
       typedef typename __inner_type::__type     inner_allocator_type;
@@ -283,7 +299,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
       scoped_allocator_adaptor() : _OuterAlloc(), _M_inner() { }
 
-      template<typename _Outer2>
+      template<typename _Outer2, typename = _Constructible<_Outer2>>
         scoped_allocator_adaptor(_Outer2&& __outer,
                                  const _InnerAllocs&... __inner)
         : _OuterAlloc(std::forward<_Outer2>(__outer)),
@@ -300,14 +316,14 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 	_M_inner(std::move(__other._M_inner))
       { }
 
-      template<typename _Outer2>
+      template<typename _Outer2, typename = _Constructible<const _Outer2&>>
         scoped_allocator_adaptor(
             const scoped_allocator_adaptor<_Outer2, _InnerAllocs...>& __other)
         : _OuterAlloc(__other.outer_allocator()),
           _M_inner(__other._M_inner)
         { }
 
-      template<typename _Outer2>
+      template<typename _Outer2, typename = _Constructible<_Outer2>>
         scoped_allocator_adaptor(
             scoped_allocator_adaptor<_Outer2, _InnerAllocs...>&& __other)
         : _OuterAlloc(std::move(__other.outer_allocator())),
diff --git a/libstdc++-v3/testsuite/20_util/scoped_allocator/3.cc b/libstdc++-v3/testsuite/20_util/scoped_allocator/3.cc
new file mode 100644
index 0000000..c96c9aa
--- /dev/null
+++ b/libstdc++-v3/testsuite/20_util/scoped_allocator/3.cc
@@ -0,0 +1,67 @@
+// 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/>.
+
+// { dg-do compile }
+// { dg-options "-std=gnu++11" }
+
+#include <scoped_allocator>
+#include <testsuite_allocator.h>
+
+template<typename T>
+struct alloc
+{
+  using value_type = T;
+  alloc() = default;
+  template<typename U>
+    alloc(alloc<U>) { }
+  T* allocate(std::size_t);
+  void deallocate(T*, std::size_t);
+};
+
+template<typename T, typename U>
+  bool operator==(alloc<T>, alloc<U>) { return true; }
+
+template<typename T, typename U>
+  bool operator!=(alloc<T>, alloc<U>) { return false; }
+
+using scoped = std::scoped_allocator_adaptor<alloc<int>>;
+using other_alloc = __gnu_test::SimpleAllocator<int>;
+using other_scoped = std::scoped_allocator_adaptor<other_alloc>;
+
+using std::is_constructible;
+
+static_assert( is_constructible<scoped, const scoped&>::value,
+    "is_constructible<scoped, const scoped&>");
+static_assert( is_constructible<scoped, scoped>::value,
+    "is_constructible<scoped, scoped>");
+static_assert( is_constructible<scoped, const alloc<int>&>::value,
+    "is_constructible<scoped, const outer_allocator_type&>");
+static_assert( is_constructible<scoped, alloc<int>>::value,
+    "is_constructible<scoped, outer_allocator_type>");
+static_assert( is_constructible<scoped, const alloc<long>&>::value,
+    "is_constructible<scoped, const outer_allocator_type::rebind<U>::type&>");
+static_assert( is_constructible<scoped, alloc<long>>::value,
+    "is_constructible<scoped, outer_allocator_type::rebind<U>::type>");
+
+static_assert( !is_constructible<scoped, const other_alloc&>::value,
+    "!is_constructible<scoped, const other_alloc&>");
+static_assert( !is_constructible<scoped, other_alloc>::value,
+    "!is_constructible<scoped, other_alloc>");
+static_assert( !is_constructible<scoped, const other_scoped&>::value,
+    "!is_constructible<scoped, const other_scoped&>");
+static_assert( !is_constructible<scoped, other_scoped>::value,
+    "!is_constructible<scoped, other_scoped>");
diff --git a/libstdc++-v3/testsuite/20_util/scoped_allocator/outermost.cc b/libstdc++-v3/testsuite/20_util/scoped_allocator/outermost.cc
new file mode 100644
index 0000000..5973adc
--- /dev/null
+++ b/libstdc++-v3/testsuite/20_util/scoped_allocator/outermost.cc
@@ -0,0 +1,92 @@
+// 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/>.
+
+// { dg-do compile }
+// { dg-options "-std=gnu++11" }
+
+#include <scoped_allocator>
+
+template<typename T>
+struct alloc
+{
+  using value_type = T;
+  alloc() = default;
+  template<typename U>
+    alloc(alloc<U>) { }
+  T* allocate(std::size_t);
+  void deallocate(T*, std::size_t);
+};
+
+template<typename T, typename U>
+  bool operator==(alloc<T>, alloc<U>) { return true; }
+
+template<typename T, typename U>
+  bool operator!=(alloc<T>, alloc<U>) { return false; }
+
+struct X
+{
+  using allocator_type = alloc<int>;
+  X(const allocator_type&);
+};
+
+template<typename A>
+struct nested_alloc : A
+{
+  nested_alloc() = default;
+  template<typename U>
+    nested_alloc(nested_alloc<U>) { }
+
+  A& outer_allocator() { return *this; }
+
+  template<typename U, typename... Args>
+    void construct(U*, Args&&...)
+    {
+      static_assert(!std::is_same<U, X>::value,
+          "OUTERMOST should recurse and use alloc<int> to construct X");
+    }
+};
+
+template<typename T, typename U>
+  bool operator==(nested_alloc<T> l, nested_alloc<U> r)
+  { return l.outer_allocator() == r.outer_allocator(); }
+
+template<typename T, typename U>
+  bool operator!=(nested_alloc<T> l, nested_alloc<U> r)
+  { return !(l == r); }
+
+template<typename A>
+  using scoped_alloc = std::scoped_allocator_adaptor<A>;
+
+void
+test01()
+{
+  scoped_alloc<nested_alloc<alloc<int>>> a;
+  alignas(X) char buf[sizeof(X)];
+  X* p = (X*)buf;
+  // Test that OUTERMOST is recursive and doesn't just unwrap one level:
+  a.construct(p);
+}
+
+void
+test02()
+{
+  scoped_alloc<scoped_alloc<nested_alloc<alloc<int>>>> a;
+  alignas(X) char buf[sizeof(X)];
+  X* p = (X*)buf;
+  // Test that OUTERMOST is recursive and doesn't just unwrap one level:
+  a.construct(p);
+}