Implement P0739R0: 'Some improvements to class template argument deduction integration into the standard library' This is an API change (not ABI change) due to a late change in the c++17 standard

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@309296 91177308-0d34-0410-b5e6-96231b3b80d8

include/mutex

@@ -116,7 +116,7 @@ public:
     using mutex_type = Mutex;  // If MutexTypes... consists of the single type Mutex
 
     explicit scoped_lock(MutexTypes&... m);
-    scoped_lock(MutexTypes&... m, adopt_lock_t);
+    scoped_lock(adopt_lock_t, MutexTypes&... m);
     ~scoped_lock();
     scoped_lock(scoped_lock const&) = delete;
     scoped_lock& operator=(scoped_lock const&) = delete;
@@ -500,7 +500,7 @@ public:
     ~scoped_lock() _LIBCPP_THREAD_SAFETY_ANNOTATION(release_capability()) {__m_.unlock();}
 
     _LIBCPP_INLINE_VISIBILITY
-    explicit scoped_lock(mutex_type& __m, adopt_lock_t) _LIBCPP_THREAD_SAFETY_ANNOTATION(requires_capability(__m))
+    explicit scoped_lock(adopt_lock_t, mutex_type& __m) _LIBCPP_THREAD_SAFETY_ANNOTATION(requires_capability(__m))
         : __m_(__m) {}
 
     scoped_lock(scoped_lock const&) = delete;
@@ -522,7 +522,7 @@ public:
     }
 
     _LIBCPP_INLINE_VISIBILITY
-    scoped_lock(_MArgs&... __margs, adopt_lock_t)
+    scoped_lock(adopt_lock_t, _MArgs&... __margs)
         : __t_(__margs...)
     {
     }

test/std/thread/thread.mutex/thread.lock/thread.lock.scoped/adopt_lock.pass.cpp

@@ -14,7 +14,7 @@
 
 // template <class ...Mutex> class scoped_lock;
 
-// scoped_lock(Mutex&..., adopt_lock_t);
+// scoped_lock(adopt_lock_t, Mutex&...);
 
 #include <mutex>
 #include <cassert>
@@ -43,7 +43,7 @@ int main()
         using LG = std::scoped_lock<TestMutex>;
         m1.lock();
         {
-            LG lg(m1, std::adopt_lock);
+            LG lg(std::adopt_lock, m1);
             assert(m1.locked);
         }
         assert(!m1.locked);
@@ -53,7 +53,7 @@ int main()
         using LG = std::scoped_lock<TestMutex, TestMutex>;
         m1.lock(); m2.lock();
         {
-            LG lg(m1, m2, std::adopt_lock);
+            LG lg(std::adopt_lock, m1, m2);
             assert(m1.locked && m2.locked);
         }
         assert(!m1.locked && !m2.locked);
@@ -63,7 +63,7 @@ int main()
         using LG = std::scoped_lock<TestMutex, TestMutex, TestMutex>;
         m1.lock(); m2.lock(); m3.lock();
         {
-            LG lg(m1, m2, m3, std::adopt_lock);
+            LG lg(std::adopt_lock, m1, m2, m3);
             assert(m1.locked && m2.locked && m3.locked);
         }
         assert(!m1.locked && !m2.locked && !m3.locked);

test/std/utilities/variant/variant.variant/variant.ctor/copy.pass.cpp

@@ -261,4 +261,9 @@ int main() {
   test_copy_ctor_valueless_by_exception();
   test_copy_ctor_sfinae();
   test_constexpr_copy_ctor_extension();
+{ // This is the motivating example from P0739R0
+  std::variant<int, double> v1(3);
+  std::variant v2 = v1;
+  (void) v2;
+}
 }

www/cxx1z_status.html

@@ -39,6 +39,8 @@
   <p>In February 2017, the C++ standard committee approved this draft, and sent it to ISO for approval as C++17</p>
   <p>This page shows the status of libc++; the status of clang's support of the language features is <a href="http://clang.llvm.org/cxx_status.html#cxx17">here</a>.</p>
 
+  <p>Reminder: Features in unreleased drafts of the standard are subject to change.</p>
+
   <p>The groups that have contributed papers:
   <ul>
     <li>LWG - Library working group</li>
@@ -163,7 +165,7 @@
 	<tr><td><a href="http://wg21.link/P0623R0">P0623R0</a></td><td>LWG</td><td>Final C++17 Parallel Algorithms Fixes</td><td>Kona</td><td></td><td></td></tr>
   	<tr><td></td><td></td><td></td><td></td><td></td><td></td></tr>
 	<tr><td><a href="http://wg21.link/P0682R1">P0682R1</a></td><td>LWG</td><td>Repairing elementary string conversions</td><td>Toronto</td><td></td><td></td></tr>
-	<tr><td><a href="http://wg21.link/P0739R0">P0739R0</a></td><td>LWG</td><td>Some improvements to class template argument deduction integration into the standard library</td><td>Toronto</td><td></td><td></td></tr>
+	<tr><td><a href="http://wg21.link/P0739R0">P0739R0</a></td><td>LWG</td><td>Some improvements to class template argument deduction integration into the standard library</td><td>Toronto</td><td>Complete</td><td>5.0</td></tr>
 
 <!--  	<tr><td></td><td></td><td></td><td></td><td></td><td></td></tr> -->
   </table>
@@ -497,7 +499,7 @@
 <!-- 	<tr><td></td><td></td><td></td><td></td></tr> -->
   </table>
 
-  <p>Last Updated: 25-May-2017</p>
+  <p>Last Updated: 27-Jul-2017</p>
 </div>
 </body>
 </html>

www/cxx2a_status.html

@@ -38,6 +38,8 @@
   <p>In July 2017, the C++ standard committee created a draft for the next version of the C++ standard, known here as "C++2a" (probably to be C++20).</p>
   <p>This page shows the status of libc++; the status of clang's support of the language features is <a href="http://clang.llvm.org/cxx_status.html#cxx2a">here</a>.</p>
 
+  <p>Reminder: Features in unreleased drafts of the standard are subject to change.</p>
+
   <p>The groups that have contributed papers:
   <ul>
     <li>LWG - Library working group</li>