Add tests specifically for LWG2164. We already did this; but now we have tests. NFC

llvm-svn: 359458

libcxx/test/std/containers/sequences/vector/vector.modifiers/emplace_back.pass.cpp

@@ -145,5 +145,16 @@ int main(int, char**)
         assert(is_contiguous_container_asan_correct(c));
     }
 
+    { // LWG 2164
+        int arr[] = {0, 1, 2, 3, 4};
+        int sz = 5;
+        std::vector<int> c(arr, arr+sz);
+        while (c.size() < c.capacity())
+            c.push_back(sz++);
+        c.emplace_back(c.front());
+        assert(c.back() == 0);
+        for (int i = 0; i < sz; ++i)
+            assert(c[i] == i);
+    }
   return 0;
 }

libcxx/test/std/containers/sequences/vector/vector.modifiers/pop_back.pass.cpp

@@ -38,5 +38,17 @@ int main(int, char**)
     }
 #endif
 
+    { // LWG 526
+        int arr[] = {0, 1, 2, 3, 4};
+        int sz = 5;
+        std::vector<int> c(arr, arr+sz);
+        while (c.size() < c.capacity())
+            c.push_back(sz++);
+        c.push_back(c.front());
+        assert(c.back() == 0);
+        for (int i = 0; i < sz; ++i)
+            assert(c[i] == i);
+    }
+
   return 0;
 }

libcxx/www/cxx2a_status.html

@@ -216,7 +216,7 @@
 	<tr><td><a href="https://wg21.link/LWG3024">3024</a></td><td>variant's copies must be deleted instead of disabled via SFINAE</td><td>Albuquerque</td><td></td></tr>
 
  	<tr><td></td><td></td><td></td><td></td></tr>
-	<tr><td><a href="https://wg21.link/LWG2164">2164</a></td><td>What are the semantics of <tt>vector.emplace(vector.begin(), vector.back())</tt>?</td><td>Jacksonville</td><td></td></tr>
+	<tr><td><a href="https://wg21.link/LWG2164">2164</a></td><td>What are the semantics of <tt>vector.emplace(vector.begin(), vector.back())</tt>?</td><td>Jacksonville</td><td>Complete</td></tr>
 	<tr><td><a href="https://wg21.link/LWG2243">2243</a></td><td><tt>istream::putback</tt> problem</td><td>Jacksonville</td><td>Complete</td></tr>
 	<tr><td><a href="https://wg21.link/LWG2816">2816</a></td><td><tt>resize_file</tt> has impossible postcondition</td><td>Jacksonville</td><td><i>Nothing to do</i></td></tr>
 	<tr><td><a href="https://wg21.link/LWG2843">2843</a></td><td>Unclear behavior of <tt>std::pmr::memory_resource::do_allocate()</tt></td><td>Jacksonville</td><td>Complete</td></tr>