Add std::vector::emplace() testcase from LWG 2164

	* testsuite/23_containers/vector/modifiers/emplace/self_emplace.cc:
	Add testcase from LWG 2164.

From-SVN: r238243

libstdc++-v3/ChangeLog

+2016-07-12  Jonathan Wakely  <jwakely@redhat.com>
+
+	* testsuite/23_containers/vector/modifiers/emplace/self_emplace.cc:
+	Add testcase from LWG 2164.
+
 2016-07-11  François Dumont  <fdumont@gcc.gnu.org>
 
 	* include/bits/stl_vector.h (push_back(const value_type&)): Forward

libstdc++-v3/testsuite/23_containers/vector/modifiers/emplace/self_emplace.cc

@@ -135,6 +135,20 @@ test04()
   VERIFY( va[0]._i == 1 );
 }
 
+void
+test05()
+{
+  // LWG DR 2164
+  std::vector<int> v;
+  v.reserve(4);
+  v = { 1, 2, 3 };
+  v.emplace(v.begin(), v.back());
+  VERIFY( v[0] == 3 );
+  VERIFY( v[1] == 1 );
+  VERIFY( v[2] == 2 );
+  VERIFY( v[3] == 3 );
+}
+
 int main()
 {
   test01();