Specify clear as noexcept

test/unordered/compile_tests.hpp

@@ -554,6 +554,7 @@ void unordered_test(X& x, Key& k, Hash& hf, Pred& eq)
     const_iterator q1 = a.cbegin(), q2 = a.cend();
     test::check_return_type<iterator>::equals(a.erase(q1, q2));
 
+    TEST_NOEXCEPT_EXPR(a.clear());
     a.clear();
 
     X const b;