114                                convertible_to<char16&> rto_c16,  in test_implicit_conversions()  argument
140   (void)(rto_c16 = to_c16); // expected-error{{no viable overloaded '='}}  in test_implicit_conversions()
141   (void)(rto_c16 += to_c16);  in test_implicit_conversions()
142   (void)(rto_c16 -= to_c16);  in test_implicit_conversions()
143   (void)(rto_c16 *= to_c16);  in test_implicit_conversions()
144   (void)(rto_c16 /= to_c16);  in test_implicit_conversions()
178   (void)(rto_c16 = c16e); // expected-error{{no viable overloaded '='}}  in test_implicit_conversions()
179   (void)(rto_c16 += to_c16e);  in test_implicit_conversions()
180   (void)(rto_c16 -= to_c16e);  in test_implicit_conversions()
181   (void)(rto_c16 *= to_c16e);  in test_implicit_conversions()
182   (void)(rto_c16 /= to_c16e);  in test_implicit_conversions()