| //===----------------------------------------------------------------------===// |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| //===----------------------------------------------------------------------===// |
| // UNSUPPORTED: c++98, c++03, c++11, c++14 |
| // UNSUPPORTED: libcpp-no-deduction-guides |
| // Clang 5 will generate bad implicit deduction guides |
| // Specifically, for the copy constructor. |
| // optional(T) -> optional<T>; |
| // Test the explicit deduction guides |
| // Test the implicit deduction guides |
| std::optional opt; // expected-error-re {{{{declaration of variable 'opt' with deduced type 'std::optional' requires an initializer|no viable constructor or deduction guide for deduction of template arguments of 'optional'}}}} |
| // clang-6 gives a bogus error here: |
| // declaration of variable 'opt' with deduced type 'std::optional' requires an initializer |
| // clang-7 (and later) give a better message: |
| // no viable constructor or deduction guide for deduction of template arguments of 'optional' |
| // So we check for one or the other. |
| std::optional opt(std::nullopt); // expected-error-re@optional:* {{static_assert failed{{.*}} "instantiation of optional with nullopt_t is ill-formed"}} |