| //===----------------------------------------------------------------------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is dual licensed under the MIT and the University of Illinois Open |
| // Source Licenses. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| // <optional> |
| // UNSUPPORTED: c++98, c++03, c++11, c++14 |
| // UNSUPPORTED: clang-5 |
| // UNSUPPORTED: libcpp-no-deduction-guides |
| // Clang 5 will generate bad implicit deduction guides |
| // Specifically, for the copy constructor. |
| |
| |
| // template<class T> |
| // optional(T) -> optional<T>; |
| |
| |
| #include <optional> |
| #include <cassert> |
| |
| struct A {}; |
| |
| int main() |
| { |
| // Test the explicit deduction guides |
| |
| // Test the implicit deduction guides |
| { |
| // optional() |
| 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. |
| } |
| |
| { |
| // optional(nullopt_t) |
| std::optional opt(std::nullopt); // expected-error-re@optional:* {{static_assert failed{{.*}} "instantiation of optional with nullopt_t is ill-formed"}} |
| } |
| } |
