0166690401
All supported compilers have supported deduction guides in C++17 for a while, so this isn't necessary anymore. Differential Revision: https://reviews.llvm.org/D108213
55 lines
1.4 KiB
C++
55 lines
1.4 KiB
C++
//===----------------------------------------------------------------------===//
|
|
//
|
|
// 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
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
// <optional>
|
|
// UNSUPPORTED: c++03, c++11, c++14
|
|
// UNSUPPORTED: clang-5, apple-clang-9
|
|
// Clang 5 will generate bad implicit deduction guides
|
|
// Specifically, for the copy constructor.
|
|
|
|
// template<class T>
|
|
// optional(T) -> optional<T>;
|
|
|
|
#include <optional>
|
|
#include <cassert>
|
|
|
|
#include "test_macros.h"
|
|
|
|
struct A {};
|
|
|
|
int main(int, char**)
|
|
{
|
|
// Test the explicit deduction guides
|
|
{
|
|
// optional(T)
|
|
std::optional opt(5);
|
|
static_assert(std::is_same_v<decltype(opt), std::optional<int>>, "");
|
|
assert(static_cast<bool>(opt));
|
|
assert(*opt == 5);
|
|
}
|
|
|
|
{
|
|
// optional(T)
|
|
std::optional opt(A{});
|
|
static_assert(std::is_same_v<decltype(opt), std::optional<A>>, "");
|
|
assert(static_cast<bool>(opt));
|
|
}
|
|
|
|
// Test the implicit deduction guides
|
|
{
|
|
// optional(optional);
|
|
std::optional<char> source('A');
|
|
std::optional opt(source);
|
|
static_assert(std::is_same_v<decltype(opt), std::optional<char>>, "");
|
|
assert(static_cast<bool>(opt) == static_cast<bool>(source));
|
|
assert(*opt == *source);
|
|
}
|
|
|
|
return 0;
|
|
}
|