42 lines
1.1 KiB
C++
42 lines
1.1 KiB
C++
//===----------------------------------------------------------------------===//
|
|
//
|
|
// 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>
|
|
|
|
// template <class T> constexpr bool operator!=(const optional<T>& x, nullopt_t) noexcept;
|
|
// template <class T> constexpr bool operator!=(nullopt_t, const optional<T>& x) noexcept;
|
|
|
|
#include <experimental/optional>
|
|
|
|
int main()
|
|
{
|
|
#if _LIBCPP_STD_VER > 11
|
|
using std::experimental::optional;
|
|
using std::experimental::nullopt_t;
|
|
using std::experimental::nullopt;
|
|
|
|
{
|
|
typedef int T;
|
|
typedef optional<T> O;
|
|
|
|
constexpr O o1; // disengaged
|
|
constexpr O o2{1}; // engaged
|
|
|
|
static_assert ( !(nullopt != o1), "" );
|
|
static_assert ( (nullopt != o2), "" );
|
|
static_assert ( !(o1 != nullopt), "" );
|
|
static_assert ( (o2 != nullopt), "" );
|
|
|
|
static_assert (noexcept(nullopt != o1), "");
|
|
static_assert (noexcept(o1 != nullopt), "");
|
|
}
|
|
#endif
|
|
}
|