| //===----------------------------------------------------------------------===// |
| // |
| // 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. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| // UNSUPPORTED: c++98, c++03, c++11, c++14 |
| // <optional> |
| |
| // template <class T, class U> constexpr bool operator==(const optional<T>& x, const U& v); |
| // template <class T, class U> constexpr bool operator==(const U& v, const optional<T>& x); |
| |
| #include <optional> |
| |
| using std::optional; |
| |
| struct X { |
| int i_; |
| |
| constexpr X(int i) : i_(i) {} |
| }; |
| |
| constexpr bool operator==(const X& lhs, const X& rhs) { |
| return lhs.i_ == rhs.i_; |
| } |
| |
| int main() { |
| { |
| typedef X T; |
| typedef optional<T> O; |
| |
| constexpr T val(2); |
| constexpr O o1; // disengaged |
| constexpr O o2{1}; // engaged |
| constexpr O o3{val}; // engaged |
| |
| static_assert(!(o1 == T(1)), ""); |
| static_assert((o2 == T(1)), ""); |
| static_assert(!(o3 == T(1)), ""); |
| static_assert((o3 == T(2)), ""); |
| static_assert((o3 == val), ""); |
| |
| static_assert(!(T(1) == o1), ""); |
| static_assert((T(1) == o2), ""); |
| static_assert(!(T(1) == o3), ""); |
| static_assert((T(2) == o3), ""); |
| static_assert((val == o3), ""); |
| } |
| { |
| using O = optional<int>; |
| constexpr O o1(42); |
| static_assert(o1 == 42l, ""); |
| static_assert(!(101l == o1), ""); |
| } |
| { |
| using O = optional<const int>; |
| constexpr O o1(42); |
| static_assert(o1 == 42, ""); |
| static_assert(!(101 == o1), ""); |
| } |
| } |