//===----------------------------------------------------------------------===//
//
//                     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, const T& v);
// template <class T> constexpr bool operator==(const T& v, const optional<T>& x);

#include <optional>

int main()
{
#if _LIBCPP_STD_VER > 11
    {
    typedef int T;
    typedef std::optional<T> O;
    
    constexpr T val(2);
    constexpr O o1;     // disengaged
    constexpr O o2{1};  // engaged
    constexpr O o3{val};  // engaged

    static_assert ( !(o1 == 1), "" );
    static_assert (   o2 == 1,  "" );
    static_assert ( !(o3 == 1), "" );
    static_assert (   o3 == 2 , "" );
    static_assert (   o3 == val, "" );
        
    static_assert ( !(1 == o1), "" );
    static_assert (   1 == o2,  "" );
    static_assert ( !(1 == o3), "" );
    static_assert (   2 == o3 , "" );
    static_assert ( val == o3 , "" );
    }
#endif
}