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//===----------------------------------------------------------------------===//
//
// 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 <experimental/optional>
#if _LIBCPP_STD_VER > 11
using std::experimental::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_ ; }
#endif
int main()
{
#if _LIBCPP_STD_VER > 11
{
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 ( o2 < T(2) , "" );
static_assert ( o2 < T(val), "" );
static_assert ( o3 < T(3) , "" );
static_assert ( !(T(1) < o1), "" );
static_assert ( !(T(1) < o2), "" );
static_assert ( T(1) < o3 , "" );
static_assert ( !(T(2) < o2), "" );
static_assert (!(T(val) < o2), "" );
static_assert ( !(T(3) < o3), "" );
}
#endif
}
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