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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 optional<T>& y);
#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 optional<X> O;
constexpr O o1; // disengaged
constexpr O o2; // disengaged
constexpr O o3{1}; // engaged
constexpr O o4{2}; // engaged
constexpr O o5{1}; // engaged
static_assert ( !(o1 < o1), "" );
static_assert ( !(o1 < o2), "" );
static_assert ( o1 < o3 , "" );
static_assert ( o1 < o4 , "" );
static_assert ( o1 < o5 , "" );
static_assert ( !(o2 < o1), "" );
static_assert ( !(o2 < o2), "" );
static_assert ( o2 < o3 , "" );
static_assert ( o2 < o4 , "" );
static_assert ( o2 < o5 , "" );
static_assert ( !(o3 < o1), "" );
static_assert ( !(o3 < o2), "" );
static_assert ( !(o3 < o3), "" );
static_assert ( o3 < o4 , "" );
static_assert ( !(o3 < o5), "" );
static_assert ( !(o4 < o1), "" );
static_assert ( !(o4 < o2), "" );
static_assert ( !(o4 < o3), "" );
static_assert ( !(o4 < o4), "" );
static_assert ( !(o4 < o5), "" );
static_assert ( !(o5 < o1), "" );
static_assert ( !(o5 < o2), "" );
static_assert ( !(o5 < o3), "" );
static_assert ( o5 < o4 , "" );
static_assert ( !(o5 < o5), "" );
}
#endif
}
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