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//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
// UNSUPPORTED: c++98, c++03, c++11, c++14
// <optional>
// template <class T, class U> constexpr bool operator< (const optional<T>& x, const optional<U>& y);
#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 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), "");
}
{
using O1 = optional<int>;
using O2 = optional<long>;
constexpr O1 o1(42);
static_assert(o1 < O2(101), "");
static_assert(!(O2(101) < o1), "");
}
{
using O1 = optional<int>;
using O2 = optional<const int>;
constexpr O1 o1(42);
static_assert(o1 < O2(101), "");
static_assert(!(O2(101) < o1), "");
}
}
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