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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.
//
//===----------------------------------------------------------------------===//
// 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)), ""); // equal
static_assert(!(o3 < T(1)), "");
static_assert((o2 < val), "");
static_assert(!(o3 < val), ""); // equal
static_assert((o3 < T(3)), "");
static_assert(!(T(1) < o1), "");
static_assert(!(T(1) < o2), ""); // equal
static_assert((T(1) < o3), "");
static_assert(!(val < o2), "");
static_assert(!(val < o3), ""); // equal
static_assert(!(T(3) < o3), "");
}
{
using O = optional<int>;
constexpr O o1(42);
static_assert(o1 < 101l, "");
static_assert(!(42l < o1), "");
}
{
using O = optional<const int>;
constexpr O o1(42);
static_assert(o1 < 101, "");
static_assert(!(42 < o1), "");
}
}
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