libcxx/test/std/utilities/optional/optional.comp_with_t/less_equal.pass.cpp

//===----------------------------------------------------------------------===//
//
//                     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> 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>

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), "" );
    }
}