less_than.pass.cpp revision 0cdbe6048173c1f05628dbc85430acf191a3e173 
1//===----------------------------------------------------------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is dual licensed under the MIT and the University of Illinois Open
6// Source Licenses. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9
10// <optional>
11
12// template <class T> constexpr bool operator<(const optional<T>& x, const T& v);
13// template <class T> constexpr bool operator<(const T& v, const optional<T>& x);
14
15#include <experimental/optional>
16
17#if _LIBCPP_STD_VER > 11
18
19using std::experimental::optional;
20
21struct X
22{
23    int i_;
24
25    constexpr X(int i) : i_(i) {}
26};
27
28constexpr bool operator < ( const X &lhs, const X &rhs )
29    { return lhs.i_ < rhs.i_ ; }
30
31#endif
32
33int main()
34{
35#if _LIBCPP_STD_VER > 11
36
37    {
38    typedef X T;
39    typedef optional<T> O;
40
41    constexpr T val(2);
42    constexpr O o1;     // disengaged
43    constexpr O o2{1};  // engaged
44    constexpr O o3{val};  // engaged
45
46    static_assert (   o1 < T(1) , "" );
47    static_assert ( !(o2 < T(1)), "" );
48    static_assert ( !(o3 < T(1)), "" );
49    static_assert (   o2 < T(2) , "" );
50    static_assert (   o2 < T(val), "" );
51    static_assert (   o3 < T(3) , "" );
52
53    static_assert (  !(T(1) < o1), "" );
54    static_assert (  !(T(1) < o2), "" );
55    static_assert (    T(1) < o3 , "" );
56    static_assert (  !(T(2) < o2), "" );
57    static_assert (!(T(val) < o2), "" );
58    static_assert (  !(T(3) < o3), "" );
59    }
60#endif
61}
62