| //===----------------------------------------------------------------------===// | 
 | // | 
 | //                     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 | 
 | // <optional> | 
 |  | 
 | // template <class T> constexpr bool operator<= (const optional<T>& x, const optional<T>& y); | 
 |  | 
 | #include <experimental/optional> | 
 |  | 
 | 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_ ; } | 
 |  | 
 | 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), "" ); | 
 |     } | 
 | } |