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 // UNSUPPORTED: c++98, c++03, c++11, c++14 11 // <optional> 12 13 // template <class T, class U> constexpr bool operator<(const optional<T>& x, const U& v); 14 // template <class T, class U> constexpr bool operator<(const U& v, const optional<T>& x); 15 16 #include <optional> 17 18 using std::optional; 19 20 struct X { 21 int i_; 22 23 constexpr X(int i) : i_(i) {} 24 }; 25 26 constexpr bool operator<(const X& lhs, const X& rhs) { return lhs.i_ < rhs.i_; } 27 28 int main() { 29 { 30 typedef X T; 31 typedef optional<T> O; 32 33 constexpr T val(2); 34 constexpr O o1; // disengaged 35 constexpr O o2{1}; // engaged 36 constexpr O o3{val}; // engaged 37 38 static_assert((o1 < T(1)), ""); 39 static_assert(!(o2 < T(1)), ""); // equal 40 static_assert(!(o3 < T(1)), ""); 41 static_assert((o2 < val), ""); 42 static_assert(!(o3 < val), ""); // equal 43 static_assert((o3 < T(3)), ""); 44 45 static_assert(!(T(1) < o1), ""); 46 static_assert(!(T(1) < o2), ""); // equal 47 static_assert((T(1) < o3), ""); 48 static_assert(!(val < o2), ""); 49 static_assert(!(val < o3), ""); // equal 50 static_assert(!(T(3) < o3), ""); 51 } 52 { 53 using O = optional<int>; 54 constexpr O o1(42); 55 static_assert(o1 < 101l, ""); 56 static_assert(!(42l < o1), ""); 57 } 58 { 59 using O = optional<const int>; 60 constexpr O o1(42); 61 static_assert(o1 < 101, ""); 62 static_assert(!(42 < o1), ""); 63 } 64 } 65
