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> constexpr bool operator==(const optional<T>& x, const T& v); 14 // template <class T> constexpr bool operator==(const T& v, const optional<T>& x); 15 16 #include <optional> 17 18 using std::optional; 19 20 struct X 21 { 22 int i_; 23 24 constexpr X(int i) : i_(i) {} 25 }; 26 27 constexpr bool operator == ( const X &lhs, const X &rhs ) 28 { return lhs.i_ == rhs.i_ ; } 29 30 int main() 31 { 32 { 33 typedef X T; 34 typedef optional<T> O; 35 36 constexpr T val(2); 37 constexpr O o1; // disengaged 38 constexpr O o2{1}; // engaged 39 constexpr O o3{val}; // engaged 40 41 static_assert ( !(o1 == T(1)), "" ); 42 static_assert ( (o2 == T(1)), "" ); 43 static_assert ( !(o3 == T(1)), "" ); 44 static_assert ( (o3 == T(2)), "" ); 45 static_assert ( (o3 == val), "" ); 46 47 static_assert ( !(T(1) == o1), "" ); 48 static_assert ( (T(1) == o2), "" ); 49 static_assert ( !(T(1) == o3), "" ); 50 static_assert ( (T(2) == o3), "" ); 51 static_assert ( (val == o3), "" ); 52 } 53 } 54
