| Marshall Clow | 5b03e1a | 2015-06-30 18:16:12 +0000 | [diff] [blame] | 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 | #ifndef TRANSPARENT_H |
| 11 | #define TRANSPARENT_H |
| 12 | |
| 13 | // testing transparent |
| 14 | #if _LIBCPP_STD_VER > 11 |
| 15 | |
| 16 | struct transparent_less |
| 17 | { |
| 18 | template <class T, class U> |
| 19 | constexpr auto operator()(T&& t, U&& u) const |
| 20 | noexcept(noexcept(std::forward<T>(t) < std::forward<U>(u))) |
| 21 | -> decltype (std::forward<T>(t) < std::forward<U>(u)) |
| 22 | { return std::forward<T>(t) < std::forward<U>(u); } |
| 23 | typedef void is_transparent; // correct |
| 24 | }; |
| 25 | |
| 26 | struct transparent_less_no_type |
| 27 | { |
| 28 | template <class T, class U> |
| 29 | constexpr auto operator()(T&& t, U&& u) const |
| 30 | noexcept(noexcept(std::forward<T>(t) < std::forward<U>(u))) |
| 31 | -> decltype (std::forward<T>(t) < std::forward<U>(u)) |
| 32 | { return std::forward<T>(t) < std::forward<U>(u); } |
| 33 | private: |
| 34 | // typedef void is_transparent; // error - should exist |
| 35 | }; |
| 36 | |
| 37 | struct transparent_less_private |
| 38 | { |
| 39 | template <class T, class U> |
| 40 | constexpr auto operator()(T&& t, U&& u) const |
| 41 | noexcept(noexcept(std::forward<T>(t) < std::forward<U>(u))) |
| 42 | -> decltype (std::forward<T>(t) < std::forward<U>(u)) |
| 43 | { return std::forward<T>(t) < std::forward<U>(u); } |
| 44 | private: |
| 45 | typedef void is_transparent; // error - should be accessible |
| 46 | }; |
| 47 | |
| 48 | struct transparent_less_not_a_type |
| 49 | { |
| 50 | template <class T, class U> |
| 51 | constexpr auto operator()(T&& t, U&& u) const |
| 52 | noexcept(noexcept(std::forward<T>(t) < std::forward<U>(u))) |
| 53 | -> decltype (std::forward<T>(t) < std::forward<U>(u)) |
| 54 | { return std::forward<T>(t) < std::forward<U>(u); } |
| 55 | |
| 56 | int is_transparent; // error - should be a type |
| 57 | }; |
| 58 | |
| 59 | struct C2Int { // comparable to int |
| 60 | C2Int() : i_(0) {} |
| 61 | C2Int(int i): i_(i) {} |
| 62 | int get () const { return i_; } |
| 63 | private: |
| 64 | int i_; |
| 65 | }; |
| 66 | |
| 67 | bool operator <(int rhs, const C2Int& lhs) { return rhs < lhs.get(); } |
| 68 | bool operator <(const C2Int& rhs, const C2Int& lhs) { return rhs.get() < lhs.get(); } |
| 69 | bool operator <(const C2Int& rhs, int lhs) { return rhs.get() < lhs; } |
| 70 | |
| 71 | #endif |
| 72 | |
| 73 | #endif // TRANSPARENT_H |