| //===----------------------------------------------------------------------===// |
| // |
| // 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. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef TRANSPARENT_H |
| #define TRANSPARENT_H |
| |
| // testing transparent |
| #if _LIBCPP_STD_VER > 11 |
| |
| struct transparent_less |
| { |
| template <class T, class U> |
| constexpr auto operator()(T&& t, U&& u) const |
| noexcept(noexcept(std::forward<T>(t) < std::forward<U>(u))) |
| -> decltype (std::forward<T>(t) < std::forward<U>(u)) |
| { return std::forward<T>(t) < std::forward<U>(u); } |
| typedef void is_transparent; // correct |
| }; |
| |
| struct transparent_less_no_type |
| { |
| template <class T, class U> |
| constexpr auto operator()(T&& t, U&& u) const |
| noexcept(noexcept(std::forward<T>(t) < std::forward<U>(u))) |
| -> decltype (std::forward<T>(t) < std::forward<U>(u)) |
| { return std::forward<T>(t) < std::forward<U>(u); } |
| private: |
| // typedef void is_transparent; // error - should exist |
| }; |
| |
| struct transparent_less_private |
| { |
| template <class T, class U> |
| constexpr auto operator()(T&& t, U&& u) const |
| noexcept(noexcept(std::forward<T>(t) < std::forward<U>(u))) |
| -> decltype (std::forward<T>(t) < std::forward<U>(u)) |
| { return std::forward<T>(t) < std::forward<U>(u); } |
| private: |
| typedef void is_transparent; // error - should be accessible |
| }; |
| |
| struct transparent_less_not_a_type |
| { |
| template <class T, class U> |
| constexpr auto operator()(T&& t, U&& u) const |
| noexcept(noexcept(std::forward<T>(t) < std::forward<U>(u))) |
| -> decltype (std::forward<T>(t) < std::forward<U>(u)) |
| { return std::forward<T>(t) < std::forward<U>(u); } |
| |
| int is_transparent; // error - should be a type |
| }; |
| |
| struct C2Int { // comparable to int |
| C2Int() : i_(0) {} |
| C2Int(int i): i_(i) {} |
| int get () const { return i_; } |
| private: |
| int i_; |
| }; |
| |
| bool operator <(int rhs, const C2Int& lhs) { return rhs < lhs.get(); } |
| bool operator <(const C2Int& rhs, const C2Int& lhs) { return rhs.get() < lhs.get(); } |
| bool operator <(const C2Int& rhs, int lhs) { return rhs.get() < lhs; } |
| |
| #endif |
| |
| #endif // TRANSPARENT_H |