33 lines · cpp
1// RUN: %clang_cc1 -fsyntax-only %s -std=c++98 -verify2// expected-no-diagnostics3 4// This is a test for a hack in Clang that works around an issue with libc++5// 3.1's std::move and std::forward implementation. When emulating these6// functions in C++98 mode, libc++ 3.1 has a "fake rvalue reference" type, and7// std::move will return by value when given an instance of that type.8 9namespace std {10 struct rv {};11 12 template<bool B, typename T> struct enable_if;13 template<typename T> struct enable_if<true, T> { typedef T type; };14 15 template<typename T> typename enable_if<__is_convertible(T, rv), T>::type move(T &);16 template<typename T> typename enable_if<!__is_convertible(T, rv), T&>::type move(T &);17 18 template<typename U, typename T> typename enable_if<__is_convertible(T, rv), U>::type forward(T &);19 template<typename U, typename T> typename enable_if<!__is_convertible(T, rv), U&>::type forward(T &);20}21 22struct A {};23void f(A a, std::rv rv) {24 a = std::move(a);25 rv = std::move(rv);26 27 a = std::forward<A>(a);28 rv = std::forward<std::rv>(rv);29 30 a = std::forward<A&>(a);31 rv = std::forward<std::rv&>(rv);32}33