提升移动编译错误

Question

I'm trying to implement the move constructor outside the class body, but it won't compile correctly

#include <boost/move/move.hpp>

class Test
{
    BOOST_COPYABLE_AND_MOVABLE(Test)
public:
    Test() {}
    Test(const Test & other) { }
    Test(BOOST_RV_REF(Test) other);
    Test & operator=(BOOST_COPY_ASSIGN_REF(Test) other) { return *this; } 
    Test & operator=(BOOST_RV_REF(Test) other) { return *this; }
};

Test::Test(BOOST_RV_REF(Test) other) { }

I compiled this code with g++, my g++ version is 4.4.7

$ g++ -c test.cpp
test.cpp:15: error: prototype for 'Test::Test(boost::rv<Test>&)' does not match any in class 'Test'
test.cpp:9: error: candidates are: Test::Test(boost:rv<Test>&)
test.cpp:8: error:                 Test::Test(const Test&)
test.cpp:7: error:                 Test::Test()

Answer 1

It also failed with g++ 5.4.0 – flyzero

Must be your boost version.

It works fine with g++ 5.4.1 and Boost 1.64. If not, check the preprocessor output for any include/macro mishaps.

Answer 2

In Linux, ::boost::rv is declared with may_alias attribute. My code compile correctly after removing the may_alias attribute.

#define BOOST_MOVE_ATTRIBUTE_MAY_ALIAS __attribute__((__may_alias__))

template <class T>
class rv
    : public ::boost::move_detail::if_c
        < ::boost::move_detail::is_class<T>::value
        , T
        , ::boost::move_detail::nat
        >::type
{
    rv();
    ~rv() throw();
    rv(rv const&);
    void operator=(rv const&);
} BOOST_MOVE_ATTRIBUTE_MAY_ALIAS;