Rvalue引用不适用于Mac OS X 10.7.4和FreeBSD 9.0

这是我的代码

#include <iostream>
#include <vector>
int main()
{
  std::vector<size_t> v1, v2;
  v1.push_back(3);
  v1.push_back(4);
  v2 = static_cast<std::vector<size_t>&&>(v1);
  std::cout << v1.size() << '\n';
  std::cout << v2.size() << '\n';  
}

当我使用GCC 4.7.0或者使用--std = c 0x的clang 3.1在Linux上编译代码时，它输出0和2.但是，当我使用任何一个clang在Mac OS X 10.7.4或FreeBSD 9.0上编译代码时3.0或clang 3.1与--std = c 0x，输出2和2.我的Mac OS X和FreeBSD上的GCC是v4.2.1，它不支持--std = c 0x . 所以我使用了Boost.Move：

#include <boost/move/move.hpp>
v2 = boost::move(v1);

当我使用带有-I~ / boost_1_49_0的GCC 4.2.1在Mac OS X上编译代码时，它仍然输出2和2 .

Updated: 当我添加--stdlib = libc时，代码输出0和2.右值引用似乎正常工作 . 但是，当我将矢量类型从size_t更改为string时，我得到了编译错误，即使我评论了最后三行代码 . 这次问题与Rvalue引用无关，但来自push_back（）函数 . 当我删除--stdlib = libc时，它可以通过编译 .

#include <iostream>
#include <string>
#include <vector>
int main()
{
  std::vector<std::string> v1, v2;
  v1.push_back("hello");
  /*
  v2 = static_cast<std::vector<std::string>&&>(v1);
  std::cout << v1.size() << '\n';
  std::cout << v2.size() << '\n';  
  */
}

哪个铿锵

/uac/gds/hjli/clang+llvm-3.1-x86_64-apple-darwin11/bin/clang

clang --std = c 11 --stdlib = libc rval.cpp

In file included from rval.cpp:1:
In file included from /usr/include/c++/v1/iostream:38:
In file included from /usr/include/c++/v1/ios:216:
In file included from /usr/include/c++/v1/__locale:15:
/usr/include/c++/v1/string:1952:10: error: overload resolution selected
      implicitly-deleted copy assignment operator
    __r_ = _STD::move(__str.__r_);
         ^
/usr/include/c++/v1/string:1942:9: note: in instantiation of member function
      'std::__1::basic_string<char, std::__1::char_traits<char>,
      std::__1::allocator<char> >::__move_assign' requested here
        __move_assign(__str, true_type());
        ^
/usr/include/c++/v1/string:1961:5: note: in instantiation of member function
      'std::__1::basic_string<char, std::__1::char_traits<char>,
      std::__1::allocator<char> >::__move_assign' requested here
    __move_assign(__str, integral_constant<bool,
    ^
/usr/include/c++/v1/algorithm:1595:19: note: in instantiation of member function
      'std::__1::basic_string<char, std::__1::char_traits<char>,
      std::__1::allocator<char> >::operator=' requested here
        *__result = _STD::move(*__first);
                  ^
/usr/include/c++/v1/algorithm:1619:12: note: in instantiation of function
      template specialization 'std::__1::__move<std::__1::basic_string<char> *,
      std::__1::basic_string<char> *>' requested here
    return _STD::__move(__unwrap_iter(__first), __unwrap_iter(__last),...
           ^
/usr/include/c++/v1/__config:153:14: note: expanded from macro '_STD'
#define _STD std::_LIBCPP_NAMESPACE
             ^
/usr/include/c++/v1/__split_buffer:557:22: note: in instantiation of function
      template specialization 'std::__1::move<std::__1::basic_string<char> *,
      std::__1::basic_string<char> *>' requested here
            __end_ = _STD::move(__begin_, __end_, __begin_ - __d);
                     ^
/usr/include/c++/v1/__config:153:14: note: expanded from macro '_STD'
#define _STD std::_LIBCPP_NAMESPACE
             ^
/usr/include/c++/v1/vector:1289:13: note: in instantiation of member function
      'std::__1::__split_buffer<std::__1::basic_string<char>,
      std::__1::allocator<std::__1::basic_string<char> > &>::push_back'
      requested here
        __v.push_back(_STD::move(__x));
            ^
rval.cpp:10:5: note: in instantiation of member function
      'std::__1::vector<std::__1::basic_string<char>,
      std::__1::allocator<std::__1::basic_string<char> > >::push_back' requested
      here
        v1.push_back("nice");
           ^
/usr/include/c++/v1/memory:1941:5: note: copy assignment operator is implicitly
      deleted because '__compressed_pair<std::__1::basic_string<char,
      std::__1::char_traits<char>, std::__1::allocator<char> >::__rep,
      std::__1::allocator<char> >' has a user-declared move constructor
    __compressed_pair(__compressed_pair&& __p)
    ^
1 error generated.