c – 从*值转换为rvalue方法？

§9.3.2[class.this] p1

In the body of a non-static (9.3) member function,the keyword this is a prvalue expression whose value is the address of the object for which the function is called. The type of this in a member function of a class X is X*. […]

§5.3.1[expr.unary.op] p1

The unary * operator performs indirection: the expression to which it is applied shall be a pointer to an object type,or a pointer to a function type and the result is an lvalue referring to the object or function to which the expression points.

所以你需要std :: move如果你想调用move构造函数.

以下代码片段显示：

#include <iostream>
#include <utility>

struct test{
  test(){}
  test(test const&){ std::cout << "copy ctor // #1\n"; }
  test(test&&){ std::cout << "move ctor // #2\n"; }

  test f_no_move() &&{ return *this; }
  test f_move() &&{ return std::move(*this); }
};

int main(){
  test().f_no_move(); // #1
  test().f_move(); // #2
}

使用Clang 3.1(我知道实现ref-qualifiers的唯一编译器),我得到以下输出：

$clang++ -std=c++0x -stdlib=libc++ -pedantic -Wall t.cpp $./a.out copy ctor // #1 move ctor // #2