#include <vector>
#include <string>
#include <iostream>

class student {
  public:
    std::string name;
    int age;

    student(const std::string & _name, const int & _age): name(_name), age(_age){}
};

int main()
{
  std::vector<student> student_vec;
  student_vec.emplace_back(student("mary", 15));
  student_vec.emplace_back(student("mike", 17));
  student_vec.emplace_back(student("tom", 16));
  std::vector<student> student_vec_move;
  std::cout << "student_vec" << std::endl;
  for (auto & s : student_vec)  //xxx
  {
      std::cout << s.name << "    " << s.age << "\t" << &s << std::endl;
      student_vec_move.emplace_back(std::move(s));
  }

  std::cout << "student_vec: after std::move" << std::endl;
  for (const auto & s : student_vec)
  {
      std::cout << s.name << "    " << s.age << "\t" << &s << std::endl;
  }

  std::cout << "student_vec_move" << std::endl;
  for (auto & s : student_vec_move)
  {
      std::cout << s.name << "    " << s.age << "\t" << &s << std::endl;
      s.name = s.name + "++";
  }

  std::cout << "student_vec_move: after modify" << std::endl;
  for (auto & s : student_vec_move)
  {
      std::cout << s.name << "    " << s.age << "\t" << &s << std::endl;
  }

  std::cout << "student_vec: after modify" << std::endl;
  for (const auto & s : student_vec)
  {
      std::cout << s.name << "    " << s.age << "\t" << &s << std::endl;
  }
}

运行结果

student_vec
mary    15      0x25a70f0
mike    17      0x25a7100
tom     16      0x25a7110
student_vec: after std::move
        15      0x25a70f0
        17      0x25a7100
        16      0x25a7110
student_vec_move
mary    15      0x25a7140
mike    17      0x25a7150
tom     16      0x25a7160
student_vec_move: after modify
mary++  15      0x25a7140
mike++  17      0x25a7150
tom++   16      0x25a7160
student_vec: after modify
        15      0x25a70f0
        17      0x25a7100
        16      0x25a7110

说明
1、使用std::move操作vector元素时，原vector元素将不再可用，但原vector可以正常遍历。因为std::move操作的是元素中的具体成员，而非元素整体，所以新vector元素的地址与原vector元素是不同的
2、std::move只会操作class类型的成员，而不会操作基本类型，示例中age成员仍得到保留
3、如果将“//xxx”行加个const改为

for (const auto & s : student_vec)  //xxx

则输出为

student_vec
mary    15      0x217b0f0
mike    17      0x217b100
tom     16      0x217b110
student_vec: after std::move
mary    15      0x217b0f0
mike    17      0x217b100
tom     16      0x217b110
student_vec_move
mary    15      0x217b140
mike    17      0x217b150
tom     16      0x217b160
student_vec_move: after modify
mary++  15      0x217b140
mike++  17      0x217b150
tom++   16      0x217b160
student_vec: after modify
mary    15      0x217b0f0
mike    17      0x217b100
tom     16      0x217b110

说明，std::move对vector元素的操作无效，仍然调用了内存拷贝