本文共 2598 字，大约阅读时间需要 8 分钟。

#include 
   
    #include 
    
     using namespace std;template
     
      void valTest(T t) {    cout << "void valTest(T t)" << endl;    t++;    cout << "t = " << t << endl;}template
      
       void refTest(T& t) {    cout << "void refTest(T& t)" << endl;    t++;    cout << "t = " << t << endl;}template
       
        void moveTest(T&& t) {    cout << "void moveTest(T&& t)" << endl;    t++;    cout << "t = " << t << endl;}//总结://(1)模板参数(T t);传参时ref()的是原本，其余都是副本//(2)模板里自带引用(T& t)或者(T&& t)，无论传参的是左值还是右值，其作用都在原值上//变量、左值引用、右值引用原则上不能冲突(模板可以，没有那么严格)//ref 变量-》左值引用//mov 左值—》右值(避免拷贝)int main() {    int data = 100;    valTest(ref(data));  // ref引用传参    cout << "data = " << data << endl;  // 101    cout << "===========" << endl;                                    //data = 101    int &&rrdata = data + 1;        //rrdata = 102    valTest(rrdata);    cout << "rrdata = " << rrdata << endl;  // 102    cout << "data = " << data << endl;  // data =101    cout << "===========" << endl;    refTest(rrdata);              // rrdata = 102    cout << "rrdata = " << rrdata << endl;  // 103    cout << "data = " << data << endl;  // data =101    cout << "===========" << endl;    moveTest(/*reinterpret_cast
        
         */(rrdata)); // rrdata = 103 cout << "rrdata = " << rrdata << endl; // 104 cout << "data = " << data << endl; // data =101 cout << "===========" << endl; return 0;}int main2() { int data = 100; int &rdata = data; valTest(rdata); cout << "rdata = " << rdata << endl; // rdata = 100 cout << "data = " << data << endl; // data = 100 cout << "===========" << endl; refTest(rdata); // rdata = 100 cout << "rdata = " << rdata << endl; // rdata = 101 cout << "data = " << data << endl; // rdata = 101 cout << "===========" << endl; moveTest(/*reinterpret_cast
         
          */(rdata)); //rdata = 101 cout << "rdata = " << rdata << endl; // rdata = 102 cout << "data = " << data << endl; // data = 102 cout << "===========" << endl; //模板并没有那么严格，如果是自定义函数则无法通过编译，则需要使用move()把数据、左值引用变为右值引用// moveTest(move(rdata));// cout << "rdata = " << rdata << endl; // 103// cout << "===========" << endl; return 0;}int main1() { int data = 100; valTest(data); cout << "data = " << data << endl; // 100 cout << "===========" << endl; refTest(data); cout << "data = " << data << endl; // 101 cout << "===========" << endl; moveTest(/*reinterpret_cast
          
           */(data)); cout << "data = " << data << endl; // 102 cout << "===========" << endl; return 0;}
          
         
        
       
      
     
    
   

std::ref 用于包装按引用传递的值。

std::move并不能移动任何内存，它唯一的功能是将一个左值强制转化为右值引用，继而可以通过右值引用使用该值，以用于移动语义,从实现上讲，std::move基本等同于一个类型转换：static_cast<T&&>(lvalue);

转载地址：https://jadeshu.blog.csdn.net/article/details/107227949 如侵犯您的版权，请留言回复原文章的地址，我们会给您删除此文章，给您带来不便请您谅解！