C++ noob - 类作用域

Question

我有以下 C++ 类:

class Eamorr {
public:
        redispp::Connection conn;

        Eamorr(string& home, string& uuid)
        {
            //redispp::Connection conn("127.0.0.1", "6379", "password", false);   //this works, but is out of scope in put()...
            conn=new redispp::Connection("127.0.0.1", "6379", "password", false);   //this doesn't work ;(
        }
        put(){
            conn.set("hello", "world");
        }
        ...
}

如您所见，我希望 conn 在构造函数中初始化并在 put() 方法中可用。

我该怎么做？

非常感谢，

Answer 1

这就是成员初始化列表的用途:

 Eamorr(string& home, string& uuid) 
     : conn("127.0.0.1", "6379", "password", false) 
 {
    //constructor body!
 }

: 之后的语法(包括这个)构成了 member-initiazation-list。您可以在这里初始化成员，每个成员用逗号分隔。

这是一个详细的例子:

struct A
{
     int n;
     std::string s;
     B *pB;

     A() : n(100), s("some string"), pB(new B(n, s))
     {
        //ctor-body!
     }
};

有关更多信息，请参阅这些:

• Why should I prefer to use member initialization list?
• Should my constructors use "initialization lists" or "assignment"? (常见问题解答)