C++ '' 的构造函数必须显式初始化引用成员 ''
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Constructor for '' must explicitly initialize the reference member ''
提问by clankill3r
I have this class
我有这堂课
class CamFeed {
public:
// constructor
CamFeed(ofVideoGrabber &cam);
ofVideoGrabber &cam;
};
And this constructor:
而这个构造函数：
CamFeed::CamFeed(ofVideoGrabber &cam) {
this->cam = cam;
}
I get this error on the constructor: Constructor for '' must explicitly initialize the reference member ''
我在构造函数上收到此错误：''的构造 函数必须显式初始化引用成员 ''
What is a good way to get around this?
解决这个问题的好方法是什么？
回答by juanchopanza
You need to use the constructor initializer list:
您需要使用构造函数初始值设定项列表：
CamFeed::CamFeed(ofVideoGrabber& cam) : cam(cam) {}
This is because references must refer to something and therefore cannot be default constructed. Once you are in the constructor body, all your data members have been initialized. Your this->cam = cam;line would really be an assignment, assigning the value referred to by camto whatever this->camrefers to.
这是因为引用必须引用某些东西，因此不能默认构造。进入构造函数体后，所有数据成员都已初始化。您的this->cam = cam;行实际上是一个分配，将引用的值分配给引用的cam任何内容this->cam。
