c++ - 对类型的临时类型的非常量引用的初始化无效

Question

我的类结构如下:

Test_Camera.h:

class Test_Camera : public Camera_Interface {
public:
   Test_Camera (string const& aName);
   ...

测试相机.cpp

Test_Camera::Test_Camera(string const& aName) : Camera_Interface(0, 0, 0, 0), name(aName)

在实例化 Test_Camera 对象的代码中，我有 2 个场景。第一个编译正常，但第二个没有，我不明白为什么。

Test_Camera cam ("cam"); // This compiles

Test_Camera& cam ("cam"); // This does not compile

当我尝试编译第二个示例时出现错误:

error: invalid initialization of non-const reference to type 'Test_Camera&' from a temporary of type 'const char*'

我也试过:

string name = "cam";
Test_Camera& cam (name); //does not compile

Answer 1

引用应该引用一个现有的对象:

Test_Camera cam ("cam");
Test_Camera &cam_ref = cam;