Public struct inside a class and scopes

Question

Let's say I have the following code in a header:

class A {
 public:
  struct B {...}
  ...
}

Shouldn't I be able to make this declaration in a source that includes the above header file:

 ...
B structb;
 ...

without having to declare the scope I'm using? (A::B structb)

Thanks a lot.

Answer 1

通过显示的代码，它意味着B是A内的结构，就像A的任何其他属性一样。因此，如果不使用范围解析，就无法声明或使用该变量。