C++在类的定义内部使用该类定义变量会怎样

C++
在类的内部使用该类：
[code=c++]
class A
{
private: A b;
int c;
};
A abc;
[/code]
像这样，变量adc在实例的时候内存计算（一层层迭代，无穷无尽）后岂不是无穷大了？有或不能这样用？
希望有人帮本人解答这个疑问

解决方案

这是不允许的。
9.2 Class Members
2 A class is considered a completely-defined object type (3.9) (or complete type) at the closing } of the
class-specifier. Within the class member-specification, the class is regarded as complete within function
bodies, default arguments, exception-specifications, and brace-or-equal-initializers for non-static data members (including such things in nested classes). Otherwise it is regarded as incomplete within its own class
member-specification.
10 Non-static (9.4) data members shall not have incomplete types. In particular, a class C shall not contain
a non-static member of class C, but it can contain a pointer or reference to an object of class C.

无限递归构造会死的，编译器也能检查出来，报错

类中不能申明该类的变量，否则你不能通过编译，但可以声明该类指针型变量

c++编译器已经考虑到这个无限递归的问题了，所以它根本不允许这种语法的出现，下图就是本人测试的结果：
C++在类的定义内部使用该类定义变量会怎样