Code generated by a client's compiler can freely access all these tables through the vtable pointer, which is always located in the first 4 bytes of the memory image of the object.

客户端编译生成的代码能够自由存取vtable指针里的所有表，vtable始终在对象的内存映象的前4个字节里。

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It obtains the pointer to the vtable of the class from the first 4 bytes of the object's instance data.

它包含类的vtable表的指针，包含位置是在对象实例数据的前4字节里。

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The memory image of an instance of a class has one pointer to the vtable of this class, stored in front of the actual data members of the object.

类的实例的内存快照里有一个vtable的指针，该指针位置在实际的成员变量前面。

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