struct

struct BiNode *lchild,*rchild;

//左右孩子指针；

When you access the struct through the interface pointer, you don't have to unbox the struct to access that object.

当你通过指针访问时候，没必要对结构体进行拆箱后再访问那个对象。为举例，想象该结构体定义一个链和一个描。