99.重载[] * -> ->*

 #include "mainwindow.h"
 #include <QApplication>
 #include <QPushButton>>

 //重载的三种形式,成员函数重载
 //友元函数重载,可以使用私有变量以及保护变量
 //一般函数重载都是公有变量

 class buttons
 {
     QPushButton *p;
     int n;

 public:
     buttons():n()
     {
         p = new QPushButton[];
         for(int i=;i<;i++)
         {
             p[i].resize(,);
             p[i].move(i*,i*);
             p[i].show();
         }
     }
     ~buttons()
     {
         delete[] p;
     }

     //重载[]
     QPushButton *operator [](int i)
     {
         if(i>= && i<=n-)
         {
             return this->p+i;
         }
     }

     //重载*
     QPushButton *operator *()
     {
          return this->p;
     }

     //重载->
     QPushButton *operator ->()
     {
          return this->p+;
     }

     //重载->*
     QPushButton *operator ->*(int i)
     {
          return this->p+i;
     }
 };

 int main(int argc, char *argv[])
 {
     QApplication a(argc, argv);

     buttons bs;
    // bs[3]->hide();
    // (*bs+2)->hide();
     //bs->hide();
    // bs->*hide();
     (bs->*)->hide();
     return a.exec();
 }