错误：运营商“＆gt;＆gt;”不匹配在Qt

Question

我编写了一个客户端GUI来接收来自服务器的结构。编译时，我收到错误：

  

错误：“operator>>”

中的“is >> newstruct.basestruct::element1”不匹配

你能指出我出错的地方吗？

dialog.cpp：

#include "dialog.h"
#include "ui_dialog.h"
#include <QString>
#include <QDebug>
#include <QTextStream>
#include <QDataStream>

Dialog::Dialog(QWidget *parent) :
    QDialog(parent),
    ui(new Ui::Dialog)
{
    ui->setupUi(this);
    ui->pushButton->setText("Connect");
    ui->pushButton_2->setText("Ok");
    ui->pushButton_3->setText("Close");
    ui->pushButton_4->setText("Disconnect");
}

Dialog::~Dialog()
{
    delete ui;
}
QDataStream& operator >>(QDataStream& is,const basestruct& newstruct)
{
    is >> newstruct.element1;
    qDebug()<<newstruct.element1;

}
void Dialog::Read()
{
    socket->waitForReadyRead(-1);
    QDataStream receiveData(socket);
    receiveData.setVersion(QDataStream::Qt_4_0);
    receiveData >>newstruct ;
}
void Dialog::on_pushButton_clicked()
{
    socket=new QTcpSocket(this);
    socket->connectToHost("127.0.0.1",5000);
    if (socket->waitForConnected(-1))
        qDebug()<<"Connected";
    Read();
}
void Dialog::on_pushButton_4_clicked()
{
    socket->close();
    qDebug()<<"Disconnected";
}

dialog.h：

#ifndef DIALOG_H
#define DIALOG_H

#include <QDialog>

#include <QTcpSocket>

namespace Ui {
    class Dialog;
}

struct basestruct
{
    int element1;
    int element2;
};

class Dialog : public QDialog
{
    Q_OBJECT

public:
    explicit Dialog(QWidget *parent = 0);
    ~Dialog();
    void Read();

private slots:
    void on_pushButton_clicked();

    void on_pushButton_4_clicked();

private:
    Ui::Dialog *ui;
    QTcpSocket *socket;
    friend  Q_CORE_EXPORT QDataStream &operator >>(QDataStream&,const struct basestruct&);
    struct basestruct newstruct;
};

#endif // DIALOG_H