【People.h】
#ifndef PEOPLE_H_
#define PEOPLE_H_
class People: public QObject{
public:
    People(){
    }
private:
    QString name;
private:
    QString age;
public:
    QString getName() const{
        return this->name;
    }
    void setName(QString name){
        this->name = name;
    }
    QString getAge(){
        return age;
    }
    void setAge(QString age) {
        this->age = age;
    }
public:
    QString &operator<<(People stu);
    bool operator==(const People& other);
    void a();
};
#endif /* PEOPLE_H_ */
【People.cpp】
#include <People.h>
void People::a(void){
}  //这个方法正常,为什么下个方法就报错呢
QString People::&operator<<(People stu){
}   //此方法格式错误。