使用vector :: push_back()方法时C++向量编译错误

Question

我在我的程序中使用std :: vector,编译时出现此错误:

/usr/lib/gcc/i686-pc-cygwin/3.4.4/include/c++/bits/vector.tcc:在成员函数`User&User :: operator =(const User&)'中:

/usr/lib/gcc/i686-pc-cygwin/3.4.4/include/c++/bits/vector.tcc:238:从void std::vector<_Tp, _Alloc>::_M_insert_aux(__gnu_cxx::__normal_iterator<typename _Alloc::pointer, std::vector<_Tp, _Alloc> >, const _Tp&) [with _Tp = User, _Alloc = std::allocator<User>]' /usr/lib/gcc/i686-pc-cygwin/3.4.4/include/c++/bits/stl_vector.h:564: instantiated fromvoid std :: vector <_Tp,_Alloc> :: push_back(const _Tp&)实例化[与_Tp = User,_Alloc = std :: allocator]'

main.cpp:100:从这里实例化

/usr/lib/gcc/i686-pc-cygwin/3.4.4/include/c++/bits/vector.tcc:238:错误:非静态const成员`const std :: string User :: NAME',can'使用默认赋值运算符

我有"用户"和"用户"类:

class User {
    public:
        const string NAME;

        User(const string &name, const bool &isMain = false) : NAME(name), isMain(isMain) {};
        void addFollower(User * user);
        void addReplier(User * user, const int &count);
        void addMentioner(User * user, const int &count);
        void addRetweeter(User * user, const int &count);

    private:
        vector<User *> followedBy, repliedBy, mentionedBy, retweetedBy;
        vector<int> replyCount, mentionCount, retweetCount;
        bool isMain;
    };


class Users {
    public:
        vector<User> users;

        void addUser(const string &name, bool isMain = false);
        User * findUser(const string &name);
        friend ostream & operator <<(ostream &outStream, const Users &users);
        User & operator [] (unsigned int index);
    };

这就是事情.该错误是由Users :: addUser()方法引起的:

void Users::addUser(const string &name, bool isMain) {
    User newUser(name, isMain);
    users.push_back(newUser);
}

如果我删除第二行

users.push_back(newUser);

它运行正常,但是,它不像你看到的那样工作,因为它阻止我将新记录添加到"users"向量数组中.如果有人告诉我原因是什么,我会感恩的.谢谢

Answer 1

您必须提供复制构造函数才能使用push_back,因为您的类包含非静态const成员.

您可以使用getter轻松解决此问题:

class User{
public:
    string NAME() const { return m_name; }
    /* ... */
private:
    string m_name;
    /* ... */
};