错误:将"const std :: __ cxx11 :: list<>"作为“此"参数传递会丢弃限定符 [英] error: passing ‘const std::__cxx11::list<>’ as ‘this’ argument discards qualifiers

问题描述

我有一个小问题，找不到解决方法.

I have a little problem and can't find a way to fix it..

在我的.hpp文件中，我声明了这两个函数和struct，但是由于此"参数放弃了限定词，因此出现了通过const std :: __ cxx11 :: list<>传递错误"的错误.

In my .hpp file I have declared these two functions and struct but getting the error 'passing ‘const std::__cxx11::list<>’ as ‘this’ argument discards qualifiers.'

struct Student {
    std::string name;
    std::string student_id;

};

class StudentRegistry {

public:
    StudentRegistry(){}
    void Add(const Student &t);
    const std::list<Student>& GetStudents() const;

private:
    std::list<Student> students;
};

在.cpp文件中，我尝试执行以下操作:

And in .cpp file I have tried to do:

void StudentRegistry::Add(const Student &t){
    this->GetStudents().push_back(t);
}

const std::list<Student>& StudentRegistry::GetStudents() const{
    return students;
}

我该如何进行这项工作?

How can I make this work?

推荐答案

const std::list<Student>& GetStudents() const;

和

this->GetStudents().push_back(t);

有冲突.您有不修改从 GetStudents()中获得的列表的合同，但是您尝试使用 push_back 来做到这一点.

are in conflict. You have a contract to not modify the list you get from GetStudents(), but you try to do that with push_back.

解决方案:

void StudentRegistry::Add(const Student& t) {
    students.push_back(t);
}

这篇关于错误:将"const std :: __ cxx11 :: list&lt;&gt;"作为“此"参数传递会丢弃限定符的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！