Question

I was wondering how I can use the sort function to sort a vector which is private in a class:

#include <iostream>
#include <string>
#include <vector>
#include <algorithm>


using namespace std;

class A{
private:
    const vector<int> myvec;
    A(vector<int>& vec) : myvec(vec) { }

public:
    const vector<int>& getvec() { return myvec; }

    int get_sec_element(){
        int sec_ele = 0;

        sort(myvec.begin(), myvec.end());

        sec_ele = myvec[2];
        return sec_ele;
    }
};

So if I created A myvec_object and filled it with a vector which had values already inside it, caliing myvec_object.get_sec_ele() would return the 2nd element in the vector. However, the compiler is giving a huge error message with: “instantiated from here”. What could be the problem?

Answer 1

You declared myvec as const — how would you expect to modify it?

Declare myvec as:

vector<int> myvec;