没有匹配的函数来调用getline（）

Question

so i am working on something and i cant seem to get why it isn't working.

void display_alls()
{
    ifstream fpd;
    fpd.open("student2.txt",ios::in);
    if(!fpd)
    {
        cout<<"ERROR!!! FILE COULD NOT BE OPEN ";
        getch();
        return;
    }
    while(fpd)
    {   
        int pos;
        string seg;

        cout<<"\tUSN"<<setw(10)<<"\tName"<<setw(20)<<"Book Issued\n";
        //fp.seekg(pos,ios::beg);

        getline(fpd,st.usn,'|');
        getline(fpd,st.name,'|');
        getline(fpd,st.email,'|');
        getline(fpd,st.phone,'|');
        getline(fpd,st.stbno,'|');
        getline(fpd,seg);

        cout<<"\t"<<st.usn<<setw(20)<<st.name<<setw(10)<<st.stbno<<endl;
    }
    fp.close();
}

[Error] D:\\library\\library_v1.cpp:514: error: no matching function for call to `getline(std::ifstream&, char[20], char)'

error is on each line with getline ! but not in " getline(fpd,seg); "

this thing isn't working on MingW compiler but was working on my college system, idk maybe they are having older compiler, can you please tell me what is wrong. much appreciated.

Answer 1

std::getline , if that's what you're trying to use, is defined in the <string> header. You will want to include it:

#include <string>

Then you can call it via std::getline . If you get tired of typing std:: , you can do:

using namespace std;

Depending on the IDE or build setup, these things can sometimes be done for you already. It's possible that is why this works on the school computer, but not yours.

Answer 2

The error message suggests that the code is attempting to read into an array of 20 characters. Unfortunately std::getline does not deal in character arrays. It only reads into std::string , which is why it works with string seg; For character arrays you need to use std::istream::getline . Link to documentation page

However life will probably be easier for you if you can replace the character arrays in the data structure with std::string s.