Why can't I delete list object in C++? [closed] - c++

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I tried my best to figure this out but it was unsuccessful :C
PROBLEM
for (Treniruote& t : treniruotes)
{
if (t.data == duotaData)
{
if (t.laikas == duotasLaikas)
{
treniruotes.remove(t);
}
}
}
FULL CODE:
#include <iostream>
#include <fstream>
#include <string>
#include <vector>
#include <sstream>
#include <list>
#include <ctime>
using namespace std;
struct Treniruote
{
string data, laikas, vardas, pavarde, pratimai;
};
void NuskaitytiIsFailo(list<Treniruote>& treniruotes)
{
string line, word;
fstream file("planas.csv", ios::in);
if (file.is_open())
{
while (getline(file, line))
{
stringstream str(line);
Treniruote row;
if (getline(str, word, ','))
row.data = word;
if (getline(str, word, ','))
row.laikas = word;
if (getline(str, word, ','))
row.vardas = word;
if (getline(str, word, ','))
row.pavarde = word;
if (getline(str, word, ','))
row.pratimai = word;
treniruotes.push_back(row);
}
}
else
cout << "Could not open the file";
}
void rastiKlientoInfo(list<Treniruote>& treniruotes)
{
int a;
string fname, pavarde;
cout << "Write clients surname:";
cin >> pavarde;
cout << "Output to the screen press -1\n";
cout << "Output to the file press - 2\n";
cout << "Output all exercise needed to be done in a week - 3\n";
cout << "Your choice:";
cin >> a;
if (a == 2)
{
cout << "Enter the file name: ";
cin >> fname;
}
else if (a == 3)
{
cout << "Enter the file name: ";
cin >> fname;
}
else
{
}
for (Treniruote& t : treniruotes)
{
if (t.pavarde == pavarde)
{
if (a == 1)
{
cout << t.data << endl;
cout << t.laikas << endl;
cout << t.vardas << endl;
cout << t.pavarde << endl;
cout << t.pratimai << endl;
cout << endl;
}
else if (a == 3)
{
fstream file(fname + ".csv", ios::app);
file << t.pratimai << endl;
}
else
{
fstream file(fname + ".csv", ios::app);
file << t.data << endl;
file << t.laikas << endl;
file << t.vardas << endl;
file << t.pavarde << endl;
file << t.pratimai << endl;
file << endl;
}
}
}
}
void PakeistiReiksmes(list<Treniruote>& treniruotes)
{
string duotasLaikas, duotaData;
cout << "irasykite norima data ir laika ,kada norite pakeisti duomenys" << endl;
cout << "data(formatas(XXXX.XX.XX)):";
cin >>duotaData;
cout << endl;
cout << "laikas(formatas(XX:XX-XX:XX)):";
cin >>duotasLaikas;
for (Treniruote& t : treniruotes)
{
if (t.data == duotaData)
{
if (t.laikas == duotasLaikas)
{
t.vardas = t.pavarde = t.pratimai = "obolys";
}
}
}
}
void SukurtiTuscius(list<Treniruote> &treniruotes)
{
for (int i = 27; i <= 30; ++i)
{
stringstream diena;
diena << "2022.11." << i;
for (int j = 8; j <= 19; ++j)
{
stringstream valanda;
valanda << j << ":00-"<< j+1 <<":00";
Treniruote t;
t.data = diena.str();
t.laikas = valanda.str();
t.vardas = t.pavarde = t.pratimai = "nera";
treniruotes.push_back(t);
}
}
}
void ParodytiVisaTvarkarasti(list<Treniruote>& treniruotes)
{
for (Treniruote& t : treniruotes)
{
cout << t.data << endl;
cout << t.laikas << endl;
cout << t.vardas << endl;
cout << t.pavarde << endl;
cout << t.pratimai << endl;
cout << endl;
}
}
void salinti_pridėti(list<Treniruote>& treniruotes)
{
}
void ProgramosPabaiga(list<Treniruote>& treniruotes)
{
fstream file("planas.csv", ios::out);
for (Treniruote& t : treniruotes)
{
file << t.data <<","<< t.laikas << "," << t.vardas << "," << t.pavarde << "," << t.pratimai;
file << endl;
}
cout << "PROGRAMA BAIGTA";
exit(0);
}
int main()
{
int choice;
bool gameOn = true;
list<Treniruote> treniruotes;
struct tm newtime;
time_t now = time(0);
localtime_s(&newtime,&now);
auto month = to_string(1 + newtime.tm_mon);
auto day = to_string(newtime.tm_mday);
auto hour = to_string(newtime.tm_hour);
auto hour_pridėta = to_string(1 + newtime.tm_hour);
//sukuria .csv faila pagal irasyta pavadinima
//string fname;
//cout << "Enter the file name: ";
//cin >> fname;
// fstream file(fname + ".csv", ios::app);
//Menu
while (gameOn != false) {
cout << "*******************************\n";
cout << " 1 - Create empty weekly plan.\n";
cout << " 2 - Show the full schedule.\n";
cout << " 3 - Read the weekly work plan.\n";
cout << " 4 - Change the schedule field information.\n";
cout << " 5 - Find the given client's full weekly workouts\n";
cout << " 7 - Exit.\n";
cout << "*******************************\n";
for (Treniruote& t : treniruotes)
{
if (t.data == "2022." + month + "." + day)
{
if (t.laikas == hour + ":00-" + hour_pridėta + ":00")
{
cout << t.data << endl;
cout << t.laikas << endl;
cout << t.vardas << endl;
cout << t.pavarde << endl;
cout << t.pratimai << endl;
cout << endl;
}
}
}
cout << "*******************************\n";
cout << " Enter your choice and press return: ";
cin >> choice;
switch (choice)
{
case 1:
SukurtiTuscius(treniruotes);
break;
case 2:
ParodytiVisaTvarkarasti(treniruotes);
break;
case 3:
NuskaitytiIsFailo(treniruotes);
break;
case 4:
PakeistiReiksmes(treniruotes);
break;
case 5:
rastiKlientoInfo(treniruotes);
break;
case 6:
{
string duotasLaikas, duotaData;
cout << "irasykite norima data ir laika ,kada norite pakeisti langeli" << endl;
cout << "data(formatas(XXXX.XX.XX)):";
cin >> duotaData;
cout << endl;
cout << "laikas(formatas(XX:XX-XX:XX)):";
cin >> duotasLaikas;
for (Treniruote& t : treniruotes)
{
if (t.data == duotaData)
{
if (t.laikas == duotasLaikas)
{
treniruotes.remove(t);
}
}
}
}
break;
case 7:
{
ofstream file;
file.open("planas.csv", std::ofstream::out | std::ofstream::trunc);
file.close();
ProgramosPabaiga(treniruotes);
break;
}
default:
cout << "Not a Valid Choice. \n";
cout << "Choose again.\n";
cin >> choice;
break;
}
}
return 0;
}

Answer 1

You must not remove items from a list while iterating through a range-based for loop. Under the hood, the loop stores a begin and end iterator of the original list, and iterate all items between them, and attempting to remove items during the loop will make end unreachable.
Instead, you could simply use std::list::remove_if to remove all elements that satisfy a certain condition:
my_list.remove_if([a, b](const auto& element){
return element.a == a && element.b == b;
};