Question

I feel like I might be overlooking something very extremely simple here, but I have made some code just to test out insert / splice on lists and I am getting a seg-fault on the code I made. Can someone tell me where / why?

#include <iostream>    
#include <vector>
#include <list>

using namespace std;
int main(){

vector <int> iVec;
list <int> iList;
vector<int>::iterator vIt;
list <int>::iterator lIt;

for(int i = 0; i < 10; i++){
    iVec.push_back(i*10);
    iList.push_back(i*10);
}//0, 10, 20, 30....90


//0 <-- current pos of iterator lIt

lIt++;  
lIt++; 

//0, 10, 20

iList.insert(lIt, 3);



//Vector output loop
for(vIt = iVec.begin(); vIt!= iVec.end(); vIt++){

}



cout << endl << endl <<"List Contents: " <<endl << endl;
//List output loop
for(lIt = iList.begin(); lIt != iList.end(); lIt++){
    cout << *lIt << endl;
}


return 0;

}

Answer 1

lIt has not been correctly initialized – it is an iterator – but currently does not point to anything – you need to do this:

lIt = iList.begin(); // initialize it to begin, now we can iterate!