STL Quiz set doubt

#1

Q13. stl set iterator returned by insert
What will be the output of following C++ code?

#include <bits/stdc++.h>
using namespace std;
int main()
{
    set<int>s;
    pair<set<int>::iterator, bool> ret;
    s.insert(1);
    s.insert(5);
    s.insert(10);
    s.insert(3);
    ret = s.insert(10);
    cout<<ret.second<<endl;
    return 0;
}

0

Compilation Error

Runtime Error

1

My answer is 1

#2

http://www.cplusplus.com/reference/set/set/insert/

the parameters determine how many elements are inserted and to which values they are initialized

since 10 is already present in the set
hence second time u try to insert 10
it returns 0 ( since no element is added) and the setLL iterator returns the iterator pointing to the 10 that is already present in the container

#3

I thought that set store unique elements so 10 is already present and it’s second value is true(1) so it should return 1.

#4

bool basically is telling whether the value is getting inserted or not !

#5

so since the value is not getting inserted hence bool == 0