binary_search in c++ unexpected behaviour

Question

The following snippet is returning me 0. I expected it to be 1. What\'s wrong going on here?

#include 
#include 
#include 

        

Answer 1

binary_search says:

Checks if the sorted range [first, last) contains an element equal to value. The first version uses operator< to compare the elements, the second version uses the given comparison function comp.

Your list is not sorted, it contains the elements 11 and 22 prior to 10.