std:vector中的断言错误用于std :: set_difference

#include<iostream>
#include<vector>
#include<algorithm>
#include<iterator>

int main() {
    std::vector<int> a = {1, 2, 3, 4, 5};
    std::vector<int> b = {3, 4, 5, 6, 7};
    std::vector<int> result;

    std::set_difference(a.begin(), a.end(), b.begin(), b.end(), std::back_inserter(result));

    std::cout << "The difference between a and b is: ";
    for (int i : result) {
        std::cout << i << " ";
    }

    return 0;
}

The difference between a and b is: 1 2