CPP

unordered_set to vector

Before C++17
vector.insert(vector.end(), set.begin(), set.end());

After C++17
vector.reserve(set.size());
for (auto it = set.begin(); it != set.end(); ) {
    vector.push_back(std::move(set.extract(it++).value()));
}

move elements from vector to unordered_set

#include <iostream>
#include <vector>
#include <unordered_set>
 
int main()
{
    std::vector<int> input({ 1, 2, 2, 1, 3, 1, 4 });
 
    std::unordered_set<int> set(input.begin(), input.end());
 
    for (const int &i: set) {
        std::cout << i << " ";
    }
 
    return 0;
}