// https://cirosantilli.com/linux-kernel-module-cheat#cpp

#include <cassert>

#include <set>

int main() {

std::set<int> s{0, 2};

// Insert another element.

auto insert_ret = s.insert(3);

assert(insert_ret.first == s.find(3));

assert(insert_ret.second == true);

// Insert something already there, second of return is false.

insert_ret = s.insert(3);

assert(insert_ret.second == false);

// Check if a value is present.

auto zero = s.find(0);

assert(zero != s.end());

assert(*zero == 0);

// Now for a value that is not present.

auto one = s.find(1);

assert(one == s.end());

#if __cplusplus > 201703L

// In C++20 we finally have a .contains() to avoid the end mess!

assert(s.contains(0));

assert(!s.contains(1));

#endif

// Remove an element.

// Was present, so return 1;

assert(s.erase(0) == 1);

assert(s.find(0) == s.end());

// Not present, return 0.

assert(s.erase(0) == 0);

}